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Backyard Fruit Production
Discussion: Growing fruit in the backyard can be a very rewarding experience but often times it is a challenge to produce edible fruit in a backyard setting. Site selection, variety selection, pruning, and pest control are not given enough consideration by the average homeowner prior to planting. A tremendous amount of information is available concerning tree fruits and small fruits and throughout this program references will be made to resources providing additional information. This program was developed to assist homeowners in the establishment, culture, and hopefully the harvest of high quality tree fruits and small fruits.
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The Basics Variety Selection - select adapted varieties
Site selection - know fruit’s soil, light and moisture requirements Soil fertility - know fruit’s nutrient requirements Understand the basics of soil fertility Pest control - plan for control of pest problems Discussion: Variety Selection - it is important to select varieties that are adapted to eastern Oklahoma. Site selection - knowing the soil, light and moisture requirements of the fruit is essential in selecting a planting site that is well suited for the plant. Soil fertility - it is important to know the nutrient requirements of the fruit that is being grown. It is also important for growers to understand the basics of soil fertility. Pest control - all fruit is susceptible to attack by disease and insect pests. Growers need to plan for control of these problems in order to produce edible fruit.
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Soil Texture Soil texture = Relative proportion of sand, silt, and clay in the soil. 3 particles Sand - largest - gritty Silt - intermediate - powdery Clay - smallest - rubbery Extreme of any one particle type is undesirable. Inset picture: Line drawing of “Textural triangle”. Discussion: Soil type is critical to fruit production. Some fruit trees have a very difficult time of surviving on heavier types of soil during times when the soil remains wet for more than 48 hours. The three soil textures in different combinations and ratios make up all soils. An ideal soil is going to contain all three particles. Too much sand leads to increased moisture stress and increased irrigation costs. Too much clay leads to drainage problems and greatly limits the crops which can be planted on a particular site. *Presentation hint: Presenter may want to display topsoil in three containers to illustrate particle size.
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Soil Types Sand Leaching, drying Easy to till, good rooting Clay
Poor drainage, difficult to till, poor rooting Fertile Loam Free movement of water and air Good water retention Little resistance to tillage Organic matter improves sandy and clay soils Discussion: A loamy soil is the best for fruit production; however, there are some types of fruit that will grow and produce on sandy or clay type soils. The addition of soil amendments such as high amounts of organic matter will greatly improve the disadvantages of both a sandy and clay soil. It does decompose, so plan to add and work in a 2-inch layer each spring and fall. Additional information is available in the Oklahoma Soil Fertility Handbook. Refer to OSU Extension Fact Sheet #6436 entitled “ Earth Kind Gardening: Healthy Garden Soils”.
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Soil Depth Combination Topsoil and subsoil
Total of 4-6 feet is desirable Minimum of 10 in. of topsoil Discussion: The deeper the soil the greater the production potential. Shallow soils are going to have problems with moisture retention, fertility, and drainage.
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Slope > 10% offers problems Excessive runoff Erosion
Special management required South-facing slopes Earlier plantings Discussion: The disadvantages of too much slope are obvious. However, some slope can be desirable, especially in helping to avoid late spring frosts. In many cases a south facing slope is not desirable for fruit crops, especially those that are susceptible to frost damage because of early bloom. In the case of apricot and peach, a south facing slope is not recommended.
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Air Movement Pest considerations Damage to seedlings and transplants
Drift from adjacent properties Adjustments Barriers Fencing Discussion: Air movement can be good and bad. Too much wind can lead to sand blasting of strawberries and blueberries or the wind physically breaking the twigs and branches of young fruit trees. However, some air movement is desired to help avoid frost damage on peaches, brambles and strawberries. Air movement also helps to prevent the development of foliar diseases. Air movement can also lead to unwanted drift of pesticides, particularly herbicides to a non-target plant(s) and bring in airborne insect pests. 2,4-D drift can be extremely detrimental to many different fruits, i.e.. apple, pear, peach, nectarines, blackberry, blueberry and others.
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Soil Fertility Sampling pH Nutrients
Discussion: Soil fertility and why it is critically important to the growth and production of fruit.
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Soil Sampling Sample 15 to 20 random sites 6 inches deep
Combine and mix Take 1 pint to County Extension Office Inset picture: Soil probe, shovel and bucket with soil sample Discussion: Describe recommended procedure for taking a soil sample to submit to the OSU Soils Lab. Essential to test for soil pH and soil fertility. It should be pointed out that making fertilizer recommendations for a home orchard without the benefit of a soil test is similar to trying to determine how much gasoline it would take to fill a fuel tank without looking at the gas gauge.
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Soil pH scale Inset picture: Illustration of pH scale
Discussion: pH is a measure of soil acidity/alkalinity. On a pH scale 7.0 is neutral, less than 7 acidic, greater than 7 alkaline. Most plant nutrients are more available in mildly acidic soil (pH between 6.0 and 7.0). Soil with pH 5.0 is 10X more acid than soil with pH 6.0 and 1000X more acid than pH 7.
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Improper Soil pH Know the pH requirement of the fruit crop
Make necessary amendments to soil Soil test on regular basis to maintain proper pH Discussion: If several different fruit crops are grown in a backyard situation particular attention is going to have to be paid to amending the soil pH to fit the requirements of a specific fruit. For example, if blueberries and blackberries are grown, the blueberries require a lower pH than the blackberries. If the pH is not low enough where the blueberries are growing they will be chlorotic, stunted and produce low yields. On the other hand if the gardener lowers the pH too much in the blackberry area they will be chlorotic, stunted and produce low yield. Bottom line: know the pH requirement for each fruit grown and amend the soil to the recommend pH in the specific site where that fruit is growing or is to be grown.
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Correcting pH problems
Too acid - add lime Too alkaline - add sulfur Inset pictures: Bags of Hydrated Lime and Sulphur Discussion: Refer to “Oklahoma Soil Fertility Handbook” and “Oklahoma Homeowner’s Handbook for Soil and Nutrient Management” for information on correcting soil pH problems.
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Soil Nutrients Macronutrients Micronutrients
Discussion: Refer to “Oklahoma Soil Fertility Handbook” and “Oklahoma Homeowner’s Handbook for Soil and Nutrient Management” for information on correcting soil pH problems.
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Macronutrients N, P & K N = Nitrogen P = Phosphorus K = Potassium
Inset pictures: Three photos of nutrient deficiencies Discussion: The inset photo under N is a peach leaf expressing symptoms of N deficiency. Foliage is yellow-green. The older foliage begins to yellow first. N is one of the primary building blocks for amino acids, protein and plant protoplasm, it is critical for flower differentiation, rapid shoot growth, bud vigor and fruit set. N also increases the size and quality of fruit and acts as a catalyst for other nutrients. The inset photo under P is phosphorous deficiency in apple. Note the purplish blotches on the leaves. P hastens maturity, is involved in energy transfer and storage, the formation of nucleic acids and in RNA and DNA formation. It promotes root, flower and seed development. The inset photo under K is potassium deficiency in apple. Note the leaf distortion and curling. K is an enzyme activator. It is necessary for the formation of sugars, the synthesis of proteins and cell division. It improves cold weather tolerance, helps regulate fruit acidity, improves coloring of grapes and apples by aiding in anthocyanin synthesis. Refer to the “Oklahoma Soil Fertility Handbook” for more information on the macronutrients.
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Micronutrients Ca, Mg, S (a.k.a... Secondary nutrients)
Fe, Mn, Cu, Zn, B, Cl, Mo Discussion: Stress that micronutrient deficiencies are not normally a problem. However in some of the acid loving fruit, occasional Fe or Zn deficiencies may be observed if the soil pH is too high. The inset photo is a cluster of grapes expressing Zinc deficiency. Zinc deficiency can cause reduced set, fruit development and size. Other micronutrient deficiencies cause symptoms on the plant and/or fruit that often can provide a clue to which nutrient is deficient. Refer to the “Oklahoma Soil Fertility Handbook” for more information on the micronutrients.
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How Much Fertilizer to Apply
Interpreting OSU soil tests Inset picture: Contains an example with recommendations of results of soil test. Discussion: Explain Buffer Index, and meaning of the N, P & K values. Explain how to calculate the amount of fertilizer needed for small areas of less than 50 ft2 from recommendations for pounds/acre or pounds/1000 ft2. Refer OSU Extension Fact Sheet #6232 “Fertilizing Pecan and Fruit Trees” for more information on fertilizing fruit trees. Refer to the “Oklahoma Soil Fertility Handbook”, “Oklahoma Homeowner’s Handbook for Soil and Nutrient Management” and the “Study Guide” for examples on how to calculate amount of fertilizer to apply to a small area.
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Understanding Fertilizer Analysis N
P2O5 K2O Inset picture: Bag of commercial fertilizer ( ) Discussion: Explain how to interpret the analysis information on a bag of commercial fertilizer. Explain difference between homogenized and blended fertilizers. Explain importance of determining analysis of organic fertilizer. Refer to “Oklahoma Soil Fertility Handbook” and “Oklahoma Homeowner’s Handbook for Soil and Nutrient Management” for more information concerning fertilizers.
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Selecting Fertilizer to Meet Recommendations
0-0-60 34-0-0 0-46-0 Inset picture: Bag of commercial fertilizer analysis Discussion: It is often difficult to find a blended commercial fertilizer or an organic fertilizer which meets recommendations of the OSU soil test. In some cases two different commercial fertilizers may have to be purchased and blended in order to satisfy the OSU recommendation. For example, over the years many home gardens have been heavily fertilized with the commercial fertilizer This has led to many garden soils being extremely high in P while needing additional N and K. To meet the OSU recommendation a gardener is likely to have to apply a or some other nitrogen fertilizer and This would provide both of the needed nutrients without adding more P. It should be noted that home gardeners who habitually over fertilize are running the risk of becoming a non-point source of contamination for excessively high levels of N and P in their garden soil, and too much of some nutrients can cause nutrient toxicities which result in limited plant growth and production. Refer to the “Oklahoma Homeowner’s Handbook for Soil and Nutrient Management” and the “Oklahoma Soil Fertility Handbook” for more information on soil fertility.
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Fertilizers Organic Commercial
Inset pictures: left - Muriate of Potash; mid-lower - Bone Meal Discussion: Proper fertilization is a key component to successful fruit production. Too little fertilizer leads to reduced production. Too much fertilizer can lead to toxicities or in the case of over applying nitrogen, plants may remain in a vegetative state and produce very little if any fruit. In general, February through March (or at least 3 to 4 weeks before spring bud break) is the preferred time to fertilize fruit trees in Oklahoma. In the case of peaches a split application may be advisable because of its vulnerability to spring frosts. The last application on peach should be made following fruit set. Many people worry about fertilizing young trees. Most native soils have adequate nutrients to get a tree up and going its first few years. See guidelines above for pre-planting soil preparation. Nitrogen is usually the only limiting nutrient….small, pale green leaves may indicate a need for supplemental N. In succeeding years follow the recommendations of a soil test or the general guidelines in OSU Fact Sheet No “Fertilizing Pecan and Fruit Trees”. Unless a grower has a preference there is no actual advantage of using organic fertilizers over commercial fertilizers except the organics will add some organic matter to the soil. But in doing this they will also retain or tie up the N until the organic components are broken down. Explain that plant nutrients are absorbed by the plant in the same form whether they come from organic or inorganic fertilizers. Refer to OSU Extension Fact Sheet #6232 “Fertilizing Pecan and Fruit Trees” for more information on fertilizing fruit trees.
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Pests of Fruit Weeds Diseases Insects
Inset pictures: Examples of each of these pests. Discussion: The following slides present general information about weeds, diseases, and insects. The points discussed apply in a broad sense to all fruit.
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Weed Control in Fruits Inset pictures: Three examples of “weed free” fruit crops; upper left - strawberries; lower left - raspberries; right - peaches Discussion: Fruit crops will be more productive and more attractive if good weed management practices are used. You should begin thinking about weed control before establishing a new planting.
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Harmful Effects of Weeds
Weeds rob water and nutrients Weeds block sunlight Weeds may contribute to insect and disease problems Weeds complicate care Discussion: Weeds are harmful to fruit production for several reasons. Weeds use water and nutrients needed by the crop plant. Weeds may also prevent fruit plants from receiving all the sunlight needed for optimal growth. All these factors can result in less vigorous plant growth. Weeds may attract or harbor insects that can be harmful to the crop. Weed infestation may contribute to conditions that favor certain diseases.
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Weed Control Methods Avoidance - Plant weed free site
Prevention - Use practices that do not introduce or favor weeds Removal - Stop weeds that get started Discussion: Weed control is best accomplished using a combination of practices to keep weeds from getting started and creating a problem that is difficult to control.
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How to Avoid Weeds For new plantings:
Choose a site free of poison ivy, johnsongrass, bermudagrass, nutsedge, woody plants, etc. Remove troublesome weeds from site before planting Start a year in advance! Discussion: When establishing a new planting, try to avoid sites where weeds that will be difficult to control are present. Collect a sample of the plants growing where you want to put your fruit planting and take it to your County Extension Office to determine if there are any weeds that will be difficult to control. Perennial weeds such as poison ivy, nutsedge and bermudagrass should be controlled before planting the fruit crop. There are some herbicides available that can be safely used to do this. Check with your County Extension Office for more information.
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How to Prevent Weeds For established plantings:
Use mulch to prevent weed growth Do not mulch with weed-contaminated materials Control weeds while they are small Use herbicides Consult Your Extension Office Discussion: Once a planting is established, a good way to prevent weeds is to keep it mulched. The types of mulches that should be used depends on the kind of fruit crop you have. When using organic materials for mulch, such as straw or wood chips, be sure it is not contaminated with weed seed. On larger plantings, you may want to consider using herbicides. You should consult with your County Extension Office for the latest information on which herbicides can be used and how and when to apply them.
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How to Stop Established Weeds
For established plantings: Till soil shallowly Pull weeds while soil is moist Hoe while weeds are small Use herbicides Consult Your Extension Office Discussion: If weeds get established, they are most easily removed while small. If you need to hoe or cultivate, do so only as deep as is needed to remove the weeds. Deep tillage can injure roots. Once a weedy planting has been cleaned up, the application of mulch will help keep it this way.
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Diseases General Facts
Abiotic vs. Biotic Correct identification of the cause of the disease is essential to control Discussion: There are many diseases of fruit. Practically all fruits are attacked some time during their growing season by a pathogen that causes either foliar or fruit infections. There are some diseases, especially on grapes, strawberries and peaches, that if left uncontrolled will defoliate the plant and destroy the fruit. These diseases often have to be controlled with a fungicide in order to produce quality fruit.
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Abiotic Diseases Disease caused by environmental factors Examples:
Nutrient deficiency or excess High air temperature Low air temperature Low light Excessive light Soil compaction Pesticide toxicity Discussion: There are many factors which can cause abiotic diseases of vegetables. Nutrient deficiencies, improper light (low and high), temperature extremes and pesticide toxicities are common in fruit crops.
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Biotic Diseases Diseases caused by a pathogen that can spread from a diseased plant to a healthy plant Pathogens of biotic diseases Fungi Bacteria Virus Nematodes Discussion: Fungi cause the vast majority of diseases on fruit. However, there are also some major diseases caused by bacteria and viruses. In general it is much harder to control bacterial and viral diseases because there are few bactericides and no viricides available for use on fruit. During the discussion of biotic diseases mention the three components necessary for disease development, host, pathogen and proper environment (the disease triangle). Refer to the Study Guide for information on the “disease triangle” and for information on fungi, bacteria, viruses and nematodes. Note: A slide of “the disease triangle” is not included in this program. It is available upon request from Area Plant Pathology Office or the Department of Entomology and Plant Pathology.
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Proper Identification Is Essential for Successful Disease Control
1st - Disease vs. Insect 2nd - Abiotic vs. Biotic 3rd - ID pathogen Discussion: It is critical when making decisions on disease control to be able to distinguish between damage caused by insects versus that caused by diseases. Once insects have been eliminated as the problem, the next step is to determine if the disease is abiotic or biotic. If it is determined that the problem is a biotic disease, the next step is to determine the causal organism. Misidentification leads to unneeded and misapplied insecticides and fungicides. This type of error leads to increased cost of production, lack of pest control, and exposes the environment to unwarranted pesticide contamination.
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Common Biotic Diseases of Fruits
Foliar diseases Wilts and root rots Nematodes Discussion: Fungi cause the vast majority of diseases on fruits. However, there are some major diseases caused by bacteria, viruses and nematodes. In general, it is more difficult to control bacterial, viral and nematode diseases because there are fewer bactericides and nematicides and no viricides available for use on backyard fruit. Biotic diseases require three components for development. These components are host, pathogen and proper environment (the disease triangle).
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Control of Diseases Organic or non-chemical methods Chemicals
Discussion: There are two basic alternatives for obtaining control of diseases. All gardeners should employ as many organic or non-chemical methods as possible. However, in situations where foliar diseases have historically caused problems or when a foliar disease has become established on a plant or in a garden, chemical control is the best alternative.
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Non-Chemical and Organic Methods
Exclusion Sanitation Resistant varieties Eradication Crop rotation Soil sanitation Solarization Oven sterilization Cultural practices Discussion: All non-chemical methods have some positive effect on preventing plant diseases--some more than others. Certainly the use of resistant varieties has to be a first line of defense. Disease resistant varieties should be grown if it can be done without sacrificing production and quality.
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Cultural Practices for Disease Control
Properly space plants Properly prune and trellis when practical Avoid excessive soil moisture Plant on raised beds Improve drainage Avoid overhead watering Fertilize properly Discussion: Common sense practices generally help to prevent or reduce the amount of disease that occurs on fruit. Doing things such as proper spacing and trellising will help improve air movement which helps to make the environment less favorable for disease development. Avoid excessive soil moisture by not overwatering and improving drainage. Properly fertilized plants are more vigorous and therefore more resistant to diseases.
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Proper Use of Fungicides in Backyard Fruit Orchard
Importance of spray schedules Commit to a spray schedule or don’t spray Spray at the recommended growth stage Selection of a fungicide Based on host and pathogen Waiting periods Discussion: Fungicides are protectants which prevent fungal spore germination and subsequent fungal penetration of plant tissues. Protectants are applied repeatedly to cover new plant growth and to replenish the fungicide that has deteriorated or has been washed off by rain or irrigation. Refer to the Study Guide for more information on fungicides.
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Fungicides Recommended for Fruit
benomyl (Benlate) captan (Captan) chlorothalonil (Daconil ) lime sulfur mancozeb (Dithane M-45 , Dithane F-45) triademefon (Bayleton) triforine (Funginex) Caution: Different fungicides labeled for use on different fruit crops. Check the label. Discussion: The most broad spectrum of these fungicides are chlorothalonil, mancozeb, and maneb. These control many different foliar diseases and fruit rots. Fungicides followed by the letters DF are dry flowable materials that will be applied as a liquid spray, F indicates a flowable material. Most of these fungicides are not labeled for use on all fruit therefore refer to the label before applying. Some fungicides are somewhat specific for the disease they control, such as Bayleton, which is an excellent control for powdery mildew but of no value for controlling many of the other diseases that attack fruit crops. Note: The list of fungicides cleared for use on fruit changes frequently. The presenter should check the latest edition of the OSU County Agents’ Handbook to verify that all the fungicides listed on the slide are still cleared on fruit.
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Factors Concerning Insect Control
Producing edible crop = primary goal Arthropods represent = major problem Spraying = most important cultural practice 25-50% of total cost of production Resistance to pesticides Environmental concerns Food safety Discussion: Insect control is a major consideration for fruit growers. Many insects will damage or lower the quality of fruit produced while some species, if not controlled, will destroy the entire plant. Anyone desiring to grow fruit should become acquainted with the major species and develop a plan for insect control or they will be disappointed at harvest time. Some fruit will require a rigorous spray schedule while others can be grown with minimal insecticide use. Alternative solutions to spraying insecticides can sometimes be used successfully and these other methods should be pursued when possible. However, most growers will find it necessary to apply insecticides to successfully grow fruit. It is important to consider resistance, environmental concerns, and food safety. Refer to F-7450 “Safe Use of Pesticides in the Home and Garden”, F-7454 “Check Your Pesticide Labels”, and F-7457 “Toxicity of Pesticides”.
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Arthropod Development and Damaging Stages
Life cycles Number of generations Host plants Seasonality Overwintering Movement Susceptibility Inset picture: Diagram of arthropod life cycle Discussion: Insect pressure varies depending on the species. Life cycles and numbers of generations are especially important from the standpoint of control. A pest with one generation per year is much more predictable and easier to manage than pests with multiple generations. Finding a weak link in the life cycle can aid in control. If a pest overwinters in the immediate area or on the plant, a grower can reduce the number of pests by using good cultural practices, applying dormant sprays , etc. By becoming familiar with pests, one can also utilize pheromone traps, mechanical barriers, and other non-chemical control methods to minimize insect infestations. Refer to Mid-Atlantic Orchard Monitoring Guide, West Virginia University, NRAES-75, Common Tree Fruit Pests, Michigan State University Extension, NCR 63, Insect and Mite Pests of Grapes in Ohio, Ohio State University Extension Bulletin 730, Growing Small Fruits in Home Gardens, University of Tennessee Extension PB902, Controlling Diseases and Insects in Home Fruit Plantings , Ohio State University Extension Bulletin 780, Growing & Using Fruit at Home Cultural Practices and Pest Management, Ohio State University Extension Bulletin 591, Insect Pests of Strawberries in Ohio, Ohio State University Extension Bulletin 667, Insects on Deciduous Fruits and Tree Nuts in the Home Orchard, USDA-Home and Garden Bulletin no. 190.
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Spray Calendars Written for worst case scenario
Assumes all pests are present Production of fruit under severe infestations Followed by most growers Could/should be modified Discussion: In order to harvest an edible fruit crop, spray schedules have been developed for tree fruits and small fruits. These schedules are designed to control insects throughout the growing season. They are followed closely by many growers. In some instances, fewer applications of pesticides might suffice, since these schedules are written for worst case scenarios and assumes all pest species are present throughout the growing season. These schedules allow for harvest of fruit crops under heavy insect pressure and have been followed by most growers for years in the past. Scouting efforts are not required when spray calendars are followed. The biggest change in insect control has been in the recommendation of pesticides without any changes in timing. In many cases, fruit, especially in the backyard, could be monitored more closely and perhaps fewer applications could be made. Acceptance of some cosmetic damage by growers would also allow for reduced pesticide usage. Refer to OSU Fact Sheet #6235 “Home Fruit Spray Schedules” and OSU Current Reports #’’s 6221, CR-6240, CR-6241.
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Beneficials Parasitic wasp Lady beetle Minute pirate bug
Inset pictures: Upper right - parasitic wasp; lower right - mature lady beetles; lower middle - lady beetle larva; lower left - minute pirate bug. Discussion: Fruit growers should rely on beneficials for natural control as much as possible. The unnecessary use of pesticides and the poor choice of insecticides contribute to the loss of beneficials and the increase of pest problems. Identification is important and chemicals should be applied only when absolutely necessary.
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Modified Spray Programs
Extended Interval Spraying Petal fall cover 21 day intervals Strip Spraying Include outsides and ends Reduced Dosage Spraying Spray on schedule using lower rates Spray As Needed Requires scouting / monitoring Discussion: All the modified spray programs are based on close observations. If fruit growers adopt a modified spray program, fruit plantings should be monitored and some damage from pests may be inevitable resulting in lower quality fruit. Reduced pesticide usage is the advantage of following this kind of approach to arthropod control. Some pests are relatively minor and present only a cosmetic or surface injury while others may cause total loss of the crop or death of the plant.
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Oils for Insect Control
‘ Dormant Oils ’ Apply before leaf or bud swell Emulsifier allows for mixing with water Effective for scale insects ‘ Delayed-Dormant ’ Green tip to 1/2 inch green bud Effective for mite eggs Called superior or supreme 2% Solution ( 2 0z / gal of water ) Avoid use below 40 degrees ‘ Summer Oils ’ Developed for use in summer Never mix with insecticidal soaps Discussion: Oil is generally considered an organic treatment. It is used to control pear psylla, mites, and scale insects on tree fruits and is usually applied during the late-dormant to green-tip stage. To avoid severe injury to the trees, do not apply when temperatures are likely to fall below 40 F within 24 hours. Thorough coverage of all bark surfaces is very important for oil sprays to be effective. An early season spray should minimize the use of pesticides during the remainder of the season. There are a variety of horticultural oil products available and their names are sometimes confusing. ‘Dormant Oils’ are intended to be used before the leaf or fruit buds open in the spring. These sprays are especially effective for scale insects. ‘Delayed Dormant’ sprays are applied at the green tip through half-inch green bud growth stage. Mite eggs are most susceptible to control by oil when they are close to hatching. After half-inch stage dormant oils can injure leaves. Superior, Supreme, or more precisely a “70-second viscosity” oil is used for delayed- dormant applications. Summer oils have been developed for use on foliage during the summer without phytotoxic effects. Oils and insecticidal soaps should never be mixed for application. Household or automotive oils cannot be used because they will not mix with water and are not formulated for use on plants. These types of oils will not provide insect control and will harm plants. Refer to HYG “Oil and Other Early Season Sprays for Apple and Pear Trees”, Ohio State University Extension Fact Sheet.
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How Much Pesticide HT SPREAD GALS 5-8’ 3-6’ 0.5-1.0 8-10’ 4-8’ 1.0-2.0
5-8’ ’ 8-10’ ’ 10-15’ ’ 15-20’ ’ Discussion: Carefully mix only the amount needed to spray a fruit planting. In general, sprays are applied to plant surfaces until all plant parts are thoroughly covered and spray material starts to drip from the treated surface. Always start by spraying the top of the tree and work down to the lower branches. From the accompanying chart, 1 to 10 gallons of mixed spray may be needed to provide thorough coverage of fruits, depending on size of the target plant. These amounts are based on fully leafed plants; less spray would be needed for dormant sprays when leaves are absent.
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Tree Fruits Pome Fruits - Pears, Apples
Stone Fruits - Peaches, Nectarines, Apricots, Cherries, Plums Inset picture: Apples and nectarines. Discussion: Growing tree fruit in Oklahoma requires planning, patience and skill. Proper rootstock and variety selection as well as pest control are essential. Site selection is critical to successful establishment of fruit crops. Measures can be taken to overcome less than ideal slope, fertility, and air movement, but it often takes more work and time to change the effects of shallow soil, soil texture, soil depth and drainage. Sometimes very little can be done to increase the amount of sunlight which an orchard or garden site receives. Establish an orchard or garden in areas which receive at least 6 to 8 hours of full sun per day. The points listed as considerations in selecting a site are extremely important in successfully growing fruit. Soil texture, soil depth, drainage, fertility are critical to successful establishment of the fruit crops that are targeted in this program. Not all sites are well adapted for fruit production. Careful evaluation of a site should be undertaken prior to committing time, labor and money establishing a fruit crop.
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Tree Fruits Ranked on Ease of Growing
Pears Easy Apples Cherries Peaches Nectarines Plums Apricots Difficult Discussion: These tree fruits are ranked from easiest to grow to most difficult. They will be discussed in the order listed so gardeners can categorize them as either pome fruits or stone fruits.
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Pome vs. Stone Pome vs. Stone
Tolerate clay soils Fewer disease and insect problems Less likely to suffer frost damage Stone Will not grow on clay or wet soils Several major disease and insect problems Bloom early in spring susceptible to frost damage Discussion: In previous slide the first two types of fruit trees, pears and apples are pome fruits. They have a central core with several small seeds. Quince, crabapple and medlar are examples of minor pome fruits. All of these share common cultural requirements that will be covered in detail in this program. All have relatively fewer diseases problems than stone fruits and are more tolerant of heavy clay soils and less likely to suffer losses from late frost. Stone fruits have juicy flesh surrounding a stony pit. Peaches, nectarines, cherries, plums and apricots are all stone fruits. Consequently, they have common cultural needs and also share similar disease and insect problems. As a result they will be covered in general in terms of pruning, insects and diseases. All stone fruits need very well drained soils to thrive in Oklahoma. In general pome fruits are much easier to grow than stone fruits. Less attention has to be paid to site selection and pest control when pome fruits are being grown. Stone fruits can be successfully grown but are going to require much more attention to pest control and planting site.
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A Grower’s Calendar January February March April May June
Order Trees Plant Trees, Frost Protection, Pruning, Dormant Pollination Check Oil First Sprays April May June Spray, Thin Fruit Spray, Train Trees Spay, Train Trees Mulch, Irrigate July August September Spray, Harvest Harvest, Irrigate Harvest October November December Clean orchard floor Fall Fungicide Spray Check for rodents Winterize irrigation Discussion: Growing good tree fruit is a year-round project. Gardeners will benefit by marking these activities on a calendar, then note planting, spraying, thinning and harvesting dates as they occur. After a few years, it’s nice to have a record of these events to continue fine tuning our skills.
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Planning Site selection Rootstocks/Varieties Number of trees
Sources of trees Planting plan Training plan Spraying Plan Discussion: Consider all these points before ordering the first tree.
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Site selection Deep, well-drained soils No frost pockets
Stone fruits on best-drained site Pome fruits on heavier soil Berm up soil if needed Inset picture: Cherry tree growing as landscape plant. Discussion: Air drainage is also critical for stone fruits. They bloom before pome fruits and are more prone to early spring frosts and freezes. Plant stone fruits where they’ll have the best air drainage, avoiding frost pockets. Small fruits can be worked in among vegetable and flower plantings. They can also be used as ornamentals….asparagus, blueberries, and grapes are particularly attractive in the landscape. Strawberries can be used as a groundcover, however, yields will not be as high as in open rows that receive more sunlight. Tree fruit can also be dispersed among the landscape. They do not have to be straight rows as on a farm. Also, a neighbor may already have similar fruit trees that could serve as pollinators. Lastly, all tree fruits are candidates for training to a flat trellis….espalier. This can be a fascinating hobby and add decor to the south- or east-facing wall of a home. Tree fruit can be grown on most any soil in Oklahoma. However, if the pH is too acidic or alkaline, certain nutrients may not be available. Also, P and K, which are essential for good root formation, flowering and fruiting, are not mobile nutrients. If a fertilizer containing these nutrients is surface applied at planting, it will take years to get worked into the soil and available for uptake by the plant. It’s best to have an OSU Extension Soil Test done before ordering trees. Allow three weeks for results to be returned. Fall is an ideal time to sample the soil, so that any lime and slow-release nutrients, such as P and K, can be worked into the soil prior to late winter planting.
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Rootstocks & Varieties
Rootstocks determine tree size and pest resistance Varieties determine fruit characteristics and pest resistance Both should be carefully selected Discussion: OSU Fact Sheet #6222 “Home Fruit Planting Guide” discusses rootstocks of individual fruit trees at length. This will also be covered as each fruit is discussed. Most fruit trees are harvested in the nursery as a bare-root tree and held in cold storage before shipping. Many retail nurseries buy these, pot them up, and sell them as container plants. They are not, however, container grown, and may have lost a good bit of their root system in the process. Purchase trees in winter as soon as they are available to ensure fresh bare-root stock.
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Number of Trees Two each of apples, pears and plums for cross pollination One each of all others Example: One peach tree yields four bushels of fruit…..how much do we want to have on hand to process???? Discussion: It is tempting to plant many kinds of each fruit….but, then we quickly run out of space and time to care for them. It is far better to plant just a few trees of favorite varieties and take good care of them, than to have a large, somewhat neglected planting. One peach tree will bear up to four bushels of peaches. Think about how these will be harvested and stored before planting too many trees. Also, large trees use up to two gallons of pesticide spray per tree each time they are sprayed. Over planting increases the need for pest control, pruning and other chores. The minimum to plant for a successful planting would be two of each kind of fruit tree. This ensures cross pollination of those that need it and attracts more insects to self-pollinating trees if more than one tree is in bloom at a time. Plan on trees occupying around 1/8 to 2 ¼ acre of space. An average family fruit planting, including small fruits, may need up to acre of space.
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Sources of Trees A reputable dealer familiar with variety and rootstock. Order in early winter Avoid recently potted “container grown” trees Plant bare root trees upon arrival Discussion: Once a tree’s variety and rootstocks are selected, be sure to take the time to buy from a reputable nursery. Do not buy fruit trees if the rootstock is not also listed on the label. This may mean that they were raised from seed and the outcome will be unreliable. Likewise, they may be grafted to a rootstock that is not adapted to our climate.
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Planting Plan Choose north or east slope Peaches on highest ground
Plant like fruits together for spray and pollination compatability Allow 20 x 20 feet for each tree or train on a trellis Mulch and maintain 5 feet diameter weed- and grass-free zone Discussion: Unless trees are trained to a trellis, they need plenty of space….about 20 x 20 feet per tree (400 square feet). This means careful consideration should be given to where they will be planted. Keep fruit type in mind when planting trees in the garden. If the garden is sloping, place the stone fruits on the most upland site for good water drainage. Apple trees could be further down-slope with pear trees at the lower end where drainage may not be ideal. Tree fruits will live from 12 to 50 years in a backyard. They get very large and require full sun for best growth. Plan where trees are are to be located and have everything ready for planting before getting the trees. If mail ordering, they may arrive earlier than expected. If so, heel them in, in soil outdoors. Never put trees in a bucket of water to hold before planting, as roots may die from lack of oxygen. Keep in mind that roots grow out before they grow down into the soil. A deep, narrow hole is not as conducive to new root growth as a wider saucer-shaped hole. Dig the hole about 15” deep by three feet in diameter. In a commercial planting, a power auger would be used, but in a small garden setting, a hand dug hole is acceptable. Extra care can and should be taken to ensure good first year growth. First, trim all roots to 18” long. New roots develop first at the end of existing roots. If roots are left too long, new roots will sprout more deeply in the ground. At deeper depths there is less oxygen and this is detrimental to the survival of the young roots. Trimming roots is not harmful. Make a small mound of soil in the hole. Place the tree in the hole spreading roots out over the mound making good root to soil contact. Make sure the graft line will ultimately be two inches above the final soil grade. Backfill with a portion of the original soil mixed with water. Continue layering soil and water until the hole is completely backfilled. Wrap the trunk in kraft paper tree wrap or paint the trunk with white, interior later paint or whitewash. Any of these methods will serve to shade the tender bark of the new tree, preventing sunscald. Hardware cloth or chicken wire should also be loosely placed around the trunk to prevent rodent damage. Some young trees can be pruned at planting time. Peaches, in particular, benefit by being pruned back to about 24 to 30 inches in height. Mulch the tree with two to three inches of shredded bark, pecan hulls or other woody mulch. This will moderate soil temperatures and hold in moisture. Spread mulch out to cover the full three foot diameter of bare soil created by the planting hole.
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Training Plan Begin the first year All trees: wide crotch angles
Pome Fruits: central leader Stone Fruits: vase shape….keep center open Inset picture: Wide crotch angles on apple tree. A spacer is also visible in the center of the picture. Discussion: “As the twig bends so grows the tree”…the saying goes. This is never more true than when we train fruit trees. Small changes in branch angles when shoots are young and supple can result in wide, strong crotch angles later in the tree’s life. Pears, apples, peaches, and nectarines need particular training early in life. The other stone fruits need no specific care…. they tend to naturally grow in a vase shape with a need for only occasional branch training.
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Spraying Plan Regularly scout for pests Follow spray schedule
Plan to spray from dormant season until within two weeks of harvest First three sprays after bloom are the most critical Inset pictures: Top and Middle - Man studying pesticide information and pesticides; bottom - pesticide protective equipment (gloves and goggles). Discussion: Know which pests to expect and learn their habits. Then, regularly check for those pests, fine tuning the timing of the Home Fruit Spray Schedule. This can be done by noting on the calendar when we first observe pest egg laying, feeding and other activities. Dormant sprays are time well spent as they can prevent several overwintering stages of diseases and insects. Do not spray insecticides during bloom to avoid harming pollinating insects. Also, check the label to determine when to cease applying a product at the proper interval before harvest. Use a sprayer powerful enough to reach tree tops. If trees are overhead, wear a rain hat and face shield to avoid spray exposure to falling droplets.
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Pollination and Fruit Production
Inset picture: Bee pollinating a flower Discussion: Pollination of trees is foremost in deciding how many trees should be planted. Refer to OSU Fact Sheet No. 6222: “Home Fruit Planting Guide” to determine specific pollination requirements. In general, all fruit trees need insects for pollination: Honeybees, bumblebees, orchard mason bees and others usually live near our homes and will pollinate the trees for us. Although all of these trees have perfect flowers (containing both male and female parts) the pollen is not always compatible. This is nature’s way of ensuring that the offspring borne within the fruit is the product of two parents. When seeds of these fruit are planted they rarely yield a tree that bears fruit identical to parent….due to cross-pollination. Pome fruits need two varieties to each type for cross-pollination. For example, we need to plant both a ‘Gala’ and a ‘Golden Delicious’ apple to get both to set fruit adequately. Some trees, such as the ‘Magness’ pear, are pollen sterile (male sterile). They need at least two other pear varieties planted nearby in order to set fruit. Many stone fruits are self-fruitful, or self-pollinating, meaning only one variety is needed for pollination and it can set its own fruit. Insects are still needed, however, to do the job of moving the pollen from the anthers to the stigma. Refer to OSU Fact Sheet #6222 “Home Fruit Planting Guide” for details on each tree and its pollination needs.
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First and Second Year Care is Critical
Weed Water Prune and Train Mulch Control Insects and Diseases Inset picture: Second-year peach tree Discussion: As with a small child, early care is a determinant of success at maturity. Many home orchards are planted correctly, yet not maintained. Weeds, particularly bermuda grass, can effectively suppress the growth of a young fruit tree preventing it from ever reaching its full bearing potential. The result can be a small, stunted tree that delays what will surely be a poor crop. Weeding and watering are of paramount importance the first two years of a fruit tree's life in our gardens. Make sure trees receive one inch of water per week in the heat of the summer. A slow trickle from a garden hose, or a soaker hose, is much better than standing there spraying the soil surface….this encourages erosion and soil compaction and usually doesn’t provide enough water.
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Care of Young Trees Remember: Control weeds and provide adequate water the first two to three years. Inset pictures: Hoes, soaker hose and container of Roundup Discussion: Young, non-bearing fruit trees do not need to be on a regular spray schedule. If leaf-chewing insects have removed up to 15% of foliage, then try to I.D. the pest and spray accordingly. Young trees do need limb training, (see above), as well as protection of the bark from rodents and deer.
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Weeds in Tree Fruits Weeds slow young tree establishment
Control weeds to the drip line Use shallow cultivation only See OSU Current Report CR-6242 Inset picture: Weed-free zone below peach trees Discussion: Even though tree crops usually tower over weedy plants, tree roots are often shallow and low growing weeds can interfere with tree growth. This is especially so with newly planted trees. Uncontrolled weed growth may delay by several years the time needed for trees to begin producing. Control weeds as far out as the foliage reaches. Organic materials or woven plastic mulches may be used to prevent new weeds from getting established. If cultivation and hoeing are used, go only as deep as necessary to remove the weeds. If trees are surrounded by lawn or meadow, keep the vegetation adjacent to the tree drip line mowed short. Tree roots often go well beyond the drip line.
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Pome Fruits Apples and pears easiest to grow
Choose disease-resistant varieties Train to central leader Bears after 3 to 5 years Fruit stores well Inset pictures: Apple and pear fruit Discussion: Apples and pears, like most plants, prefer deep, medium textured, well drained, fertile, and easily worked soils. However, these fruit trees will do reasonably well where the soil has a high water table, is poorly aerated, or is too heavy textured for most other deciduous fruits. Sites with good air drainage will help prevent some of the diseases that infect pome fruits.
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Apple Rootstocks and Varieties
MM-111 semi-dwarf rootstock Select varieties for: heat and cold tolerance (zones 6&7) disease resistance flavor Inset picture: Apple tree: note graft union between the variety and rootstock Discussion: The Malling-Merton 111 rootstock is named for a research station in England. It has proven, over time, to be ideal for apple trees in Oklahoma. Many varieties are available already grafted onto MM Select varieties from the list provided in the OSU Fact Sheet #6222 “Home Fruit Planting Guide” or from the list provided in the Study Guide.
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Training Apples Central leader 5 - 7 scaffold limbs
Encourage fruit spurs Prune away crown suckers and water sprouts Inset pictures: Lower left - 7 year-old apple tree illustrating central leader training and pruning system; upper right - fruiting spur. Discussion: Trees must have strong wide crotch angles to support a heavy crop load. A main objective of pruning is to select branches that will have this desired characteristic. A well-trained tree, in good shape, should only need light pruning each year to maintain the proper growth habit. Fruit spurs are small, branched groupings of flower buds that will bear fruit. Spur-type apple varieties bear more fruit over a compact growth habit.
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Growing Good Apples Thin dime size fruit to 6 - 8 inches apart
Spray regularly starting bactericide at 10% bloom and insecticides at 75% petal fall Fertilize only in late winter and late spring Harvest with slight upward twist and avoid bruising Discussion: Varieties susceptible to fire blight will need to be spayed with a bactericide beginning at 10% bloom through petal fall. Once apples have flowered and ¾ (75%) of blooms have fallen, begin spraying for pests such as codling moth. The case of wormy apples actually has its beginning right after flowering when moths lay their eggs on the developing fruit. In a few short weeks, fruit will grow to the size of a dime. At this stage of growth, gently knock limbs with an old rubber hose on the end of a pole, or use a child’s hollow plastic softball bat. Knock off all loose fruit. Then, by hand, remove enough fruit to leave a final spacing of one apple for approximately every 6 to 8 inches of limb. Apples may be in groups, due to their bearing habit. The ultimate purpose of thinning is to remove excess fruit in relation to the number of leaves on the tree, so that enough carbohydrates can be available to size up the remaining fruit. Remaining fruit still needs protection from insects and may receive hail damage. However, thinning ensures that what IS harvested is large enough and flavorful enough to enjoy eating and processing. Apply fertilizer as a split application: half in late winter, half in late spring. Avoid fall fertilization as this may stimulate growth at a time when the tree needs to go dormant. All trees develop winter hardiness and dormancy from the top down. So, the trunk is the last part to go dormant in fall. It is most susceptible to early fall freezes. Damage can be severe, including death of the tree due to ruptured vascular tissue. Wrapping or painting trunks of young trees may help prevent this problem.
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Pears The easiest no-spray fruit Asian pears …. crisp, juicy
European pears …. more flavor, softer texture All keep very well Inset pictures: Pear blossoms and pear fruit Discussion: Pears are often a problem free fruit. Some varieties are infected by some of the common pome fruit diseases and may require application of a bactericide or fungicide. Insects are a potential problem but do not attack pears at the same level of incidence as some other types of fruit. Pears can be classified into two broad groups - the European types (also referred to as French types) and the Asian types. European varieties are often high quality, good eating pears but are more susceptible to fire blight. Asian pears are a hybrid pear and are not as flavorful as common (European) pears and some varieties have the defect of producing gritty stone cells in the flesh of the fruit. However they are more resistant to fire blight. They are good for cooking.
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Pear Rootstocks and Varieties
Rootstock: ‘Old Home’ x ‘Farmingdale’ a.k.a.: (OHXF) All varieties must resist fire blight disease to thrive here Select also for freedom from grit cells for softer texture Discussion: As with apples, pay attention to rootstock and variety selection to insure success with pears.
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Training Pears Begin at planting Wide crotch angles Central leader
Avoid N fertilizer Never top them Inset picture: Young pear tree trained and pruned to central leader system Discussion: Pears naturally grow very upright until they bear fruit. If we top them to control height they’ll be stimulated to send up even more vigorous upright limbs. From the beginning, allow one central leader and spread remaining limbs at 45 degree angles from the main leader. Avoid N fertilization - it stimulates excess succulent upright growth.
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Growing Good Pears Thin fruit to 6 - 8 inches apart
Do not over apply N Spraying not as critical Protect ripening fruit from wasps and bees Harvest before fully ripe to store Discussion: As with apple trees, pears begin bearing in about four years. They likewise need pest protection and attention to thinning shortly after flowering ends in spring. However, many gardeners have abundant pear crops and never spray. If apples are nearby, pests such as codling moth will select them for egg laying site over harder, tougher-surfaced pears. Avoid over-fertilizing with nitrogen - the succulent growth that results is far more susceptible to fire blight disease. Some varieties of pears are susceptible to fire blight and will have to be sprayed with a bactericide beginning at 10% bloom through petal fall. One measure of maturity is fruit lenticels. These are the small 'dots' or indentations on the fruit's skin. Lenticels of immature pears are white; however, as cork cells develop, the lenticels become brown and shallow. The brown in the lenticels is a good indication that the fruit is ready to be picked and will ripen without shriveling. Color between the lenticels also becomes lighter green than at the lenticels. European pears can be picked before fully ripe. Store in a cool, dark place. Asian pears must be tree ripened for best flavor. Both are ripe when outer skin is golden yellow and flesh gives gently with pressure. Store Asian pears for several weeks at high humidity and around 40 degrees F. Wasps and bees will often be attracted to ripening fruit seeking the sugary juice. The fruit can be protected with fine “wedding veil” netting that will provide excellent protection from these pests.
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Diseases of Apple and Pear
Diseases in common = Fire blight, Scab*, Sooty mold and Fly speck = Scab of apple caused by Venturia inaequalis: Scab of pear caused by V. pirina Discussion: In Oklahoma apples are attacked by more diseases than pear. However, both are susceptible to diseases that can result in serious damage to the either the tree or the fruit. The diseases listed on this slide are ones that attack both apple and pear. Both apple and pear have a disease named scab, but it is not caused by the same pathogen.
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Fire Blight Erwinia amylovora Apple and Pear
Bacterial disease Initial infections occur during bloom when rain or hail occur Symptoms: Infected tissues wilt, turn brown to dark brown Infected terminals wilt from the tip, often develop a crook at the growing point Inset picture: Apple branch expressing typical symptoms of fire blight. Discussion: Fire blight, caused by the bacterium Erwinia amylovora, is the major disease problem faced by pear growers. It is also a problem on susceptible apple varieties. Fire blight causes loss of blossoms and fruit, but its most serious effect is reduced future production due to destruction of fruiting wood.
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Fire Blight Erwinia amylovora Apple and Pear
Infections spread rapidly Significant damage in one growing season Control: Resistant varieties Golden delicious Jono McLemore Sanitation Spray during bloom antibiotic or copper Inset picture: Containers of the bactericide streptomycin sulfate. Discussion: Many practices help reduce the severity of fire blight. Not all measures are necessary or feasible in every planting. On susceptible varieties no single control method is adequate and the disease must be made to control the disease each year. Cultural practices such as planting on well-drained soil and applying nitrogen fertilizer early will help to prevent infections of fire blight. Applying to much nitrogen or applying nitrogen to late will increase the incidence of fire blight. Spraying a bactericide during bloom, beginning at 10% bloom and continuing on a three day schedule through petal fall will help to control fire blight. Streptomycin sulfate is the recommended bactericide. It is sold under many different trade names. Streptomycin sulfate is an antibiotic. Repeated applications of an antibiotic does have some disadvantages and some plant pathologists are opposed to routinely using an antibiotic to control a plant disease. This opposition is due to the fact that bacteria often develop resistance when repeatedly exposed to an antibiotic. Refer to OSU Fact Sheet #7615 “Fire Blight of Fruit Trees and Certain Ornamentals” for more information on fire blight.
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Cedar-apple Rust Cedar Gymnosporangium juniperi-virginianae
Cedar-apple rust gall Fall of 2nd year on cedar Somewhat kidney shaped Chocolate brown with small circular depressions Inset pictures: Top - cedar-apple rust gall on cedar tree prior to development of the telial horns. Bottom - gall on cedar in early spring with developing telial horns Discussion: Cedars growing in close proximity to apple trees susceptible to cedar-apple rust are going to greatly increase the amount of infection on both the apple and cedar trees. Cedar-apple rust can be controlled on cedar by spraying a fungicide during July and August. In some cases if only a few galls exist on the cedar tree, they can be pruned out. It should be pointed out that the large gall doesn’t appear on the cedar tree until the second year after infection. Therefore, if a homeowner begins spraying his/her cedar tree, the first spring following the initiation of the spray program the number of galls will not be reduced. However if the spray program on the cedar is continued the second spring following the initiation of foliar fungicide applications on the cedar should bring a reduction in the number of galls on the cedar tree.
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Cedar-apple Rust Apple Gymnosporangium juniperi-virginianae
Foliar symptoms Initially appear as small greenish-yellow spots Enlarge becoming orange-yellow surrounded by red margin Inset picture: Top and bottom side of apple leaves infected with cedar-apple rust Discussion: The bright colors of the lesions produced by this disease make it easy to identify. Small, pale yellow spots develop on the upper leaf surface shortly after bloom. These spots gradually enlarge and turn orange.
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Cedar-apple Rust Apple Gymnosporangium juniperi-virginianae
Control Resistant Varieties: Dayton Delicious Williams’s Pride Fungicide applications Begin at bloom and continue on 7-day schedule until galls on cedars dry up Inset picture: Apple fruit with cedar-apple rust lesion Discussion: Fruit infection is most common near the bloom end (calyx end). Lesions are similar in color to those on leaves except the border is a darker green than normal. Control can be obtained by removing cedars within a two-mile radius but this is not a practical method. Some varieties are resistant to cedar-apple rust. The varieties listed on the slide are resistant to cedar-apple rust but the variety Dayton is not widely available and may not perform well under Oklahoma conditions. Delicious and Williams Pride are both variety recommended for eastern Oklahoma. When growing varieties that are susceptible to cedar-apple rust and where this disease has been a historical problem fungicides can be applied to prevent the disease. There are several fungicides that are highly effective in preventing cedar-apple rust infections. They should be applied beginning at bloom through the third cover spray. Refer to OSU Fact Sheet #7611 “Cedar Apple Rust”.
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Fly speck and Sooty mold Mycrothyriella rubi and Gloeodes pomigena Apple and Pear
Both are superficial Minimal damage lower quality lower market value Fly speck = sharply defined, shiny black dots in groups of a few to 100+ Sooty mold = sooty or cloudy blotches that are brown to olive green with indefinite outlines Inset picture: Apple infected with both fly speck and sooty mold. The fly speck appears as small dark dots in the center area of the apple, and the sooty mold is visible as a solid dark, moldy area on the upper portion of the apple. Discussion: Fly speck and sooty mold are common names of two diseases usually found on apple and pear fruit at the same time. They are caused by different fungi. They do little, if any, actual damage to the fruit but lower the market value by the presence on the surface.
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Scab Venturia inaequalis and V. pirina Apple and Pear
Symptoms similar on apple and pear Occurs on leaves and fruit Leaves develop velvety brown to olive spots, turn black with age, distorted Fruit infections appear similar to leaf infections, with age - turn brown and corky Inset picture: Top - scab lesions on an apple leaf; bottom - scab lesions on apple fruit. Discussion: Apple scab occurs in most areas where apples are grown and can be a problem on apples grown in Oklahoma. It is less severe in dryer climates. Fortunately, successful control procedures have been developed and losses from scab can be prevented. Pear scab is caused by a fungus in the same genus but a different species than the one that causes apple scab. Pear scab occurs occasionally on Bartlett pears, but is more likely to be a problem in backyard plantings of little known or exotic pear varieties.
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Black Rot Apple Physalospora obtusa
Symptoms on fruit: Mature lesion exhibits a series of concentric rings alternating from black to brown. Rotted area remains firm and is not sunken Inset picture: Apple fruit infected with black rot Discussion: There are several different fruit rots that occur on apples, including black rot, white rot, and bitter rot. All these rots are caused by different fungi and produce different symptoms on the apple fruit. Black rot is probably the most common but the other rots are often observed on backyard fruit trees. Backyard growers can expect to see fruit rots if they do not take actions to prevent infections. Infected fruit develop a brown to black rot with alternating light and dark bands around the blossom end of the fruit or in an injured area on the fruit. The rotted tissue remains firm.
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Black Rot Apple Physalospora obtusa
Mature black rot canker Typically reddish brown and slightly sunken Can become several feet in length Weakened branches break under heavy crop load Inset picture: Mature black rot canker on an apple branch Discussion: Black rot also infects branches and limbs. It causes cankers on branches weakened by heavy shading, sun scald, or winter injury. Pruning cuts and old fire blight cankers are major point of entry. The limb cankers are most often found on older trees; young, non-bearing trees are rarely troubled by this disease.
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Bitter Rot Apple Glomerella cingulata
Symptoms vary from small, slightly sunken areas to large, dark brown areas with yellow margin Internally, lesions extend in a cone shape towards the core Control: Same fungicides and same spray schedule as Black rot Inset picture: Apple fruit infected with bitter rot Discussion: This disease is occasionally severe on apple trees where temperatures are high enough to favor disease development. This is a disease of the fruit and does not infect woody parts of the tree. Fruit lesions can appear beginning when the fruit is about half grown. The lesions are slightly sunken, circular and brown.
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Powdery Mildew Podosphaera leucotrica Apple
On leaves: whitish, felt-like patches of moldy growth Infected leaves: narrower than normal, become stiff and brittle Fruit: russeted and small (Jonathan most susceptible) Inset pictures: Left - Close-up of powdery mildew symptoms on apple leaf; middle - leaves curled by powdery mildew infection; right - fruit russeted by powdery mildew Discussion: Powdery mildew is caused by a fungus and is often an important disease on backyard apple trees. Losses result from (1) death of vegetative shoots; (2) death of flower buds resulting in yield reduction; (3) loss of fruit quality due to russeting. It is most destructive on highly susceptible varieties, but after it has built up to high levels, it may affect adjacent, moderately resistant varieties. Refer to OSU Fact Sheet #7617 “Powdery Mildews of Ornamentals and Fruit, Shade and Nut Trees” for more information on powdery mildew.
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Control of Apple Diseases
Spray schedule Green tip to 1/2 inch green leaf - Cedar-apple rust *, Scab, Powdery mildew, Bitter rot, Black rot Pre-bloom - Cedar-apple rust , Scab, Powdery mildew, Bitter rot, Black rot Bloom - Scab, Fire blight * Petal fall - Scab, Powdery mildew, Bitter rot, Black rot Early cover - Scab, Powdery mildew, Bitter rot, Black rot Summer cover - Scab, Powdery mildew, Bitter rot, Black rot Most varieties recommended for Oklahoma are susceptible fire blight Discussion: Backyard fruit producers will often save themselves some frustrations if they plant apple varieties resistant to fire blight. There are some varieties recommended for Oklahoma that are moderately resistant to fire blight. Refer to the Study Guide for varieties that are fire blight resistant. In most situations, to grow diseases-free apples, a fungicides are going to have to be applied. However, there are situations where this may not be true. If the apple trees are isolated and have a history of being disease free, then fungicides are not going to be required. Most people are not this lucky. Following the spray schedule shown on the slide will insure high quality, disease free fruit. Eliminating sprays or extending the time between cover sprays from 7 to 14, to 14 to 21 days will often result in increased disease. The home owner will have to decide how closely they want to follow the spray schedule and what fruit quality they want in their backyard apples. It is recommended that if a backyard fruit grower is going to apply only two or three fungicide applications that they not spray at all. They either need to commit to applying several fungicide applications or none at all.
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Apple and Pear Insects Codling moth Up to 3 gen/yr Larvae Adult Damage
Petal fall Cover sprays 10 Day intervals Inset pictures: Top left - codling moth larva; top right - adult codling moth; lower left - fruit showing codling moth damage Discussion: Codling moths attack apples and pears and some stone fruits. The codling moth causes two types of injury: deep entries and stings. Deep entries occur when larvae tunnel into fruit from the side or calyx end and remain in the fruit. Stings occur when the larvae die before gaining entry. Warm, dry conditions favor the development and injury from larvae in the fruit. First moths of the season appear as the last petals fall from the tree. The adult moth is 3/8 inch long and grayish in color. Moths hold their wings tent-shaped over the body when resting. Eggs are laid on the fruit or nearby leaves. Eggs hatch in 6-14 days and feed for 3 weeks in the fruit. The larvae is cream to pinkish in color with a brown head . They reach a length of to inch. Second brood moths lay eggs for about 2 months. Three generations can occur but the 3rd is usually a “suicide brood”. The larvae that do not pupate will overwinter and start the cycle next spring. Control of codling moths is achieved by spraying with a recommended insecticide at petal fall and with cover sprays every 10 days to prevent injury. Homeowners may wrap corrugated bands of cardboard around the tree trunk in spring, remove in September and burn. This will eliminate the overwintering cocoons.
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Apple and Pear Insects Plum curculio Adult Larva Seldom form in fruit
Egg Scars Petal fall Cover sprays Pick up fallen fruit Inset picture: Top left - adult plum curculio; top right - plum curculio larva; middle typical curculio feeding scar on fruit; lower left - curculio damage on young apple fruit; lower right - curculio damage and signs on fruit nearing maturity. Discussion: The plum curculio is one of the most important insects attacking tree fruits. It attacks stone fruits as well as apple. The damage caused by this pest includes: crescent-shaped scars, internal injury by larvae, premature dropping of fruit, and feeding punctures in the fall. These snout beetles migrate from woodlots for periods of up to 6 weeks after bloom with the greatest migration occurring within a 14 day period after petal fall. After larvae feed and pupation occurs, the plum curculio adult emerges and feeds before cold weather forces them into hibernation quarters. This pest can be difficult to control and needs a full dosage of an effective pesticide. Adult plum curculio are dark brown beetles about 3/16 inch long with whitish to gray patches and has three pairs of humps on its wing covers. The beak or snout is about as long as the body length. The larvae are yellowish white with a well-defined brown head capsule and no legs. A fully developed larva is about inch in length. In apples, the larvae seldom develop in the fruit. However, they develop well in the stone fruits. In apples, fruit drop is common and picking up fallen fruit helps control this pest. Limb jarring on dropcloths and removal of adult weevils can aid in control. Chemical control should begin at petal fall and continue through the growing season when this method of control is chosen over the alternative methods.
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Apple and Pear Insects Cankerworms Larva Injury Prebloom
Superior summer spray oil Insect pictures: Upper right corner- canker worm adult moth; upper left - canker worm egg mass; mid-right -canker worm larva; lower left - canker worm damage on young apple Discussion: Cankerworms are unique in the fact that males are gray moths with faint black and white markings while the females are wingless. Male moths have a wingspan of 1 to 1 inches. Larvae are sometimes referred to as “measuring worms”. The worms have true legs (segmented) on the forward part of the body and prolegs on only the two or three posterior segments. They reach about 1 inch when fully developed. Cankerworms range in color from light yellow-brown to a dull black. The larvae often mimic twigs by extending its body from a twig holding by its prolegs. Eggs are laid on branches and twigs and the larvae feed on leaves for about 3-4 weeks, drop to the ground, and pupate. They overwinter as eggs or pupae. One generation per year occurs for the spring cankerworm and the adult moth is found from February through April. Damage consists of defoliation and weakening of the tree, particularly young trees. Because of their close association with the plant and their overwintering habits, oils are a good choice for controlling this pest. Superior summer spray oil is especially effective since the females are wingless. Another method of control is the use of barriers such as tanglefoot, a sticky material placed around the trunk in a band to prevent the wingless female from climbing up the trunk. The biological insecticides are also a good choice for this pest when applied in April and May.
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Apple and Pear Insects Aphids Adults and nymphs Dwarfing and honeydew
Smut Dormant spray Prebloom with superior summer spray oil Problem increases with cover sprays Inset pictures: Top left - close-up of aphids; middle - honey dew on leaves and small apple fruit; bottom - sooty mold or smut development on apple fruit as result of honey dew Discussion: Aphid infestations can become serious with high populations. These tiny insects, often called plant lice, are generally found on the lower sides of leaves. Many species of aphids can and do attack fruit crops. Color varies with species and ranges from pale yellow to dark green to reddish brown to purple. With large numbers, dwarfing of the plant and honeydew accumulations oftentimes result in smut formation. Light infestations can be tolerated and in fact may contribute to the beneficial population. Chemical selection is important in aphid control. Avoid using carbaryl early in the season which contributes to aphid outbreaks. A dormant spray will deter or limit aphid buildup in the early season. A prebloom spray with a superior summer spray oil also limits this pest. Cover sprays should keep numbers of aphids at an acceptable level during the remainder of the growing season. Alternative methods of control include: rubbing the leaves between thumb and forefinger, insecticidal soaps, strong streams of water, and interplantings of aromatic plants such as garlic, chives, petunia, and anise.
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Apple and Pear Insects Mites Adults and eggs Overwintering Eggs
Dormant spray Prebloom with superior summer spray oil Compounded by hot dry weather Inset pictures: Top - close-up of adult red spider mites; middle - adult mites with webbing; bottom - mite eggs. Discussion: This minute pest is a globular shaped eight legged arthropod in the adult stage and is only about 1/64 inch long. It causes damage by inserting its mouthparts and removing cell contents including chlorophyll. This feeding results in a ‘bronzing’ effect when mite numbers become high. Webbing from mite infestations becomes apparent when mites are prevalent. Mite infestations can explode. It has been estimated that a single pair of mites could produce 227,812,500 progeny by the end of a growing season. Mites overwinter on the tree. Therefore, they are susceptible to dormant sprays. Egg mortality is adversely affected by extremely cold winter weather. Hot, dry weather favors mite buildup during the summer months and a miticide such as Kelthane may be necessary if injurious numbers occur. Organic methods recommended by gardeners include: hosing off plants with a pressurized spray to wash away mites and break up the webs, and using a sticky slurry of flour and buttermilk.
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Apple and Pear Insects Scale Short mobile period Feeds on sap
Males and crawlers Infested twig Most damage May kill young tree Infested fruit Dormant spray Inset pictures: Top - scale on apple twig; bottom - scale on apple fruit Discussion: Scale insects are especially damaging to young trees. They may actually kill larger trees over time. Scale insects have a tremendous reproductive potential. Therefore, entire trees can become covered. These sapfeeders weaken the host plant if left uncontrolled. Scale attacks the bark, twigs, leaves, and fruit. Many species of scale exist and they vary tremendously from one specie to another. Scale are often inconspicuous while others may be very visible. Color ranges from white to very dark. If in doubt, rub the suspected area and if the raised area dislodges as a crusty material, scale is most likely. Dormant sprays along with cover sprays should keep scale insects under control. Cover sprays usually control this pest.
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Apple and Pear Insects Leafrollers Adult Damage Larval stage
Feed on leaves and fruit Petal fall Cover sprays Inset pictures: Top - adult leafroller moth; middle - leafroller damage on apple fruit; bottom - larva of leafroller and damaged foliage. Discussion: Leafrollers are the immature stages of moths that are to 1 inch in length with wingspans of approximately to 1 inch depending upon species. Rather than describe the many different species, it is more important to recognize some generalities concerning leafrollers. Multiple generations occur for the various species and leafrollers attack both leaves and fruit. Damage to the leaves is usually insignificant but fruit can be damaged by the larvae of the first brood making small cavities in the fruit resulting in misshapen or deformed fruit. Due to the large number of plants attacked by leafrollers, spraying at petal fall and repeated cover sprays are often necessary to control this pest. Close observation under low pesticide usage is necessary to prevent unacceptable damage. If only a few leaves are involved, removal and destruction of plant material will aid in control. The biological insecticides should work well for controlling leafrollers.
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Stone Fruits Apricots Cherries Nectarines Peaches Plums
Inset picture: Composite of apricots, cherries, nectarines, peaches and plum Discussion: Nothing tastes better than fresh, tree-ripened peaches. The stone fruit group of trees begins to bear about two years earlier than pome fruits. The trees are also easier to prune and maintain than some other types of fruit.
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Stone Fruits Shorter lived, more pests, frost risk Bears in 3 years
Easy to train Fruit more perishable Inset picture : Peach tree in bloom Discussion: In general, stone fruits are more difficult to grow and produce than pome fruits. They are more sensitive to site selection, more prone to frost injury, have more disease and insect problems, and the fruit is more delicate to handle.
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Site Selection - Stone Fruits
Peach and nectarine - do not tolerate wet soil conditions Avoid site where water stands more than 1 week after heavy rains Avoid soils with high water tables Dig holes 4 feet deep - Fill with water If stands 24 hours = bad site Sandy soils - support peach trees May require supplemental irrigation Discussion: Close attention has to be paid to selecting sites for stone fruits. Peaches and nectarines will not tolerate wet soils so planting sites with clay type soils are virtually eliminated. An alternative is to berm soil up about eight inches high by three to four feet across and grow trees on a raised bed.
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Peach and Nectarine Rootstocks
‘Halford’ or ‘Lovell’ rootstocks survive in hot, humid Oklahoma soils Discussion: These time tested root stocks ensure a much longer life for peaches growing in Oklahoma.
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Peach and Nectarine Varieties
Resistance to bacterial spot Winter hardy and late blooming Cling vs. Freestone White flesh vs. Yellow flesh Span the season…..flowering time does not coincide with date of ripening. Choose early, mid- & late-season types. Discussion: Early blooming does not mean early fruit ripening. Flowering time does not coincide with date of ripening. Choose early, mid and late ripening varieties. Also choose varieties that bloom late to avoid spring frost and freeze damage. Chemical control for bacterial leaf spot is difficult, choose and grow only cultivars resistant to this disease. A nectarine is a fuzzless sport of a peach tree that has been improved upon over time. (Sport is a bud mutation.) Refer to OSU Fact Sheet #6210 “Apple and Peach Varieties for Oklahoma”
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Training Peaches and Nectarines
At planting…..cut 18” to 30” high Remove branches lower than 12 inches Train to open-center “vase” shape Select only 3 to 4 main scaffold limbs Prune heavily yearly Inset picture: Second year unpruned peach tree Discussion: Use the picture in the slide to point out three to four scaffold limbs and point out the center would be cut out after the 2nd year of growth. Peach trees are pruned heavily beginning very early in the life of the peach tree. This pruning is required in order to train the tree to the “open-center” system that is recommended for peaches growing in Oklahoma. Heavy annual pruning, removing about 1/3 of the branches will be required to maintain the “open-center” system and to ensure good repeat bloom and fruit set, while keeping trees stocky and strong.
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Pruning of Peaches and Nectarines
Remove up to 1/3 of wood/year Remove damaged limbs Remove suckers Remove water sprouts Maintain open center pruning system Inset picture: Upper right - 6 year old peach tree trained and pruned to the open-center system. Note the 3 to 5 main scaffold branches on each tree. Lower left - water sprouts that have to be pruned out whenever they occur. Discussion: Peaches and nectarines have a very different growth habit from the pome fruits. Flower buds for the next year are formed on new wood. The tree must continue producing new, young shoots in order for flower buds to continue to form. Peaches and nectarines need to be trained to an open center….like a wide bowl. Light must enter the center of the tree to allow new shoots with flower buds to form on an annual basis. Consequently about 30% of the growth is removed each year to both control height and keep the tree opened up to sunlight.
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Growing Peaches and Nectarines
Adhere to spray schedule Stay ahead of peach tree borer Apply nitrogen twice in spring and summer Thin fruit to one every 8 inches on limb before pit hardening Provide plenty of water Discussion: Trees need constant care to survive here. Frost and freeze protection is most critical as buds open in spring. At full bloom, and thereafter, buds are at high risk for freeze damage. To help prevent freeze damage, moisten soil under trees thoroughly the night of the freeze. This helps release heat from the ground. Small trees can be covered with a sheet or light tarp for frost protection. If a freeze threatens, consider some type of heat source beneath the covering such as a low-wattage outdoor light. Just enough heat to keep temperatures right at 32° or 33° F. can save a crop. Examine blossoms after a freeze to assess levels of damage. The stigma (female part in center of a peach flower) will be black if it’s been frozen. Young fruit that’s frozen will be black in the center if cut open and examined. Begin spraying for pests at 75% petal fall according to the OSU Home Fruit Spray Schedule. Heavy losses to “wormy” peaches can occur if trees are not protected. If peach tree borer is not prevented, most young trees only survive long enough to bear a few small crops before their vascular tissue is plugged by this pest. Peach trees are vigorous growers and need extra nitrogen twice during the growing season to ensure good bud set for next year’s crop. Watering is critical to grow full size peaches. Begin supplemental watering about 3 to 4 weeks before anticipated harvest time.
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Cherries Sweet Cherries ‘Bing’ types….grow well
Need 2nd variety for pollination Choose crack-resistant varieties Sour Cherries pie cherries... easy to grow, dwarf varieties available Both types have fewer pests Discussion: Birds are the number one problem with cherries. Grow dwarf types that are easy to cover with netting. Yellow-fruited varieties are less attractive to birds, however, people aren't attracted to them either. ‘North Star’ dwarf pie cherry is a good variety as it stays small enough to easily cover with netting. Cherries ripen in Oklahoma during the early summer when conditions are quite moist. As a result, cracking of fruit is a problem, especially with sweet cherries. Choose varieties listed as crack-resistant.
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Growing Good Cherries Select for disease and crack resistance
Select dwarf types so bird netting can be applied Be diligent about peach tree borer Train to vase shape…..little other pruning needed Discussion: Beyond a basic open-centered, vase shaped limb structure, cherries require little in the way of pruning. Annually remove the three D’s of pruning: dead, damaged or diseased wood and those limbs that are crossing and rubbing against another. Cherries have been grown successfully in the backyard with no sprays other than protection from peach tree borer and birds. They are the easiest of the stone fruits to grow in Oklahoma.
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Plums European or Prune-type: good for drying, canning and preserves
Japanese or Dessert-type: juicier, best for fresh eating Inset pictures: Left - European or Prune-type plums; right - Japanese or dessert-type plums. Discussion: Plums are more challenging to grow due to heavy insect pressure right after bloom. Oriental fruit moth and plum curculio are severe as well as several foliar feeding caterpillars and twig diseases. Also, they bloom early enough that spring frosts can kill the blossoms.
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Plum Varieties and Pollination
Rootstocks: Not as critical Select Varieties: Disease resistant Winter hardy Pollination: European will not cross pollinate Japanese Select two of both types to insure fruit set Discussion: To insure good pollination plant at least two trees of the type of plum that is to grown. Plums can be short-lived if spray schedules aren’t followed, especially for borer control.
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Plum Training and Care Train to vase shape
Avoid knicking limbs when pruning….makes entry point for disease Thin fruit to one every 3 to 4 inches Avoid over-watering near harvest Be diligent about peach tree borer Discussion: Points listed on slide are self explanatory.
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Apricots Choose cold hardy, late bloomers Select dwarf types
Grow in container = mobile tree = frost protection Thin fruit to one every 3 to 4 inches Protect from birds Be diligent about peach tree borer Inset picture: Apricot fruit Discussion: One of, if not, the most challenging stone fruit to produce in Oklahoma . However, the rewards of fine, ripe apricots are worth the effort. Frost usually prevents fruit production on Oklahoma apricots, however an apricot tree can be protected from frost by making it mobile. This is accomplished by growing the tree in a large pot and moving it indoors until the danger of spring frosts has passed. Then the tree can be moved outside until the first killing frost of the fall.
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Diseases of Stone Fruits
Apricots Cherries Nectarines Peaches Plums Discussion: Of the fruit crops grown in Oklahoma, stone fruits have the most disease problems. There are many diseases of stone fruits and only a few are included in this program. In order to be successful at growing and producing stone fruits a homeowner must be dedicated to the efforts to prevent diseases as well as insects.
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Peach Leaf Curl Taphrina deformans Peach and Nectarine
Leaves severely deformed Color varies from light green to purple Infection requires free moisture, active leaf buds, and temperature between 50° and 70° F Control requires dormant season fungicide application Inset pictures: Top - cluster of peach leaves infected with peach leaf curl and expressing typical symptoms of the disease; bottom - close-up of a peach leaf expressing the purpling and puckering of tissues infected with the peach leaf curl pathogen. Discussion: Peach leaf curl is a fungal disease that, under the right environmental conditions can cause severe early defoliation. It requires a specific set of environmental conditions for peach leaf curl to develop. The leaf buds have to be opening, free moisture in the form of rain, or heavy dew must be present, and the temperature has to be between 50° and 70° F or the disease does not develop. Therefore the disease occurs some years and not others depending entirely on the environment. Application of late dormant season fungicides is required to control leaf curl. Fungicide applications after symptoms appear are of no benefit. Refer to OSU Fact Sheet #7639 “Leaf Curl of Peaches and Nectarines” for more information on this disease.
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Bacterial Spot Xanthomonas campestris pv
Bacterial Spot Xanthomonas campestris pv. pruni Peach, Nectarine, Apricot, Plum Infects leaves, fruit and young twigs Foliar lesions angular brown to black and fall out = shot hole Causes defoliation Fruit lesions occur randomly over the fruit, circular to elongate and rough Inset pictures: Upper left - close-up of peach leaf expressing shot hole symptom of bacterial spot; upper right - peach leaf expressing foliar lesions prior to tissue falling out; bottom - peach fruit with bacterial spot lesion. Discussion: Bacterial spot is a serious and frustrating disease for all peach growers, backyard and commercial. The reason is that it is very difficult to control and can cause severe problems on the foliage and fruit. Under favorable environmental conditions this disease can cause severe defoliation of susceptible varieties and significantly reduce the quality of the fruit. Backyard peach growers should try to select varieties that are resistant to bacterial spot. Refer to OSU Fact Sheet #6210 “Apple and Peach Varieties for Oklahoma” for variety reaction to bacterial spot.
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Scab Xanthomonas campestris pv. pruni Peach, Apricot and Nectarine
Most important as fruit infection Start as small greenish spots, enlarge to 1/4 inch diameter Develop dusty green to black appearance Lesions typically clustered near the stem end of fruit Easily confused with Bacterial spot Inset pictures: Upper and lower pictures both showing fruit with scab lesions. Note how the lesions are clustered near the stem end of the fruit. Discussion: Scab is a common disease on peaches grown in Oklahoma. The fruit lesions are often easily confused with bacterial spot, but taking into consideration where the lesions develop on the fruit (scab lesions cluster near stem end of fruit) and if foliar lesions and defoliation occurred (both associated with Bacterial spot infections) can help determine if the disease is scab. Unlike Bacterial spot, scab can be easily controlled with the repeated application of recommended fungicides. Trees with past history of scab should be treated with fungicides to prevent this disease causing problems on the fruit. Refer to OSU Fact Sheet #7641 “Common Diseases of Stone Fruit Trees and Their Control” for more information on scab.
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Brown Rot Monilinia fructicola Peach, Nectarine, Apricot, Cherry, Plum
Infects immature or mature fruit Soft dry rot Rapidly spreading on fruit (48 hrs) Infected fruit sporulate profusely, shrivel = mummies Inset pictures: Left - brown rot on cherry fruit; middle - brown rot on nectarine; right - brown rot mummy on peach tree. Discussion: Brown rot is a common and devastating disease of peach, nectarine, apricot, plum and cherry. It reduces yields by rotting the fruit both on the tree and after harvest. In seasons when environmental conditions are unusually favorable for infection, entire crops may be lost, almost overnight. Brown rot is recognized by the ash-gray tufts of fungal growth that develops over the surface of the fruit lesions. Brown rot is also capable of infecting and killing blossoms and shoots but these phases of the disease do not occur on a regular basis in Oklahoma. Refer to OSU Fact Sheet #7641 “Common Diseases of Stone Fruit Trees and Their Control” for more information on brown rot.
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Black Knot Dibotryon morbosum Plum and Cherries
Elongated, corky swellings or knots on limbs New knots greenish and soft, become hard and black Causes dieback of infected limbs and stunting of growth above the knots Plant black knot resistant cultivars Prune out infections Apply fungicides Inset pictures: Upper left - young black knot galls on plum; lower right - mature black knot galls on plum. Discussion: Black knot is a serious and widespread disease of plums and cherries. It often becomes a serious problem in home orchards where pruning and spraying are not regularly practiced. The disease becomes progressively worse during each growing season and unless effective control measures are taken, it can stunt or kill the tree. It can also infect apricots, peaches and nectarines but is much more common on plum and cherries. Fungicides can provide protection but are unlikely to be successful if sanitation and pruning are ignored. In situations where black knot has been a problem, fungicides need to be applied from bud break to early summer.
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Control of Stone Fruit Diseases
Plant peach varieties tolerant to bacterial spot (Redskin, Redhaven, Candor, Dixired, Sunhaven) Apply fungicides: Dormant season - Peach leaf curl, Bacterial spot, Black knot Shuck split - Brown rot, Scab, Black knot Cover sprays - Brown rot, Scab, Black knot Apply cover sprays at 10- to 14-day intervals Discussion: Diseases can make producing quality fruit from stone fruit crops difficult. One of the first steps is to try and select a variety that is resistant to bacterial spot. This disease is difficult to control with chemicals and can lead to frustration if a bacterial susceptible variety is grown. Initially a gardener may be able to forego a fungicide spray program, but odds are that over time disease will become established and cause infection levels to be so high that fungicides will have to be applied in order to obtain any edible fruit. Often a 7- to 10-day fungicide spray schedule will have to be followed in order to obtain good production. In most cases, fungicides and insecticides can be tank mixed and sprayed together.
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Insects of Stone Fruits
Oriental fruit moth 3 Gen/yr Adult and pupa Larvae Damaged shoot Infested peaches Petal fall Shuck split Cover sprays Inset pictures: Top left - oriental fruit moth adult and pupa; upper right - oriental fruit moth larva; middle - oriental fruit moth damage on peach twig; middle left and bottom - oriental fruit moth damage to peach fruit. Discussion: The adult Oriental fruit moth is a small, grayish, mottled moth about 1/4 inch long, with a wingspan of about 1/2 inch. Wings are held rooflike over its body when at rest. Newly hatched larvae are 1/16 inch long and are cream colored with a black head. Older larvae have a brown head capsule and are slightly pink in color. Larvae have three pairs of true legs, and four pairs of prolegs located on the third, fourth , fifth, and sixth abdominal segments. The Oriental fruit moth attacks a wide range of fruits and is found in all areas where stone fruits are grown. The larvae attack twigs and fruits. “Dying-back” of new growth is a good indication that Oriental fruit moth is present. During May, June and July when terminal growth is rapid, twigs are especially attractive to this pest. Young trees are usually most susceptible to attack. One larva may enter 2-5 twigs and a developing fruit. Fruit injury consists of “old injury”, which refers to damage caused early in the season when larvae leave twigs and enter fruit usually from the side where leaves or fruit are touching. “New injury” refers to fruit that is almost fully grown and larvae go directly to the fruit entering at the stem with no visible evidence of entry on the outside. Three generations of Oriental fruit moth occur in the Midwest. Insecticide applications at petal fall, shuck split and additional cover sprays should protect fruit from Oriental fruit moth. The third generation is the one most responsible for wormy fruit. Spraying days prior to harvest should minimize wormy peaches. Homeowners should grow early-ripening varieties if they want to minimize the use of insecticides for Oriental fruit moth control. As with other fruit inhabiting pests, picking up fallen fruit and clean cultivation will reduce the incidence of Oriental fruit moth.
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Insects of Stone Fruits
Plum curculio Shuck injury Larvae develop well Adult Petal fall Shuck split First and second cover sprays “Wormy peaches” Inset pictures: Top - curculio injury to a peach shuck (base of flower); middle - adult plum curculio; bottom - plum curculio larva inside peach fruit. Discussion: Plum curculio attack the fruit soon after it forms. They eat holes through the skin and feed on the pulp, usually next to the pit. The larvae develop well in the stone fruits as opposed to their poor development in apples and pears. Plum curculio have no legs while the Oriental fruit moth have 3 pair of true legs and 5 pair of prolegs on the abdominal segments. Many “wormy peaches” are actually infested with curculio. Depending upon the fruit attacked and the variety, the fruit will either prematurely drop or have larvae next to the pit at harvest. Control consists of spraying at petal fall and at the shuck-split stages to minimize shuck injury and again during first and second cover sprays for good control. This pest has become perhaps the most damaging pest of developing stone fruits. Removal of fallen fruit and limb jarring to collect adult weevils on drop cloths are some non-chemical methods of control for this pest.
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Insects of Stone Fruits
Catfacing insects Plantbugs Stinkbugs Damage Pre-bloom Petal fall Shuck-split Cover sprays Inset pictures; Top - green stinkbug nymph; middle - adult green stinkbug; bottom - catface damage on peach. Discussion: Plant bugs and green stink bugs damage stone fruits by injuring blossoms, causing fruit drop, catfacing injury and gummosis. Plant bugs typically attack early, causing blossom damage and cat-facing. Generally their numbers decrease over the season. Frequently green stink bugs appear late in the season migrating from woodlots and borders. Insecticidal sprays at pre-bloom, petal fall, shuck- split, and additional cover sprays are sometimes needed to control this troublesome group of pests. Clean cultivation will minimize problems associated with plantbugs.
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Insects of Stone Fruits
Scale Infested limb Crawlers Dormant spray Removes sap Reduces vigor Loss of trees Inset pictures: Top - scale infested limb; middle left and right - close-up of crawler stage; bottom - close-up on mature scale. Discussion: Stone fruits are subject to attack from scale insects. Similar damage occurs on stone fruits as discussed for apple and pears. The scale feed on sap and reduce the vigor of the tree. Fruit size may be reduced and premature drop is likely to occur. Many times twigs and branches will die. Neglected trees can actually be killed by scale insects because of their tremendous reproductive potential. Dormant sprays will keep scale insects under control and if outbreaks occur during the growing season, a well-timed spray will control crawlers.
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Insects of Stone Fruits
Lesser peach tree borer Adult Infested limb Damage scaffold limbs and branches Gum mixed with wood borings or sawdust-like frass Prebloom and cover sprays Inset pictures: Top - adult lesser peach tree borer moth; bottom - lesser peach tree borer infested limb showing gumosis and sawdust associated with the borer infestation. Discussion: Lesser peach tree borers differ from the peach tree borer in that the moths emerge over a long time during the summer months. Also, the larvae are not confined to the trunk, instead they can be found in the trunk, scaffold limbs and branches. Larvae are found under the bark in wounded or injured portions of the tree. Pruning wounds, winter-injured areas, or diseased areas of the limbs are where they are commonly found. It cannot establish itself in healthy tissue. Canker fungus and lesser peach tree borers seem to complement one another. The presence of borers is revealed by sap flowing from wounded area, which contains brown frass from the larvae. Lesser peach tree borer adults are 1/2 inch long, clear-winged moths that resemble wasps. The wingspan is 5/8 to 1 inch. The male and female are metallic blue-black with pale yellow bands. The mature larvae are 3/4 to 1 inch in length. They have a yellowish-brown head and creamy white body. Spraying at prebloom and scheduled cover sprays should afford protection from this pest. Additionally, any practice that will reduce damage to healthy tissue will keep this pest under control.
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Insects of Stone Fruits
Peach tree borer Most serious threat Adult female Larval instars Borer in trunk Trunk treatment with recommended insecticides Pdb crystals - October Inset pictures: Top - adult peach tree borer moth; middle - base of peach tree with gumosis and discoloration associated with peach tree borer infestation; bottom - peach tree borer larva. Discussion: More stone fruit trees are killed by peach tree borers than any other causal agent. Control programs for peach tree borer must begin the year young trees are planted and must continue for the life of the planting. Either implement a borer control program or prepare for tree removal. Borer feeding destroys the vascular system resulting in the death of the tree. The peach tree borer overwinters as larvae on or under the bark of trees, usually below the ground level. Activity and feeding begin when soil temp reaches 50° F. The mature larval stage is 1 inch or greater in length and is cream to dirty white with a yellowish-brown to dark brown head. Upon emergence, females lay between 200 and 600 eggs during the 6-7 days she is alive. The adult female is recognized by being larger than the male and possessing a broad orange band on the fourth and fifth abdominal segments. The males and females are clear-winged, metallic, blue-black moths that resemble wasps. The wingspan is 3/4 to 1 1/4 inches. Damage can be recognized by masses of gum that contain small brown particles of bark at the base of the tree, or the occurrence of frass and empty pupal cases protruding from tree wounds. Borers can be found and removed with a knife or flexible wire to probe the larva from the trunk. Avoid mechanical injuries to the trunk which attract borers. Weedeaters are a contributing factor in many home fruit plantings. Control consists of one application of Lorsban in mid-May and with Thiodan once post-harvest during the first week of September. If a borer spray program is not followed then PDB crystals applied in October will kill the peach tree borer. Refer to OSU Fact Sheet # 6235 “Home Fruit Spray Schedule”, for detailed instructions on borer control.
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Insects of Stone Fruits
Beetles Green June beetles Japanese beetles Cover Preharvest Foliage feeders Ripe fruit Inset pictures: Top - green June beetle; bottom - Japanese beetle Discussion: Beetles can defoliate trees and be especially troublesome when fruit ripens. Japanese beetles are beginning to appear with greater frequency and they can defoliate trees if they go unnoticed. Green June beetles attack a wide range of ripening fruits and other crops and it is frequently necessary to apply an insecticide near harvest time. It is especially important to select an insecticide with a short “days to harvest” interval under these conditions. Japanese beetles are 3/8 to 1/2 inch long and have a metallic green head, thorax and abdomen, and coppery brown wing covers. Tufts of white hairs are located along the sides and just behind the tips of the wing covers. The average length of an adult beetle is 1/2 inch. Green June beetles are dull velvety green above with deep yellow to bronze margins, and metallic green below. They are about 1 inch long, 1/2 inch wide and flat on top. The larvae of both species are grubs that overwinter in the soil about 1 foot deep feeding on plant matter and roots.
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How to Harvest and Store Stone Fruits
Cherries Peaches and Nectarines Plum Apricots Inset slides: Top - plums; middle - cherries; bottom - peaches Discussion: No stone fruits truly ripen once removed from the tree. They may become softer, and can certainly rot, but they don’t continue ripening as do apples or pears. Leave fruit on the tree just as long as possible. Handle gently by removing from tree with a slight upward twist. Cool down immediately…especially peaches and nectarines. Store at 33° F and high (99%) humidity , if possible. They’ll keep about two weeks under these conditions. If not, can or freeze just as soon as possible. Stone fruits also dry very successfully.
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Pest Free Fruit Trees Oriental Persimmon Jujube Paw Paw
Crab Apples (disease resistant var.) Figs Mulberry Discussion: There are some nontraditional fruit trees that will grow and produce well in Oklahoma that are free of serious disease and insect pests. Several of these trees also make nice additions to the landscape, i.e. Oriental persimmon, jujube, crab apples and figs. Most, if not all, produce fruit that are good fresh or can be used to make jellies. The mulberry produces an abundance of fruit most years but the fruit is messy and thought needs to be given as to where this tree is planted.
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SMALL FRUITS Inset picture: Mosaic of fruit of blackberry, blueberry, grapes, raspberry, and strawberry.
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Grapes Inset picture: Cluster of Oklahoma grown grapes (variety unknown). Discussion: Grapes are popular for “Backyard” plantings because they can be used in many ways (jelly, wine, fresh table fruit). They can enhance the aesthetics of the landscape and they are adapted thoughout Oklahoma. However, grapes do have some major problems with insects and diseases. In order to have success growing grapes, the proper varieties and types need to be selected for the site in which the grapes will be grown. Grapes do not tolerate “wet feet”. Therefore the site selected for growing grapes must be well drained. Grapes will grow and produce on a wide variety of soil types but prefer sandy loam or loam soils that are deep and friable, contain an abundance of organic matter, and are somewhat acidic. Refer to OSU Fact Sheet # F-6246 “Growing Grapes in the Home Garden” for more information on site selection for grapes.
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Grape Types American bunch Muscadine
Discussion: American bunch grapes were derived primarily from wild grapes native to North America Muscadine are also native to North America, specifically the Southeastern United States. Southeastern Oklahoma is well adapted for producing Muscadine grapes. They do not produce grapes in tight clusters like bunch grapes.
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American Bunch Grape Derived from native grape species + some mixture of European species Popular home grown fruit Utilized as fresh fruit, wine, juice, jams and jellies Some problems with disease and insects Inset picture: Cluster of Oklahoma grown American bunch grape (variety unknown). Discussion: American bunch grapes are native to the United States and are a popular plant for backyard fruit plantings. Not only can a gardener be rewarded with a tasty and useful fruit, but the grape vine itself can be an addition to the landscape. Bunch grapes can be used to make any of the products associated with grapes, but if a grower wants to make wine for example, he/she must select a variety that will produce the taste and “dryness” that they prefer. Same is true for taste associated with “table” grapes. Different varieties produce different tasting fruit. Although grapes are well adapted to Oklahoma’s environment they do suffer from some significant disease and insect problems. A gardener needs to know this before starting to grow grapes. In most cases grapes require the use of pesticide application to prevent diseases and insects from destroying the fruit.
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BUNCH GRAPE VARIETIES Produce about 8 lbs. per vine
Table, wine, juice, or jelly Red, white, or blue Seed or seedless Harvest date Inset picture: Cluster of Oklahoma grown American bunch grapes (variety unknown). Discussion: Bunch grapes have the potential to grow and produce well in Oklahoma. The “Bunch grape” is diverse in its uses, color and seed production. It can add a great deal to a “Backyard Fruit Orchard” and be rewarding to a gardener who enjoys diversification. Refer to OSU Extension Fact Sheets #6222 “Home Fruit Planting Guide” and #6246 “Growing Grapes in the Home Garden”.
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Varieties of American-bunch
Mars** Early Blue Table Reliance*** Early Red Table Saturn* Middle Red Table Venus* Very Early Blue Table Concord - NOT RECOMMENDED FOR OKLAHOMA Winter Hardiness: * = Fair; ** = Medium; *** = Good Discussion: There are many varieties of bunch grapes that will grow and produce well in Oklahoma. However, Concord is not one of them. Oklahoma heat, especially the warm night temperatures, causes Concord to ripen unevenly, therefore it is not a recommend variety. The varieties listed on this slide are only four of many varieties that will produce well under Oklahoma growing conditions. The ones listed are all “Table” grapes, however there are varieties whose principle use is for wine making that will grow in Oklahoma. Refer to OSU Fact Sheet #6246 “Growing Grapes in the Home Garden” for a list of other varieties recommended for Oklahoma.
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Muscadine Grape Native to S.E. USA Adapted to moderate climate (10° F)
Insect and disease tolerant Popular for wine, pies and jellies Average vine = 35 lbs. of grapes Inset picture: Muscadine grape foliage and fruit. Discussion: Muscadines grow well where temperatures seldom fall below 10° F. Considerable injury generally occurs where temperatures fall below 0° F. Muscadines have a high degree of tolerance and/or immunity to pests and diseases that makes the production of bunch grapes difficult. They produce large quantities of fruit. Refer to the Study Guide for more information on Muscadine grapes.
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Muscadine Grapes Improved Varieties
Carlos - bronze Dixie Ree - red Doreen - bronze Magnolia - bronze Nesbitt - black Noble - black Regale - black Triumph - bronze Scuppernong and Thomas - old standards, not as good as improved varieties Discussion: Muscadines are not well adapted to northern Oklahoma because of the colder winters. However they will grow and do well in southern Oklahoma. Muscadines have fewer and less severe disease and insect problems than bunch grapes. Refer to OSU Fact Sheet #6246 “Growing Grapes in the Home Garden” for more information on muscadine grapes and also to the North Carolina Cooperative Extension Service Fact Sheet titled “Muscadine Grapes In The Home Garden” provided in the Study Guide.
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Planting February 1 to March 20 Purchase 1 year-old rooted vines
Plant vines 6 to 10 feet apart Plant with top of root ball even with surrounding soil Cut tops back, leaving only 2 or 3 buds Discussion: The ideal time to plant grapes, American bunch or Muscadine, is February 1 through March 20, however in the southeast one third of the state they can be planted in the fall from October to mid-November. Plants should not be set during dry windy conditions or if very cold temperatures are predicted. Plant bunch grapes 6 to 10 feet apart and muscadines 20 to 24 feet apart. Do not allow plants to dry out during the planting process. Do not plant to deep. Plant the top of the root ball even with surrounding soil. Cut the top of rooted settings back to 2 or 3 buds and keep the new plant well watered. Refer to OSU Fact Sheet # F-6246 “Growing Grapes in the Home Garden” for more information on planting grapes.
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Pruning Grapes February to early March
Discussion: Grapes are unusual among the fruits in that they thrive on what is considered severe pruning. It has been demonstrated that under good growth conditions maximum yields are obtained when about 90% of the previous season’s growth is removed during dormant pruning. Keep in mind that grapes produce fruit on the current season’s growth that originates from one-year-old spurs.
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Training and Pruning Young Grapes
1st year: Allow cane to develop Keep tied to stake or trellis wire Tip at top wire (4 to 5 ft) Prune all lateral branches Inset pictures: Left - line drawing illustrating a newly planted grape cane; right - line drawing showing early growth of newly planted grape. Discussion: During the first season the planted shoot (cane) is allowed to develop. It should be tied, with string, to a stake or trellis wire. Tip the cane to the desired height, usually 5 to 6 feet. During the first winter after planting, prune all lateral branches originating from the original cane to spurs containing two to three buds.
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Training and Pruning Young Grapes
2nd year Allow free growth of shoots from trunk and spurs Remove suckers from below bottom wire of trellis Remove flower cluster before bloom Winter - Begin training to the Kniffin system Select four canes and cut to five to eight buds Inset pictures: Left - line drawing illustrating second year growth of grape vine; right - line drawing illustrating how the grape should appear after pruning off the second year growth, which would occur in late winter prior to beginning of third year. Discussion: The second year is very important in developing and training the new grape vine. The vine is allowed to grow freely during the spring and summer with the exception of removing suckers that develop below the bottom wire of the trellis. During the winter, between the second and third growing season select four vigorous canes for the arms. Select canes that have grown along the wires of the trellis. Prune the four canes back to five to eight buds, lay them down along the wires, and tie them. Select four other canes, two near the upper wire and two near the lower wire, and cut them back to two or three buds in length for renewal spurs. Grapes vines that are three years or older, the main objective of pruning is to remove a majority of the old growth leaving desirable new canes from which next year’s fruiting growth will grow.
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Pruned Grape Vine Older vines - Every year, replace last season’s arms with canes that grew from last season’s renewal spurs and leave new renewal spurs Inset pictures: Left - line drawing illustrating a properly pruned older grape vine; right - photo of actual grape vine pruned as illustrated in line drawing. Discussion: The object of pruning is to adjust the amount of fruit that will be set by the plant to that amount that may be matured by the plant. As a rule, 40 to 60 buds will be sufficient for the production of a full crop on any grape vine. At the beginning of each year, the mature grape vine should look like it did at the beginning of the previous season. Every year the vine is pruned back to four arms or canes containing 8 to 12 buds that grew from the spurs left the previous year. Four new spurs are also selected and pruned back to 1 or 2 buds.
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Blueberry and Grape Weed Control
Destroy perennials before planting Mulch with organic materials or woven plastic mulch Keep alleys mowed short Hoe or pull weeds near plants Use shallow tillage Inset picture: Blueberry and grape planting with weed control obtained through mulching and hoeing. Discussion: Clean cultivation and hoeing or mulches may be used to control weeds in blueberries and grapes. Cultivation should be kept shallow to prevent injury to roots. Mulch is a good means of keeping weeds controlled. Plastic and mesh type mulches can be used in these crops. Plastic mulch will not last long unless it is covered with a thin layer of organic mulch material to protect it. Organic mulches such as a 4 to 6 inch layer of sawdust may be used to control weeds. This should be pulled away from the base of grape plants during the winter to protect from rodent damage to the vines. The microorganisms responsible for the decay of organic mulches will consume some of the nitrogen from the soil and can create a deficiency for the crop. If you use these mulches, be sure to allow for this when fertilizing. Non-running type plants such as fescue should be grown in the alleys between the rows of berries. With lawn grasses such as bermuda or St. Augustine, frequent maintenance will be required to keep grass from encroaching on the fruit planting. Alleys should be kept mowed.
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Diseases of Grapes Introductory slide
Discussion: There are several important diseases of Oklahoma grapes. Most of the diseases are caused by fungi, and if left uncontrolled often destroy the fruit before it can be harvested. In most situations, grape growers are going to have to commit to applying several fungicide sprays to get adequate control.
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Black Rot Guignardia bidwellii Grape
Foliar symptom Lesions with pycnidia (fungal fruiting structures) Pycnidia release spores (conidia) - infect newly-formed tissues throughout growing season Inset picture: Close-up of a Black rot lesion on a grape leaf. Note the pycnidia occurring in a ring near the outer edge of the lesion. Discussion: Black rot is the most destructive disease of grape and is common on grapes grown in Oklahoma. The first symptoms of the disease occurs on new growth. The leaves develop necrotic lesions that first appear as circular and red. As the disease progresses the spots enlarge, their margins turn black and the centers turn from red to brown. Often pycnidia can be observed within the dead tissue.
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Black Rot Guignardia bidwellii Grape
Foliar symptoms Appear in late spring Early - Small reddish spots Later - Spots turn brown with black margins Fruit symptoms: Appear after fruit half grown Small whitish areas on green fruit Inset picture: Grape leaves and fruit expressing symptoms typical of black rot infection. Discussion: Symptoms of black rot infections usually do not appear on the fruit until the fruit is about half grown. The spots first appear as small, whitish areas on green fruit. The white spots develop a brown ring that enlarges rapidly. The rotted fruit turns black and shrivels. This disease is the primary reason people lose grapes just before or just as the fruit ripens. Refer to OSU Fact Sheet #7643 “Black Rot of Grapes” for more information on black rot of grape.
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Powdery Mildew Uncinula necator Grape
Attacks all above-ground parts Early appears as whitish to grayish patches on leaves Mild temps and high RH favor development Control: Avoid excessive N Apply fungicides Inset pictures: Left - powdery mildew appearing as a whitish - gray growth on grape leaves; right - powdery mildew infection appearing as a grayish growth on a cluster of grapes. Discussion: Powdery mildew can attack all above-ground parts of the grape plant. It causes losses by adversely affecting the physiological function of the leaf, resulting in smaller fruit. It also directly infects the fruit resulting in lower quality and loss of yield. In early stages, whitish or grayish patches appear on leaves. If the infection is severe, the moldy growth develops on both the upper and lower leaf surface. On the fruit, powdery mildew first has the typical whitish to grayish appearance, but as the disease progresses, the fruit develops a brownish, russeted appearance. Infected fruits crack and drop from the cluster. Refer to Study Guide on grapes for more information on powdery mildew.
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Grape Disease Control Sanitation Spray schedule
Dormant season: February - March 10 (Black rot) First cover: new shoots = 2 leaves (Black rot) Second cover: Before bloom- shoot 12 to 18 inches (Black rot and Powdery mildew) Third cover: 10 days after petal fall (Black rot and Powdery mildew) Fourth cover: 2 weeks after third cover (Black rot and Powdery mildew) Inset picture: A grape in bloom. Discussion: In most situations, when grapes become infected with black rot and/or powdery mildew, they have to be sprayed with fungicides to obtain adequate control. However, if backyard grapes do not have a history of these diseases, application of fungicides may not be necessary. Black rot and powdery mildew can both cause crop failures for backyard fruit growers. It is important to begin spraying for these diseases early in the season. The inset picture shows a grape vine in bloom. Fungicide applications have to start before grapes reach this stage of growth. To be successful in controlling both black rot and powdery mildew, at least two fungicides applications should have been made before the grapes reach bloom stage.
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Grape Insect Pests Flea beetles Early season pest Two leaf stage
Prior to bloom Adults and larvae damage plants Destroy future canes 1 gen/yr Inset picture: Adult flea beetle Discussion: Early in the season flea beetles attack a wide range of plants including grapes. Watch for this pest and its damage. If swollen buds have holes or are eaten, look for tiny, dark, metallic beetles and spray if necessary. Flea beetles destroy the capacity of a bud to develop a primary or secondary shoot thus eliminating future canes. Damage by larvae and adults to the leaves occurs, but is negligible.
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Grape Insect Pests Grape berry moth Attacks leaves Attacks fruit
Tangled webs After petal fall 2 weeks later Later if present Clean up and burn leaf debris Petal fall and 7-10 days later Inset pictures: Top - Grape berry moth damage on fruit (note the webbing); bottom left - adult grape berry moth; bottom right - grape berry moth larva Discussion: One of the most serious pests of grapes is the grape berry moth. The larvae feed directly on the flowers and grape berries. Newly set berries are attractive to the moth. After eggs hatch they begin to feed and webs are often used to tie berries together. The first generation will pupate from cocoons within folded leaves. The second generation is made up of internal berry feeders only. “Stung berries” will be very conspicuous. The larva of the grape berry moth is green or purple and 3/8 inch long when fully grown. The adult moth is 5/16 -3/8 inch long: the inner halves of the front wings are bluish-gray, and the outer halves are tan or pale yellow with dark brown patches intermixed. Sanitation plays an important part in control of grape berry moth. Cleaning up and burning leaf debris will help combat this pest. Additionally, a petal fall spray followed by another application of a recommended insecticide 7-10 days later may be necessary.
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Grape Insect Pests Leafhoppers Adult and nymphs Treat upon emergence
Usually late season pest Multiple generations Inset picture: Leafhopper adult (lower right corner) and nymphs Discussion: Leafhoppers are yellowish-green to pale green in color in both the adult and nymphal stage. The winged adult is about 1/8 inch long (slightly larger than the wingless nymph). Adults will hop and fly while nymphs will run sideways when disturbed. Damage shows up as cupped yellow leaves. These insects have sucking mouthparts and may be involved in disease transmission. Some species of leafhoppers actually reduce photosynthetic capacity of the plant by their feeding causing reduced quality and yield. Some leafhoppers have a toxic saliva and cause ‘hopper burn’. Usually these pests are found during the late season and multiple generations can occur. If damage is evident and leafhopper numbers are high, a recommended insecticide may be applied. Eliminating weeds around the fruit planting will help minimize problems with leafhoppers.
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Grape Insect Pests Leafrollers
Treat when first brood emerges from rolled leaves Feed on buds, fruit, and leaves Pinch rolled leaves Remove mummies Inset picture: Leafroller larva with webbing used to roll leaf Discussion: Moths appear about late April and often lay eggs on grape clusters. The larvae can eat shallow holes in the berries that they web together. Multiple generations occur and the latter generations are the most damaging. However, serious infestations are not common. The red-banded is one of the more common leafrollers attacking grapes. The larva of the red-banded leafroller is 5/8 inch long when mature and is a pale green caterpillar. The adult moth is light brown with an irregular reddish-brown stripe across each front wing; it is about 1/2 inch long. Later infestations may be minimized by eliminating earlier generations, either through chemical control or hand removal of larvae and mummies.
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Grape Insect Pests Beetles Green June beetles Japanese beetles
Late season July and August 1 gen/yr Migrate Inset pictures: Top - Adult Japanese beetle; bottom - grape leaf damaged by beetle feeding activity Discussion: Beetles can be destructive to grapes. Japanese beetles have just recently become a problem in Oklahoma. However, they have been a serious pest in many other areas for an extended time. Adults emerge in June and July and cause a skeletonized appearance when they feed heavily upon the grape foliage. The adult Japanese beetle has a metallic green head, thorax and abdomen and are about 3/8 to 1/2 inch long. The wing covers are coppery brown with tufts of white hairs along the sides. Green June beetles are more likely to feed on ripe fruit. These beetles are much larger in size than the Japanese beetles. The adult is about 1 inch long and 1/2 inch wide with a flat surface on top. They are dull velvety green above with deep yellow to bronze margins, and metallic green below. These beetles migrate and often appear in large numbers overnight. An insecticide with a short days to harvest interval ( i.e.. carbamate ) is usually effective.
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Grape Harvest Fruit production - occurs second or third year of growth
Table grapes - sweet, plump, even in color Wine grapes - slightly tart, plump, slightly soft, even in color Discussion: Varieties vary in their color development at ripeness. Maturing grape berries enlarge, soften, and increase in sugar content. Harvest fruit during cooler part of the day by cutting the clusters from the vine with pruners or hand shears. Muscadine grapes are picked individually like other berries. Refrigerate the grapes soon after harvest. They will usually remain in good condition for three to 10 days. Refer to OSU Fact Sheet #6246 “Growing Grapes in the Home Garden” for more information on grape harvest.
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Bramble Fruits Blackberries and raspberries (F-6215 & 6239)
Perennial root Biennial canes Primocanes & floricanes Good longevity Annual pruning Easy to grow Variety selection most important Inset pictures: Top - blackberries; bottom - red raspberries Discussion: Bramble fruits include blackberries and raspberries. Details are given in the above mentioned fact sheets. The growth habit of brambles needs to be understood by growers in order to successfully grow them. The brambles have perennial roots but the stems die back nearly to the crown the second season of their life after maturing a single crop of berries. First year canes are called primocanes and second year canes which will bear fruit are called floricanes. Bramble fruits are among the easiest of fruits to grow. They will be productive for up to 15 years or more. They are more likely to produce fruit year after year than some other fruits. However, to successfully grow brambles, special attention should be paid to variety selection, pruning, and insect and disease control.
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Cane Growth Primocanes First year growth Floricanes Second year growth
Fruit bearing canes Inset picture: Line drawing illustrating primocanes on left and floricanes on right. Discussion: It is important to understand how brambles grow in order to prune properly and train if a trellis is being used. All brambles have biennial canes on perennial roots. The first year growth is called a primocane. The second year growth is the fruit bearing cane called the floricane. Pruning and training to a trellis requires the recognition of this trait of bramble fruits.
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Planting Bramble Fruits
Feb. or Mar. (dormant season) Spread roots and cover completely Only 1 cultivar needed 2 - 3 inches. above the roots 3 X 8 feet spacing Trailing cultivars need trellis Apply inches mulch after growth starts Apply fertilizer according to soil test Split application at bloom and after harvest Fertilize annually and retest in 3 years Inset picture: New planting of blackberry on a raised bed. Discussion: Plants or root cutting should be placed in rows during February or March. The plants or root cuttings should be kept moist until planted. When nursery plants are used spread the roots and plant slightly deeper than they stood in the nursery ( inches of soil over the roots ). If cuttings are used plant inches deep in the row. Plants should be spaced about 3 feet apart and 8 feet between rows. Stiff-caned varieties will need maintenance pruning while the trailing cultivars will need trellises. Trellis construction is detailed in F Whatever trellis method is selected, it will be beneficial if primocanes are trained to grow on one side while the floricanes are setting fruit on the opposing side. Organic matter is important to bramble fruit production. If soils are deficient in organic matter, add barnyard manure, chicken litter, or a green manure crop prior to planting. After planting apply inches of mulch such as pine bark or wheat straw. This will help conserve moisture, control weeds, and prevent winter damage. Annual applications of mulch should be made after the first killing frost in the fall. Split applications of fertilizer at bloom time and again after harvest is recommended. About 10 pounds of a complete fertilizer or 5 pounds of ammonium nitrate should be added depending on fertility of the soil. A soil test prior to planting and every 3 years thereafter should take the guesswork out of a fertility program.
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Pruning Brambles Removal of dead canes Thinning canes Lateral pruning
Heading back Inset picture: Line drawing illustrating cane thinning (top); lateral pruning (middle); and heading back (bottom). Discussion: Pruning of brambles involves annual removal of dead canes. This should be done as soon as possible to eliminate insect and disease problems associated with the floricanes for the previous season. The canes that have fruited gradually die, and removal after harvest or during the winter is a good management practice. Brambles should be thinned within the row to 3-4 per foot and the laterals should be cut back to about 12 inches in the early spring. Heading back is usually done in the summer to keep the brambles at a height that allows for movement within the planting to accommodate care during the growing season and harvest.
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Culture of Bramble Fruits
Black and purple raspberries and erect blackberries headed feet - June Red raspberry and thornless blackberry - not headed back - need support system Mid - March laterals should be pruned on all brambles to 12 inches All dead or diseased canes removed New canes are reduced to per plant Need 2 inches of water every 2 weeks (irrigate ) Discussion: Pruning and irrigation are two cultural practices necessary for good plant growth and well developed fruit. Because brambles can be such ramblers, pruning is critical to avoid ‘jungle growth’ which makes harvest difficult. It is a good practice to cut all canes to the ground as soon as harvest is complete. Additional pruning of new canes, based on variety and type of berry and whether a trellis is used, may be necessary. Laterals should also be pruned to about 12 inches in mid-March to simplify harvest and increase berry size. Trellis should be used for trailing and semi-erect varieties to prevent tangled growth and assist in harvest.
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Weed Control in Brambles
Destroy perennial vegetation before planting Mulch with organic matter Hoe or pull weeds near plants Keep alleys mowed short Inset pictures: Two pictures of brambles growing under good weed control conditions. Discussion: In blackberries and raspberries, clean cultivation or organic mulches may be used to control weeds. Cultivation should be kept shallow to prevent injury to roots. Mulch is a good means of keeping weeds controlled. Plastic and mesh-type mulches are not a good choice because these will interfere with the growth of new shoots. Organic mulches such as a 4 to 6 inch layer of sawdust may be used to control weeds. The microorganisms responsible for the decay of organic mulches will consume some of the nitrogen from the soil and can create a deficiency for the crop. If you use these mulches, be sure to allow for this when fertilizing. Non-running type plants such as fescue should be grown in the alleys between berries. With lawn grasses such as bermuda or St. Augustine, frequent maintenance will be required to keep grass from encroaching on the fruit planting. Alleys should be kept mowed.
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Blackberries Hardy plants - few pests Most productive bramble
Grow well on wide range of soils Well-drained sandy soil preferred Enriched with humus Prune to prevent rambling Two forms erect and trailing Inset pictures: Top - blackberries in bloom; bottom - blackberry fruit Discussion: Blackberries are typically larger and more vigorous than the other brambles. Blackberries are very productive and a few plants will provide adequate yields for most families. Plants do well on a wide range of soils but preference is given to light, well drained soils with high moisture retention. Therefore, it is important to use compost and mulches for vigorous plant growth. This will increase organic matter content and conserve moisture. Blackberries are available in two forms (erect and trailing) and have a number of different names. The ordinary blackberry is stiff-caned and will stand by itself while the trailing forms are tender and need trellising. The southern trailing forms are often referred to as dewberries. Thorned and thornless varieties are also available.
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Blackberry Varieties Erect blackberries recommended
Varieties listed in order of ripening Choctaw (thorned) Cheyenne (thorned) Cherokee (thorned) Arapaho (thornless) Shawnee (thorned) Navaho (thornless) Inset picture: A segment of cane from a thorned blackberry and a segment of cane from a thornless variety. Discussion: Variety selection is important and should be considered before planting. The harvest season can be extended by careful selection. The above varieties would allow for ripening fruit from the first week of June through the middle of July.
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Raspberries New varieties better suited for south
Pulls free from core when picked Red, yellow, purple, and black varieties Red and yellow - more cold tolerant Discussion: Raspberries have not been recommended for our growing area in the past. However, some new varieties have created a renewed interest in raspberries. Since raspberries often break bud during warm periods in January or February, the plants are susceptible to cold damage later in the season. Raspberries are not heat tolerant and should be placed in 50% shaded site. The distinguishing factor of raspberries is the fact that it pulls free of its core when picked. Other bramble fruits take the core with them when picked. They are an excellent berry for fresh use and few berries can match their flavor. If gardeners are willing to accept some failures with raspberries, they afford a delicious berry when they produce a harvestable crop. Many varieties exist and a variety of colors are available: red, yellow, purple, and black. Red and yellow varieties are trailing plants and are more cold tolerant, while the purple and black raspberries are stiff-caned. Red and black varieties appear better suited for growing in the south.
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Diseases of Brambles Introductory slide
Discussion: Blackberries and raspberries grown in backyard situations are often produced successfully without diseases causing significant problems. Occasionally the canes and fruit will be attacked by diseases and in those situations the appropiate control measures need to be implemented.
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Anthracnose Elsinoe veneta Blackberry
Reduces size and quality of fruit on infected canes Symptoms on canes: Early - light grayish spots about 1/8 inch in diameter Late - spots enlarge and develop purple borders and ash-gray centers Inset picture: Segment of blackberry cane expressing typical symptoms of an anthracnose infection. Discussion: Anthracnose is a common cane and foliage disease of blackberry and dewberry sometimes called dieback. The disease first appears in the spring as small purplish spots on new shoots and purple-bordered spots on leaves. Spots on canes enlarge, usually develop an oval shape, and gradually turn gray. Ends of badly infected canes die back. Erect types are less susceptible than the more spreading types. Late dormant fungicide application will help prevent infection.
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Rosette Cercosporella rubi Blackberry
Symptoms: Clusters of foliage at terminals or along fruiting cane Flower buds large and red Petals purplish and sepals elongated Infected flowers do not set fruit Control = Sanitation Remove infected canes Plant resistant varieties Inset picture: Segment of blackberry cane with cluster of foliage at the terminals, typical of rosette infection. Discussion: There are several situations in which blackberries develop a proliferation of vegetative growth. Often this type of symptom is blamed on virus infections. Although virus infections do occur in blackberries, the fungal disease rosette is a probable cause. The symptoms of rosette appear in the spring as bunches or clusters of foliage at terminals or along fruiting canes. The flower buds, sepals and petals all can be affected by this disease (see slide). Rosette reduces yield because infected flowers do not set fruit. Fungicides are not reported to control this disease. Good sanitation practices have to be followed to prevent the spread. Remove infected canes as soon as they become noticeable. Destroy all wild berry plants in the vicinity, remove and burn all fruiting canes soon after harvest and keep plants adequately spaced for good air circulation. Where heavy infection has occurred, mowing all canes to ground level may be necessary. Thornless varieties Navaho and Arapaho are reported to be resistant.
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Fruit Rot Botrytis cinerea Blackberry
Infects blossoms and fruit Symptoms on fruit appear near maturity Watery rot develops on few drupelets Infected drupelets turn tan Moist weather allows for development of visual fungal growth Inset picture: Blackberry fruit expressing typical tan coloration associated with infections of Botrytis fruit rot. Discussion: Mild, wet weather conditions are ideal for fruit rot. Overripe fruit is most susceptible. Timely harvest and spacing plants to encourage good air circulation helps prevent fruit rots. Fungicides will provide control of fruit rots.
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Control of Blackberry Diseases
Sanitation Proper plant spacing Apply recommended fungicides Spray schedule: Dormant season Pre-bloom % bloom Full bloom Petal fall Discussion: There are several diseases, in addition to the ones included in this program (i.e. orange rust, cane and leaf rusts, and Septoria leaf spot), that may attack blackberry and result in reduced yields and/or poor quality fruit. The most effective control measures for blackberry and raspberry are those taken before the diseases become serious. Recommended varieties that are resistant to the major diseases should be planted. Cultural practices that promote vigorous growth are also important in growing healthy blackberries and raspberries. Control can often be obtained through good sanitation practices and spacing plants properly to allow good air circulation. However, blackberry plantings with a history of diseases such as anthracnose, or berry rot are going to require fungicide applications to obtain control. The result will be higher quality fruit and higher yields.
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Insects of Bramble Fruit
Raspberry crown borer Adult is moth, grub in cane Damages crown area Reduced vigor & breakage Galls below soil line Eggs laid in late summer Larvae bore into canes 2-yr. life cycle Dig and burn infested canes pre-bloom Inset pictures: Top left - Adult raspberry crown borer; top right - borer damage near crown of raspberry cane; lower left - close-up of grub in cane; lower right - grub in cane Discussion: The eggs of the raspberry crown borer are laid by a moth. When hatching occurs, the larvae tunnel into the canes and overwinter. Larvae stay in the canes for 2 years and during the first year, they cause swellings or galls below the soil line. During the second year feeding continues until the larvae are mature in about June or July. At this time they pupate and the moths emerge from July to September and start the cycle over again. Dig out and burn infested galled canes and crown in late fall or early spring. Insecticide sprays applied pre-bloom may also be effective. Because of the 2-year life cycle, if an infestation is discovered, repeat controls for at least 2 years.
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Insects of Bramble Fruits
Cane borers 2 spp. Raspberry cane borer Red-necked cane borer Adult stage is beetle Tip girdling and wilting Enlargement or galls Prune and burn infested canes Inset pictures: Top - damage (wilting) caused by the raspberry cane borer; bottom - damage caused by the red-necked cane borer. Discussion: Two species of cane borers can affect bramble fruit production. The raspberry cane borer and the red-necked cane borer. Both species are beetles in the adult stage. They are black with copper or yellow markings just behind the head and are about 1/2 inch long. The raspberry cane borers cause the tips of canes to wilt as a result of girdling activity during their first year. They feed down to the crown during the following spring and spend the second winter in the crown. Pruning out infested canes an inch or so below the girdled area will help control this pest. The red-necked cane borer is found up in the canes near swollen or gall-like areas. Only one generation occurs each year. Cutting out and burning infested canes during winter is the best approach to control. Pre-bloom sprays, followed by a second application 2 weeks later, may also help reduce the incidence of borer damage.
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Insects of Bramble Fruits
Leafhoppers Adults and nymphs damage plant Blotchy yellow leaves Reduced cane growth Premature leaf drop Overwinter beneath leaves & trash Inset picture: Leafhopper nymphs Discussion: Adult leafhoppers are about 1/4 inch long and suck sap from affected plants. The adult overwinters under leaves and trash near the planting. Eggs are laid on the lower surface of leaves and nymphs hatch and feed causing damage. Blotchy yellow leaves and reduced cane growth are obvious symptoms. Premature leaf drop is also attributed to this pest. Because of the feeding habits and mouthparts of this pest, it can transmit viral diseases.
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Insects of Bramble Fruits
Aphids Feed on underside of leaves Remove sap High reproductive rate Be selective when spraying insecticides to avoid aphid problems Inset picture: Aphids - adult and young. White objects are exoskeletons shed by growing aphids. Discussion: Aphids are very numerous and attack a wide variety of plants. These tiny insects (less than 1/8 inch) are variable in color. They may be yellow, green, purplish, or black in color. Their feeding activity removes sap from the plant and their high reproductive rate can result in curled, twisted, discolored, stunted leaves. In addition, ‘honeydew’ secreted by the insects leads to sooty mold causing the leaves to appear black and dirty. Fruit may be small, misshapen, and covered with honeydew or mold if heavy infestations are allowed to develop. Blackberry psyllids can be damaging to bramble fruits. They are somewhat similar to aphids, but have strong jumping legs. Oftentimes they are mistaken for wool aphids due to the waxy secretions they produce. Under high magnification they resemble cicadas, Insecticide selection in the growing season can contribute to aphid problems. Avoid insecticides that kill beneficials. Insecticidal soaps have proven effective against this soft-bodied pest.
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Insects of Bramble Fruits
Leafrollers Not serious pest Foliage feeder Pinch or remove Treat for large #s Inset pictures: Top - adult leafroller moth; bottom - leaf roller larvae Discussion: Leafrollers are caterpillars that are the immature stage of several moth species. They roll leaves up and feed inside. Some species use large amounts of silken threads to tie leaves together. Although plants may become heavily infested, they usually do not affect berry production. Leaf picking and removal can help control this pest. Under heavy infestations a foliar insecticide spray may be needed.
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Harvesting Brambles Blackberries Harvestable second year
Allow to fully ripen Soft, dark blue-black Pick while cool & refrigerate Raspberries Pick 2x weekly Minimize handling Discard overripe or decaying Keep cool All brambles should bear for many years Discussion: When harvesting bramble fruits, “taste-testing” is one method of assuring high quality berries. All the brambles should bear fruit the second year. However, the first year or two of production will not be as productive as older plantings. All brambles should be allowed to fully ripen. The core should be almost undetectable in blackberries and raspberries should separate from the core very easily when picked. To minimize spoilage, one should discard any berries that are overripe, injured or decaying. Berries keep several days under cool conditions. However, quality decreases rapidly with time so berries should be eaten fresh or processed as soon as possible.
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Delicious and Nutritious!
Strawberry Inset picture: Strawberry fruit Discussion: Strawberries are a delicious and nutritious fruit. They can be grown throughout Oklahoma. Home plantings may be used for the family and for supplemental income. Introductory slide Inset picture: Strawberry fruit Discussion: The strawberry is rated by many backyard fruit producers as their favorite fruit. It is the first to ripen in the spring, does not require much space, and is easy to grow. Strawberry is a member of the Rose family and is native to temperate regions. Wild strawberries are native to America. The common strawberry is believed native to Chile and western North America; it has probably hybridized to some extent with the wild strawberry of eastern North America. Delicious and Nutritious!
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Planting Sites and Methods
Use in a bed, the vegetable garden or as landscape Grow in a matted row as a perennial crop or on plastic mulch as an annual crop Inset picture: Left: Grower inspecting commercial strawberries; top right - strawberries growing in landscape planting; lower right - commercial strawberry planting growing on black plastic mulch. Discussion: Strawberries may be used in a vegetable planting, in a dedicated bed or as part of the landscape. *Note - avoid planting among tree fruit as pesticide sprays may drift onto ripening strawberries. They may be grown as an annual using a plastic mulch system. This is better adapted to commercial producers. If you are interested in this system, your County Extension Educator can provide additional information. The matted row is a common system used in many backyard gardens. Once it is established, the matted row system will last for several years if it is maintained properly.
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Strawberry Site Selection
Avoid low areas Provide irrigation Full sun Avoid perennial weeds Avoid areas where other berries or Solanaceous crops have been grown Discussion: One key to successful production is proper site selection. Avoid low-lying areas that may be susceptible to poor drainage or where cool air may settle and cause frost damage. Plants will grow best in full sun. Irrigation will be needed at times, so choose a site where it will be available. Choose a site where there are no perennial weeds, which would be difficult to control once the berries are established. If weeds are present, control them before planting. To reduce chances of disease problems, avoid areas where berries or Solanaceous crops (tomato, potato, eggplant, etc.) were planted previously. Some examples of diseases that strawberries and tomatoes have in common are: Bacterial wilt (Pseudomonas solanacearum), Verticillium wilt (Verticillium albo-atrum & V. dahliae), Anthracnose fruit rot (Colletotrichum dematium), as well as Root-knot nematode (Meloidogyne spp.)
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Strawberry Soil Requirements
Soil Acidity and Fertility pH 6.0 to 6.5 ideal Add lime for soil pH adjustment 1 year in advance Add P and K during bed preparation Discussion: Test soil to determine soil acidity and nutrient status. If soil is acid, apply lime to adjust. Your County Extension Educator can help with interpretations of soil test results. If P and K are needed, these should be mixed into the soil before planting.
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Strawberry N Requirement
Apply N - Aug. to Sept. for fruit bud set 3 lbs ammonium nitrate/200 ft row Soil test established plantings Excess and inadequate fertilization are wasteful Inset picture: Single strawberry plant in bloom Discussion: Timing of N applications is critical to successful fruit production. Applying N in the spring results in vegetative growth and will not increase fruit production, late summer is the time to apply N. Established beds need to be tested for soil fertility. If yearly applications of fertilizer have been applied, there is a good chance the P and K levels will be adequate if not too high. Soil testing will also identify beds that need additional fertility in order to reach full production potential. Apply P and K based on soil test recommendations.
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Strawberry Variety Selection
Bearing types June-bearing - Produce a single spring crop. Berries ripen from early May to late June, depending on variety. Everbearing - Fruiting begins mid-May through fall. Fruiting begins mid-May to mid-June. Fruit quality and total yield may be less than for June-bearing types. Discussion: Choose varieties so that you will have fruit when you need it. You may want to plant several varieties in order to prolong your harvest period. June-bearing varieties vary in ripening date from early May to mid June. June-bearing are the most successful type for Oklahoma. Everbearers set fruit in the spring, to a limited extent in the summer, and again in the fall. Overall yield, fruit size, and quality may not be as good as with the June-bearing types.
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Strawberry Variety Selection
Select locally adapted varieties Certain varieties require another variety for cross pollination Varieties differ in sweetness, preservation quality, pest resistance and fruiting period. Plant multiple varieties to prevent crop loss to disease and frost events See OSU Fact Sheet-6214 Discussion: Variety selection is a personal choice based on preference in fruit size, flavor, harvest dates, etc. However there are some basic factors everyone should consider in selecting strawberries for the backyard garden. One of the important points to consider is pest resistance. Selection of varieties that have resistance to the common disease and insect pests can save a gardener time and expense by decreasing the need for applying pesticides on a regular spray schedule.
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Plant Selection Tips Select varieties
Find a reliable and experienced nursery Place your order early Accept only healthy-looking plants that are certified as virus free Inset picture: Strawberry being grown in a hanging basket. Discussion: It is advisable to buy strawberry plants from an established and experienced nursery. When plants arrive, or are purchased, inspect the root and crown areas carefully for obvious symptoms of disease and insect pests.
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Plant Establishment Propagate with rooted runners from mother plant
Inset picture: Strawberry plants producing runners and small daughter plants. Discussion: Propagate by removing runners from mother plants and planting into new beds. This is usually done between February 1st and March 20. In southeast Oklahoma, plants may be set in October or early November. Be sure to irrigate and protect these plants from windy and extremely cold conditions.
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Planting Techniques Remove all but 2-3 leaves Roots may be clipped
Keep plants moist during and after planting Space plants 1.5 to 2.5 feet Plant with crown at soil surface Inset pictures: Top - line drawing illustrating proper planting depth and proper number of leaves; bottom - planting strawberry, note how the root system has been spread to cover bottom of planting hole. Discussion: Prepare runners for planting by removing excess leaves. If roots are too long for easy setting, they may be trimmed with scissors or sharp knife. Spacing between plants may vary depending on the vigor of the variety being grown. Check with your plant supplier for recommendations for your variety. It is critical to set the plants so that the crowns (the area where the leaves arise) are at the soil surface once the soil is firmed around the plant. If too deep, plants may rot. If too shallow, plants may dry out. Be careful to keep plants from drying out during and after the planting process. Until new roots are developed, plants are especially susceptible to desiccation.
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Strawberry Site Preparation
Kill existing vegetation Apply soil amendments such as fertilizers and organic materials Construct beds Provide for drainage Inset pictures: Top - grower preparing to add fertilizer to planting site; bottom - grower working with compost that can be added to planting site to improve soil organic matter and fertility. Discussion: Site selection is important to successful strawberry production. Time and frustration will be saved if the site is cleared of weeds, especially grasses such as bermudagrass, months prior to planting. The soil should be tested, the required nutrients added, and the pH adjusted as recommended. Select an area that is well drained or improve the drainage if the area tends to be “wet”. Planting strawberries in soils that have drainage problems leads to problems with root rots, other diseases, and insects.
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Irrigation for Strawberries
Soil moisture is important for new and established plantings Strawberries are shallow rooted Water every two weeks in spring and summer, as needed Drip or trickle type irrigation is preferred Inset picture: New strawberry planting growing under a drip irrigation system Discussion: The importance of water at planting has already been discussed. Because strawberries are shallow rooted, soil moisture is critical for optimum plant growth. With new plantings, if there is no rainfall during any two week period in the spring or summer strawberries should be irrigated so that the soil is wetted to a foot deep. Drip or trickle type irrigation is preferred since less water is wasted and disease problems may be lessened. When renovating established plantings, irrigate after the renovation process is complete.
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Bed Renovation Begin after harvest completed
Keep beds narrow and orderly Helps to maintain plant health and productivity Inset pictures: Left - Established strawberry planting in need of renovation (too many plants); right - renovated strawberry planting ( plants have been thinned to allow for growth of runners and daughter plants). Discussion: Bed renovation is the process of narrowing rows and and controlling weeds after harvest is completed. This will help keep the planting orderly and keep plants healthy and productive. To renovate, narrow the rows to 8 to 10 inches with a hoe. If your soil test indicates that fertilizer is needed, apply it now. Irrigate after renovation is completed.
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Benefits of Mulching Winter mulch - Protects from repeated freezing and thawing and desiccation. Spring/summer mulch - Keeps fruit clean, prevents erosion, helps control weeds Inset pictures: Top right: strawberry with frost on foliage; lower left - strawberry mulched with straw. Discussion: Winter mulching will help protect plants from repeated freezing and thawing and also from desiccation. For the summer, leave some mulch in the row. This will keep fruit from contacting the soil and protect fruit quality. Mulch also helps prevent soil erosion and weeds. Fabric mulches are supported by hoops. An additional benefit is protection from hail damage.
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How to Mulch Apply mid- to late-December
Cover row with 3 inches of clean straw Uncover foliage when plant growth resumes in the spring Fabric mulches may be used - see OSU Fact Sheet F-6214 Discussion: Clean straw (free of weeds) or similar materials may be used. Apply mulch in mid- to late- December, after the plants have become cold hardy. Plants should be covered loosely, to a depth of three to four inches. Remove mulch from the foliage when strawberries resume growth. New growth will be light green in color. This is usually in March. Move mulch to the side of the row. If a late frost is expected, plants can be covered again.
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Weed Control in Strawberry
Kill sod and perennial weeds a year before planting Excess fertilization favors weeds Keep planted beds free of weeds Mulch helps prevent weeds See OSU Fact Sheet-6243 Inset pictures: Top left - weed-free strawberry planting. Weed control obtained through hand cultivation and herbicides; top right - weed-free strawberry obtained through hand cultivation and mulch; bottom - weedy strawberry planting Discussion: Start with a site that is free of weeds when planting strawberries. If perennial plants such as bermudagrass, clover or nutsedge are present, destroy them before planting. Check with your County Extension Office for information on how to accomplish this. Over-fertilizing may benefit weeds more than strawberries. If weeds become established and are allowed to grow they may become more difficult to control in the future. Use bed renovation to keep berry plants vigorous and to keep weeds in check. Keeping mulch between rows will help suppress weeds during the growing season. Plastic mulch culture, in which strawberries are grown as an annual crop, may help reduce the weed control burden of growing strawberries. Refer to OSU Fact Sheet #F-6214 “Growing Strawberries in the Home Garden” for proper fertilization procedures for strawberry.
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Diseases of Strawberry
Introductory slide Discussion: In Oklahoma strawberries are not a highly diseased fruit crop. Following proper cultural practices and planting varieties recommended for Oklahoma will result in stronger plant growth, and the plants will be less likely to be attacked by diseases. However, in certain situations, and often in older plantings, diseases become established and decrease the amount of harvestable fruit.
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Common Leaf Spot Mycosphaerella fragariae Strawberry
Fungal disease Lesions on leaves, calyxes, petioles, stolons Leaf lesion - circular, small, deep purple, centers white to gray Inset picture: Strawberry leaf showing symptoms of common leaf spot Discussion: Symptoms of common leaf spot first appear as lesions on the upper surface of leaflets and on petioles, fruit stems and fruit as small, deep purple, indefinite spots. As the spots become older they enlarge and become circular. The central part of the spots turns brown, later turning white, with dark purple borders surrounding the spots. Symptoms on the lower surface of a leaflet will be similar but the coloring is not as intense. When spots are numerous, a portion of the leaflet, or even the entire leaflet, may be killed.
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Leaf Scorch Diplocarpon earlina Strawberry
Symptoms: Irregular shaped purplish spots Brownish centers Leaves dry up and edges curl up Petioles become infected = death of fruit Inset picture: Strawberry leaves expressing symptoms typical of strawberry leaf scorch Discussion: Lesions produced by leaf scorch are larger than those produced by common leaf spot. Leaf scorch is characterized by numerous irregular, purplish blotches 1/16 to 1/4 inch in diameter. The centers of the blotches become brownish (not white or gray as with common leaf spot). Blotches can coalesce, and the entire leaf blade becomes purplish or reddish. Dark, glistening structures that look like small grains of pepper (acervuli) appear scattered over the upper surfaces of the lesions. Later, the affected leaves dry up, their margins curl up, and they assume a scorched appearance. The most serious injury occurs from spotting on fruit-stalks and caps. The spotting on these structures reduces the size of the fruit, or kills the entire cluster. Berries that are infected before they ripen never fully ripen and are inedible. Leaf spots occurring on runners can weaken developing plantlets resulting in poor production the following spring. Leaf spots are most prevalent in the spring and fall during cool, damp weather, but occur throughout the summer as long as moist conditions occur.
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Fruit Rot Botrytis cinerea Strawberry
Young blossoms susceptible Fruit infections - soft, light brown, enlarge rapidly Berry rot control obtained with fungicides applied after petal fall Control Cultural practices Fungicides Inset pictures: Upper and lower photo of strawberry fruit infected with Botrytis fruit rot. Discussion: Many fungi are capable of causing a fruit rot of mature or near-mature fruits of strawberry. One of the most serious berry rots is caused by the fungus Botrytis cinerea and is known by common names such as gray mold, and Botrytis fruit rot. This disease greatly reduces the amount of edible fruit. Problems with this disease are usually associated with the fruit rot that begins as a light tan spot developing on infected berries. As the disease progresses, the berries become soft, mushy, and begin to rot. A fluffy gray to brownish mold may cover rotting berries. Flowers are also attacked by this fungus. Early infection can kill the blossom or become latent and survive within the bloom and developing fruit without producing symptoms. The latent infections express themselves when the berries begin to ripen. Berries can also be directly infected when a healthy berry touches a decaying one, by touching infected soil, or a dead leaf on which Botrytis is surviving. It is too late to begin a fungicide spray program when the ripening fruit begins to express symptoms of gray mold. The fungicide applications should be initiated when the plants are in bloom to prevent the latent infections of the berries. The spray schedule followed to prevent leaf spots will also help in controlling gray mold but will have to be extended further into the season.
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Strawberry Disease Control
Spray schedule: First application - 10% bloom (Leaf spot, Leaf scorch, Powdery mildew) Second application - full bloom (Leaf spot, Leaf scorch, Powdery mildew) Third application - petal fall (Berry rots, and leaf diseases) Subsequent applications may be necessary (Berry rots, and leaf diseases) Avoid overhead irrigation; fungicides applied on 7- to 10- day schedule; refer to fungicide label for waiting periods Discussion: The infection levels of foliar disease can sometimes be reduced by employing non-chemical or organic methods coupled with good cultural practices. However, in some situations, fungicides are required to prevent diseases from causing unacceptable levels of yield reduction. When fungicides are used they need to be sprayed on a regular schedule. Spraying infrequently and on an irregular schedule is of no benefit. The first fungicide application should be applied at 10% bloom followed by at least two more applications on a 7-day schedule. Additional applications may be required if disease pressure continues to be high.
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Red Stele Phytophthora fragariae Strawberry
Lateral roots destroyed = Rattail appearance Appears similar to effects of water logging Inset picture: Strawberry crown with roots expressing “rattail” symptom Discussion: Strawberry is host to several root rotting and wilt diseases. Strawberry plants infected with a root rot or wilt will grow poorly, frequently be stunted, have reduced berry production, and will frequently wilt. One of the more common root diseases is called red stele. Red stele is easily recognized by a characteristic symptom that it produces in infected strawberry plants. Thin, spindly roots, descried as having a “rattail” appearance, is a strong indication that the plant is infected with red stele.
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Red Stele Phytophthora fragariae Strawberry
Symptoms: stunted plants; discolored leaves (orange, red, yellow) Red discoloration of stele Control: Improved drainage Resistant varieties Inset picture: Strawberry root infected with red stele expressing the red discoloration of the root stele. Discussion: In the spring, the center of an infected root (stele) will be discolored reddish brown instead of the normal pale yellow color. Black tips or patches may occur on the feeder roots and the infected plants eventually die. Phytophthora fragariae is a fungus associated with wet, cool soils. Avoiding planting sites that have high clay content soils and selecting well-drained sites will help prevent this disease. In addition, there are strawberry varieties that are tolerant or resistant to red stele. There is no chemical control available for red stele.
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Verticillium Wilt Verticillium albo-atrum Strawberry
1st year plants most susceptible Browning of outer leaves; stunted inner leaves remain green = most distinguishing symptom Control - Resistant varieties Inset picture: Strawberry plant with brown outer leaves and stunted inner leaves Discussion: Verticillium wilt of strawberry occurs in Oklahoma. The pathogen is a soil-borne fungus (Verticillium albo-atrum) and it has a wide host range. Strawberry plants infected with Verticillium wilt are affected most severely in their first year of growth. Their outer leaves show marginal and interveinal browning and eventually collapse. Inner leaves are stunted but tend to remain green and turgid until the plants die. This is a distinguishing symptom of Verticillium wilt. Control of Verticillium wilt is obtained through the use of resistant varieties.
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Control of Root Rots and Wilts
Resistant varieties Early Glow and Sunrise RS and V SureCrop Mohawk (new) RS (5 races) Discussion: Planting disease-resistant strawberry varieties is a practical and inexpensive way to control several of the common strawberry diseases. Varieties are available that have resistance to red stele, Verticillium wilt, anthracnose, powdery mildew, several of the leaf and stem diseases and fruit rots. However, when selecting varieties, remember to select those that are adapted to Oklahoma growing conditions. Varieties that are not adapted to Oklahoma may become stressed and fall victim to disease.
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Strawberry Insect Pests
Strawberry weevil Adults emerge in early spring Damage blossom buds Lay eggs, girdle buds One generation/yr Timing critical ‘‘Clippers’’ Inset pictures: Top (left to right): Strawberry weevil larva, pupa and adult; Bottom: Strawberry plant expressing symptoms of strawberry weevil damage (clipped petioles). Discussion: This pest is a dark reddish-brown weevil about 1/10 inch long with a head prolonged into a slender, curved snout about 1/2 as long as the body. Early fruit buds are punctured and the immature pollen is fed upon by the strawberry weevil. Females deposit a single egg in the buds and girdle the buds. Then the stem is clipped so that it hangs or dangles by a thread of plant material. Only one generation occurs each year and these are most likely to occur when adjacent woodlots are nearby. They are commonly called ‘clippers’. They also occasionally attack other small fruits.
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Strawberry Insect Pests
Aphids Post bloom Sap feeders Stunting and leaf curling Honeydew and sooty mold Spray before tightly curled Inset picture: Strawberry stem infested with aphids Discussion: Colonies of aphids may develop on strawberries as well as other plants around the home. There are numerous natural enemies of aphids including lady beetles, lacewings, parasitic wasps, etc. Natural control will frequently be the best option. However, when large populations occur and this sap feeding insect starts stunting plants, curling leaves and honeydew begin to accumulate, it may become necessary to spray with a recommended insecticide. Watch for this small insect on the lower sides of leaves. Many species of aphids occur and most are in the 1/10 inch range with variable colors. If leaf cupping begins and large numbers are present, spray before the leaves are tightly curled. Concentrate on the lower sides of the leaves. Insecticidal soap has been successfully used to control these soft-bodied insects. Unwarranted use of insecticides early in the season contributes to aphid problems, so spray only when needed.
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Strawberry Insect Pests
Leafrollers Post bloom Feeds on leaves and/or fruit Skeletonizes leaves from underside Folds and webs leaves together Multiple generations Foliar sprays Inset pictures: Leafroller larva with webbing. Discussion: In its early stages, leafrollers may feed on either side of a leaf. As it becomes larger, it feeds on the upper side of the leaf. Here, it attaches a fine silk thread to leaves and folds the leaflet at the midrib forming an enclosure. Continuous feeding can cause the leaf to die and several leaves may be webbed together. Multiple generations occur. The adult is a reddish-brown moth about 1/2 inch in size. Young larvae are usually pale green but change to gray-brown as they mature. Mature larvae reach about 1/2 inch in length. Populations are usually kept in check by beneficial insects. A few rolled leaves may be hand-picked. However, if populations become large, a foliar application may be necessary.
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Strawberry Insect Pests
Spittlebugs Postbloom Overwinter as egg attached to plant Eggs hatch and nymph feeds 5-8 weeks Reduced yield, stunted berries Weakened plants Inset pictures: Top - close-up of spittlebug and spittle-like substance; bottom - strawberry plant with spittle-like substance on stems. Discussion: Spittlebugs have sharp beaks and pierce the stem of plants. They are readily recognized by the spittle-like substance with which they cover themselves in the nymphal stage. Inside the white, frothy, irregular masses, small green nymphs can be found less than 1/4 inch in size. One generation occurs each year. Nymphs stay inside the spittle mass for 5-8 weeks before the adult emerges. Feeding activity causes the plants to become stunted and berries do not attain full size. Foliar sprays after bloom will provide control if this pest becomes a problem.
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Strawberry Insect Pests
Sowbugs Post bloom Nocturnal Feed on fine roots Attack fruit and leaves touching ground Problem under high populations only Inset pictures: Top - wide angle view of many sowbugs; bottom - close-up of individual sowbug Discussion: Sowbugs are not true insects, but are closely related arthropods. They are actually crustaceans. They are dark gray, with hard, flattened, segmented bodies, about 1/2 inch long , with many legs. They often are associated with high organic matter. If high populations are present they may cause damage by feeding on fine roots and later they may attack fruit and leaves that are near or touching the ground. During the day, pillbugs or sowbugs hide in dark, damp places. They feed and move about during the night. Eliminate moist, dark breeding sites. Baits or insecticide sprays may be used if infestations warrant control.
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Strawberry Insect Pests
Lygus bugs Adult 3 - 5 gen/yr Damage Puncture young fruit “Button berries” Post bloom Inset pictures: Top - close-up of lygus bug; bottom - strawberry fruit with lygus bug damage = “button berries” Discussion: Adults are small, flat, football-shaped insects that are greenish or brown in color. They range in size from 1/4 inch to 1/2 inch in length. The nymphal stage resembles aphids when young. Multiple generations can damage the crop by puncturing the fruit and causing ‘button berries’. A post bloom spray is often needed for controlling this pest. Clean cultivation will help reduce the incidence of this pest. Multiple generations are found from May until heavy frost.
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Strawberry Insect Pests
Mites Post bloom Reddish - brown blotches Silken threads Stunted fruit Treat at first sign Repeat sprays until clean Inset pictures: Top - close-up of mites; middle - mites on bottom of leaf; bottom - strawberry plant expressing symptoms of mite damage Discussion: Mites are scarcely visible to the naked eye. They attack a wide variety of plants. Hot, dry weather favors mite problems. Since it is found on many ornamentals it is likely to be found on strawberry plantings as well. The adult is about 1/50 of an inch. Silken webs are found under heavy infestations. Plants lose their healthy green color and appear mottled and have a coppery-bronze color. Mites suck sap and also interfere with normal physiological processes such as the production of sugars. Treat at first sign of infestation with a miticide such as Kelthane and repeat until clean.
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Blueberry Inset picture: Blueberry fruit and foliage
Discussion: Blueberries can be an excellent choice for a home fruit crop. However they require more attention to soil preparation, maintaining proper soil pH and irrigation than many of the other fruit crops. The fruit can be used in cooking or eaten fresh. They can also be frozen, canned, preserved as jams or dried for use as a substitute for raisins.
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Site selection Blueberry
Avoid areas prone to late frosts Well drained Full sun pH 4.0 to 5.5 Sandy loam with added organic matter - ideal Control weeds, especially bermudagrass and wild blackberries Inset picture: Blueberry bush with trickle irrigation Discussion: Blueberries need a site in full sun. Excellent drainage is essential, hence, raised beds are highly recommended. Areas prone to frost should be avoided. Deep, well-drained sandy loam soils with added organic matter are ideal. A pH of 4.0 to 5.5 is necessary for optimum plant nutrition, growth and production. Site should be acidified several months prior to planting. Clear site of weeds, especially bermudagrass and wild blackberries.
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pH Requirement Blueberry
Soil test to determine pH Add sulfur to lower pH Inset picture: Bag of sulfur Discussion: Blueberries require an acid soil (4.0 to 5.5) and many sites in Oklahoma will require some adjustment to the soil to be within the ideal pH range for blueberry production. In order to accurately determine the soil pH, a soil test must be submitted to OSU Soil Lab for analysis. Sulfur may be added to lower the soil pH. The amount of sulfur required will be determined by the soil pH and the soil type.
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Sulfur/pH Table lbs. of S per 100 square feet to lower soil pH one unit
Sand: 1.0 to 1.5 Loam: 2.0 to 3.0 Clay: to 4.0
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Blueberry Types Highbush Rabbiteye Southern Highbush
Inset picture: Blueberry blossoms Discussion: There are three basic types of blueberries that will grow in Oklahoma: highbush, rabbiteye, and southern highbush. Refer to Blueberry Production section of Study Guide and to OSU Fact Sheet #F-6248 “Blueberry Production for Home Garden”.
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Highbush Blueberry 5 to 25 feet tall Ripen in May
Requires 800 hours of chilling Performs best in northern Oklahoma Inset picture: Example of highbush blueberry growing in NE Oklahoma Discussion: Highbush blueberries may grow 5 to 25 feet tall (8 to 10 is average) and require 800 hour of chilling below 45 degrees F. They perform best in northern Oklahoma.
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Rabbiteye Blueberry 5 to 20 feet tall Ripen in May and early June
Requires 150 to 600 hours of chilling Performs best in central and southern Oklahoma More heat tolerant Inset pictures: Top - example of a rabbiteye blueberry (variety unknown); bottom - close-up of foliage of rabbiteye blueberry Discussion: Rabbiteye blueberries grow 5 to 20 feet tall and require 150 to 600 hours of chilling below 45 degrees F. They ripen in May and early June and perform best in central and southern Oklahoma They are more heat tolerant than highbush and they require another variety within their pollination group to be planted nearby in order to get the best fruit set and larger fruit. Refer to OSU Fact Sheet #F-6248 “Blueberry Production for Home Garden” for more information on pollination groups and recommended varieties.
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Southern Highbush Blueberry
Intermediate between highbush and rabbiteye Ripen about 3 weeks earlier than rabbiteye Should perform well throughout Oklahoma Discussion: Intermediate between highbush and rabbiteye in most respects. Ripen about 3 weeks earlier than rabbiteye and should perform well across Oklahoma. Most southern highbush are self-fertile, but two varieties should be planted in order to get better yields.
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Planting and Culture Plant mid-January to late March
Plant two year old plants - 12 to 16 inches in height Plant two or more varieties Set plants approximately 5 feet apart Set the plants without washing soil from roots Mulch at the time of planting and maintain mulch First year apply one application of N in the fall following first season Discussion: Blueberries require special care. They must have an acid soil. They should be mulched. The plants need a cool, damp root zone, while having full sunlight in order to thrive. Refer to Blueberry Production in Oklahoma and to OSU Fact Sheet F-6248 for more information on the planting and culture points listed above.
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Fertilizing Established Blueberries
Ammonium N is better than nitrate N Apply N in small applications once before bloom once after fruit set once in the fall Apply P and K according to soil test Apply fertilizers uniformly within dripline Avoid the base of the plant Discussion: Blueberries require much less N than other fruit corps, excess nitrogen will kill them. Refer to OSU Fact Sheet F-6248 for more information on how much N to apply to blueberries.
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Pruning Blueberries Summer pruning
Removal of broken and diseased branches Size control - prune soon after harvest Winter pruning Removal of dead, diseased and “deranged” and dying canes Thin healthy canes - 6 to 10 main canes per plant Tip remaining canes to maintain convenient harvest height Discussion: Blueberries produce fruit on wood grown the previous season. After blueberries start production, some of the weaker twiggy growth and any diseased or damaged shoots should be removed each year. Large fruit is produced on the more vigorous shoots. New canes emerge from the canes each year. Canes older than 6 years should be removed because they are not very productive. There should be an equal number of fruiting canes, 1, 2, 3, 4, 5, and 6 years of age. Erect varieties need to be thinned in the center, and the spreading varieties may need their drooping branches pruned. “Deranged” canes are those that are growing where they will rub against other canes, canes growing the wrong way through the middle of the plant, and canes that stick out from the plant and make it too wide. Refer to OSU Fact Sheet #F-6248 “Blueberry Production for Home Garden” for more information on pruning of blueberries
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Diseases of Blueberry Introductory slide
Discussion: Blueberries are do not have a large number of disease problems, but some that occur are very destructive.
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Mummy Berry Disease Monilinia vaccinii-corymbosi Blueberry
Berries shrivel and turn pinkish Berries fall to ground and turn brown Favored by cold, wet weather Infects very young tissue Source of inoculum Infected fruit mummies on ground Inset picture: Blueberry fruit shriveled and discolored due to mummy berry disease Discussion: Although mummy berry is not reported as being a major problem in Oklahoma it has the potential of causing considerable damage to backyard blueberries. Infection of young emerging leaves occurs during wet weather. Secondary spores (conidia) are produced in great abundance on the infected leaves and are carried by the wind or insects to open flowers where the ovaries become infected. Prior to harvest, infected berries become light cream-colored rather than normal blue and drop to the ground and form overwintering sclerotia. The sclerotia then serve as a source of infection for the next season.
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Phytophthora Root Rot Phytophthora cinnamomi Blueberry
Early symptoms: Yellowing of leaves Small terminal leaves Lack of new growth Excessive defoliation Inset picture: Blueberry plant expressing symptoms of Phytophthora root rot - Note the excessive defoliation. Discussion: This disease is caused by the soil-borne fungus Phytophthora cinnamomi and although the symptoms listed on this slide are termed “early symptoms” the disease actually initially infects the root system and results in the symptoms listed on the slide. Most highbush cultivars are susceptible to root rot; however, the disease is normally of minor importance unless plants are grown in wet soils brought on by poor drainage. It is not uncommon to observe Phytophthora root rot killing Oklahoma blueberries. Rabbiteye varieties are reported to be highly resistant.
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Phytophthora Root Rot Phytophthora cinnamomi Blueberry
Root system discolored Brown to black epidermis Uniform light brown discoloration of vascular tissue Control: Avoid poorly drained areas Apply metalaxyl soil fungicide Inset picture: Blueberry roots infected with Phytophthora root rot. Note the dark brown discoloration of the root and crown tissues. Discussion: Phytophthora root rot is considered a “minor” disease in much of the eastern U.S., however, in Oklahoma it is known to frequently occur. It is a disease of poorly drained plantings and can be avoided by planting on raised beds or utilizing other methods to improve drainage.
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Stem Cankers Blueberry
Pathogens: Botryosphaeria, Gloeosporium, Phomopsis Occur periodically in Oklahoma Symptoms: Discolored lesions on stems Infected stems eventually wilt and die Inset picture: Left to right: Blueberry stems with lesions (pathogen unknown); stem canker lesions caused by Botryosphaeria; Botryosphaeria stem cankers 3-4 years after infection; Gloeosporium canker and dieback Discussion: There are several fungi that infect blueberry and cause cankers to develop on the stems. Some of the canker disease can result in significant loss of branches resulting in lower fruit production. Some varieties are resistant to Botryosphaeria stem canker and homeowners need to select varieties with stem canker resistance. In situations where stem cankers have become a problem applying fungicides, on a regular spray schedule, will often keep the canker diseases under control.
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Blueberry Disease Control Spray Schedule
Delayed dormant - just before bud break Mid-bloom First post-pollination - about May 25 to June 1 Second post-pollination days after first post-pollination Cover sprays - beginning 7-12 days after second post-pollination, continue as needed on a 7-12 day schedule. Discussion: It may not be necessary to spray blueberries with fungicides unless the patch has a history of fungal diseases such as anthracnose. But, occasionally these diseases do become established and require fungicide applications to insure quality fruit and acceptable yields.
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Blueberry Insects Scale insects Delayed dormant Just before bud break
Dormant pruning Foliar sprays for crawlers Reduced vigor Uncontrolled - death Inset picture: Close-up of scale on blueberry Discussion: Many parts of the blueberry plant can be infested with scale insects. Branches, twigs, and leaves may be covered with clusters of crusty bumps that can be picked off. Some scale are cottony like. Scale may be light or dark colored depending upon specie. This sucking insect causes yellowing of leaves. Branches are sometimes killed by heavy infestations of scale insects. Plants are weakened and lower berry production occurs when large populations develop. Scale are sometimes very inconspicuous and close inspection is required for detection. Control of scale insects can be achieved by using dormant sprays, dormant pruning, and foliar sprays during the crawler stage.
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Blueberry Insects Leafrollers Season-long pest Foliar sprays Removal
Not serious pest Inset pictures: Top - blueberry leaf expressing signs of leafroller damage; bottom - leafroller larva with webbing. Discussion: Leafrollers are caterpillars that are the immature stage of several moth species. They roll leaves up and feed inside. Some species use large amounts of silken threads to tie leaves together. Although plants may become heavily infested, they usually do not affect berry production. Leaf picking and removal can help control this pest. Under heavy infestations a foliar insecticide spray may be needed.
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Blueberry Insects Leafhoppers Stippling Chlorosis Hopperburn
Young leaves Young trees Inset pictures: Leafhopper nymph and adult Discussion: Leafhoppers are yellowish-green to pale green in color in both the adult and nymphal stage. The winged adult is about 1/8 inch long (slightly larger than the wingless nymph). Adults will hop and fly while nymphs will run sideways when disturbed. Damage shows up as cupped yellow leaves. These insects have sucking mouthparts and may be involved in disease transmission. Some species of leafhoppers actually reduce photosynthetic capacity of the plant by their feeding, causing reduced quality and yield. Some leafhoppers have a toxic saliva and cause ‘hopper burn’. Usually these pests are found during the late season and multiple generations can occur. If damage is evident and leafhopper numbers are high, a recommended insecticide may be applied Young trees and immature leaves are most susceptible to leafhoppers. Foliar sprays are sometimes needed for control.
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Blueberry Insects Leaf miners Adult deposits eggs
Larvae feeds on foliage Post pollination Cover sprays Inset pictures: Leaves expressing signs of leaf miner damage; middle - leaf miner larva; bottom - leaf miner adult Discussion: Leaf miners damage leaves by leaving trails that enlarge into blotches on leaves. They feed inside the leaf between the upper and lower surfaces. During midsummer, the upper surfaces are eaten giving the leaves a lacy appearance. Many of the leaves may drop off after turning brown. Leaf miner is a term that covers the larvae of flies, moths, beetles, or sawflies. Because of their feeding habits, leafminers are protected inside the leaf. Control can be difficult and where history indicates heavy pressure, a post pollination spray and subsequent cover sprays may be needed to control this pest.
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Blueberry Insects Cherry fruitworm Eggs laid on fruit
Larvae bore into fruit Brown trails Distorted fruit Well-timed sprays Inset pictures: Top left - cherry fruitworm larva; top right - cherry fruitworm adult moth; middle - fruitworm damage on blueberry fruit; bottom cherry fruitworm larva inside fruit Discussion: This pest can be serious and growers should watch for its appearance. Damage consists of shriveled distorted fruit that is full of sawdust-like material. The adult moth is grayish black and has a wingspan of about 1/2 inch. Eggs are almost impossible to see because of their small size and color. They hatch and the larvae bore into the fruit very quickly. Larvae reach about 1/2 inch in length. They feed within a berry until about half grown and then tunnel into another berry touching it without exposing itself. Once the fruit is infested, there is no way to kill the worm inside with insecticide applications, so handpicking and destruction of infested fruit is recommended. Well-timed sprays (immediately after bloom and before the berries reach 1/4 inch) will help prevent entry of larvae into fruit.
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Blueberry Insects Aphids Sap feeders Undersides of leaf
Distorted leaves Honeydew Inset pictures: Top - aphid damage on blueberry foliage; bottom - aphids on blueberry leaf Discussion: Aphid infestations can become serious with high populations. These tiny insects, often called plant lice, are generally found on the lower sides of leaves. Many species of aphids can and do attack fruit crops. Color varies with species and ranges from pale yellow to dark green to reddish brown to purple. With large numbers, dwarfing of the plant and honeydew accumulations frequently result in smut formation. Light infestations can be tolerated and in fact may contribute to the beneficial population. Chemical selection is important in aphid control. Avoid using carbaryl early in the season which contributes to aphid outbreaks. A dormant spray will deter or limit aphid buildup in the early season. A prebloom spray with a superior summer spray oil also limits this pest. Cover sprays should keep numbers of aphids at an acceptable level during the remainder of the growing season. Insecticidal soaps have been used successfully against this soft-bodied pest.
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Blueberry Insects Plum curculio Early season pest Attacks fruit
Crescent scars Fruit drop Inset pictures: Top - plum curculio damage on blue berry fruit; bottom - adult plum curculio feeding on blueberry fruit Discussion: The damage caused by this pest includes: crescent-shaped scars, internal injury by larvae, premature dropping of fruit, and feeding punctures in the fall. These snout beetles migrate from woodlots for periods of up to 6 weeks after bloom with the greatest migration occurring within a 14-day period after petal fall. After larvae feed and pupation occurs the plum curculio adult emerges and feeds before cold weather forces them into hibernation quarters. This pest can be difficult to control and needs a full dosage of an effective pesticide. Adult plum curculio are dark brown beetles about 3/16 inch long with whitish to gray patches and has three pairs of humps on its wing covers. The beak or snout is about 1/4 as long as the body length. The larvae are yellowish white with a well-defined brown head capsule and no legs. A fully developed larva is about 1/4 inch in length. Fruit drop is common when this pest is present. Chemical control should begin as a post pollination spray and continue through late May to early June with cover sprays.
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Blueberry Insects Blueberry maggot Most important pest
Larvae feed inside berry 1 per berry Flies emerge in June Most severe Following cold winter Wet conditions at harvest Spray every 10 days when flies begin egg laying Inset picture: Blueberry maggot adult (lower left), blueberry maggot larva(upper right) Discussion: Blueberry maggots are the most important pest of blueberries. Ripening blueberries are soft and mushy and leak juice when handled. Inside the berry, a developing, white, tapered maggot can be found when blueberries are infested with this pest. The adult is a fly that lays eggs just under the surface of the fruit. Emergence of adult flies and egg laying usually occurs in June. Infestations are most severe following cold winters and when harvest is delayed due to wet conditions. Watch for this pest and destroy any infested berries. Harvest frequently and spray when needed. One generation per year makes control easier than for some other pests.
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Blueberry Harvest Limited production first year
Mature plant produces 14 to 23 pints depending on pruning and variety Cluster does not ripen evenly = harvest individual berries Ripe berry - uniform blue Harvest every 5 to 7 days Inset picture: Blueberry fruit Discussion: In Oklahoma blueberries begin to ripen in late May and continue into late June. The berries are ready to harvest after they have turned a uniform light blue. Redness indicates the berry is not fully ripe. Unlike grapes the berries in a cluster do not ripen evenly, therefore individual berries are harvested. This requires repeat harvesting every few days. By planting several varieties, harvest can be extended over an 8- to 9-week period. Once the berries begin to ripen, harvest every 5 to 7 days. Refrigerate harvested berries, but do not wash berries until ready to use them. Blueberries keep well in the freezer to be used in baking and cooking. Rinse frozen berries in cold water just before using.
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Acknowledgements Appreciation is extended to the following for the use of some images contained in the Backyard Fruit Production Program: Michigan State Cooperative Extension Service North Carolina Cooperative Extension Service Ohio State University Cooperative Extension Service Oregon State Cooperative Extension Service Texas Cooperative Extension Service West Virginia Cooperative Extension Service
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Backyard Fruit Production
Program developed by: Oklahoma Cooperative Extension Service Oklahoma State University Susan Gray, Extension Educator, Horticulture Phil Pratt, Area Extension Specialist, Plant Pathology Jim Shrefler, Area Extension Specialist, Horticulture Bill Stacey, Area Extension Specialist, Entomology
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