Presentation on theme: "Advanced Tomato Workshop"— Presentation transcript:
1 Advanced Tomato Workshop Common Tomato ProblemsChris Becker
2 Insect, Disease, or Disorder? Tomato Problem Quiz AnswersInsect, Disease, or Disorder?
3 What is a Disease?A plant disease is usually defined as abnormal growth and/or dysfunction of a plant. Diseases are the result of some disturbance in the normal life process of the plantDiseases may be the result of living and/or non-living causes.
4 Diseases Abiotic Biotic Abiotic diseases are caused by non-living environmental conditions such as frost, hail, and chemical burn, nutrient deficiencies.Biotic diseases are caused by living organisms.Biotic causes of disease include fungi, bacteria, viruses, phytoplasmas, nematodes, and parasitic plants.
6 Disease SymptomsSymptoms of disease are the plant’s reaction to the causal agent.Blight – A rapid discoloration and death of twigs, foliage, or flowers.Canker – Dead area on bark or stem, often sunken or raised.Chlorosis – yellowing – Chlorosis is so generic that without additional details diagnosis is impossible.Decline – Progressive decrease in plant vigor.Dieback – Progressive death of shoot, branch or root starting at the tip.Distortion – malformed plant tissue.Gall or gall-like – Abnormal localized swelling or enlargement of plant part. It could be caused by insects, mites, diseases, or abiotic disorders.Gummosis – Exudation of gum or sap.Leaf distortion – The leaf could be twisted, cupped, rolled, or otherwise deformed.Leaf scorch – Burning along the leaf margin and into the leaf from the margin.Leaf spot – A spot or lesion on the leaf.Mosaic – varying patterns of light and dark plant tissue.Necrosis – dead tissue – Necrotic areas are also so generic that without additional details diagnosis is impossible.Stunting – lack of growth.Wilt – General wilting of the plant or plant part.Witches broom – Abnormal broom-like growth of many weak shoots.Insect feeding injury is also a symptom used in diagnosis, but not a symptom of disease.
7 Disease Signs Signs are the actual organisms causing the disease. Conks – woody reproductive structures of fungi.Fruiting bodies – Reproductive structures of fungi; could be in the form of mushrooms, puffballs, pycnidia, rusts, or conks.Mildew – whitish growth produced by fungi composed of mycelium.Mushrooms – fleshy reproductive structures of fungi.Mycelium – thread-like vegetative growth of fungi.Rhizomorphs – Shoestring-like fungal threads found under the bark of stressed and dying trees caused by the Armillaria fungi. They may glow in the dark!Slime Flux or Ooze – A bacterial discharge that oozes out of the plant tissues, may be gooey or a dried mass.Spore masses – masses of spores, the “seeds” of a fungus.Insects and/or their frass (excrement) are also signs, although not signs of disease.
8 #1 Aphids Insect Pests Have piercing, sucking mouthparts; physical damage not always apparentUsually found on underside of leafThey can reproduce asexually.Color varies in speciesProduce honeydewPreventionInsecticides
9 #2 Fruit Cracking/Splitting An Environmental DisorderCaused by rapid fruit developmentand wide fluctuations in wateravailability to the plant.Mature ripening fruit are mostsusceptible, especially when thereis a very dry period followed byheavy rainfall.Severity varies greatly by variety.Preventionincorporate organic matter, usedrip irrigation, apply mulch
10 #3 Septoria Leaf Blight A Fungal Disease Causes numerous small ( about 1/8" to 1/4" in diameter) brownspots that develop light tan towhite center as they ageSimilar to early blight. Attacksolder leaves – turns yellow,brown, then withers and dies.Wet humid conditions favor thedevelopment .It usually appears after plantsbegin to set fruit.Preventionuse mulch, apply fungicide, limitwetting foliage / overhead watering
11 #4 Herbicide Damage Herbicide Damage Symptoms include downward rolling of leaves and twistedgrowth. In addition, stems mayturn white and split; fruit may bedeformed.Depending on the level ofexposure, the plant may or maynot survive.PreventionDo not apply 2-4-D like herbicidesnear the gardenAvoid driftPrevent contamination by keeping herbicide spray tanks separate from insecticide& fungicide spray tanks.
12 #5 Glyphosate Injury Herbicide Damage White/Yellow discoloration at thebase of the youngest leaflets.A result of spray drift to the stemof the plant and/or applicationduring a windy day.Herbicide on stem becomestranslocated to the upper leaves.1/50th to 1/150th rate can do thistype of damage.PreventionUse a shield to limit drift.Cut off the leaves and observe theplant
13 #6 Southern Blight A Soilborne Fungal Disease Causes yellowing of leaves andwilting of infected plants.The stem at the soil line appearssoft and sunken (cankered) andturns brown to black.Under moist conditions, a whitefungal growth occurs on the lowerstem near the soil surface.Favored by moist conditions andhigh temperatures above 85 °F.Preventioncrop rotation, soil solarization,deep plowing
14 #7 Fusarium Wilt A Soilborne Fungal Disease Invades the roots, plugs-up thewater conducting vessels, causesyellowing and wilting of leaves.Initially causes a yellowing andwilting of lower leaves on a singlebranch.Whole plant eventually wilts anddies.Preventionuse resistant varieties, croprotation, soil solarization.
15 #8 No Tomatoes Mostly an Environmental Disorder Plants sometimes drop their flowerswhen night temperatures are lowerthan 55°F.When night temperatures above70°F, flower production andpollination are reduced.Favorable night range for tomatofruit set is between 58 and 68°F.Very hot daytime temperaturescoupled with drought is a cause too.May occur due to excessive nitrogen.PreventionUse heat resistant varieties.
16 #9 Tomato Fruitworm Insect Pest Also known as Corn Earworm Caterpillar color varies from lightgreen to reddish-brown.Usually has a broad dark stripewith a light stripe on the body.Feeds on stem end, enteringinside the fruit of green tomatoes.Feeding damage leads to wateryand wormy fruit.PreventionHand RemoveInsecticides
17 #10 Blossom End-Rot A Nutrient Disorder Caused by a Calcium Deficiency,Due to improper soil pH, above orbelowInsufficient calcium in soilAggravated by changes in soilmoisture – too dry or too wetPreventionspray calcium nitrate for temporaryrelief, take a soil test, add lime,keep soil moisture consistent.
18 #11 Catfacing A Physiological Disorder Misshapen ugly fruit. Cold weather at the time ofblossom set distorts and killscertain cells that should developinto fruit, resulting in thedeformities.Most often observed among first-formed fruit.Common in the large-fruited“beefsteak” type tomatoes.Preventionnone
19 #12 Zippering A Physiological Disorder A thin longitudinal scar from thestem scar to the blossom end.Series of transverse scars whichresemble a zipper.This defect happens when theflower anthers fuse to the ovarywall of developing fruitOccurs most commonly when fruitset takes place in cool weather.Varieties can vary in theirsusceptibility to this malady.PreventionNone
20 #13 Stinkbugs An Insect Pest Feed with piercing-sucking mouthparts which cause whitish-yellow corky spots underneath theskin of the fruit.On green fruit, damage appears asdark pinpricks surrounded by alight discolored areaCommercially, this damage isserious because they render thefruit unmarketable.PreventionInsecticides
21 #14 Early Blight A Fungal Disease Begins on older lowers leaves by turning them yellow.Leads to irregular spots thatenlarge to ½ inch in diameter withconcentric rings and a yellow halo.Plants appear to “fire-up” fromtheir baseEarly season pest; warm, wetweather favor its developmentPreventionuse mulch, apply fungicide, limitwetting foliage / overhead watering
22 #15 Tomato Spotted Wilt Virus Virus disease spread by thripsInfected plants are stunted, maydie slowly.Dark ring spots form on leaves.Terminal leaves stop growing,become distorted and have a palepurple/bronze appearance.Fruit exhibit “real cool-looking”ringspots.PreventionRemove suspected and infectedplants immediately, control insects,use resistant varieties
23 #16 Armyworms Insect Pest Caterpillar color varies from dull green to black.Older larvae have a broad, light-colored stripe along the side ofthe body.Feeds primarily on leaves but willattack fruit making a single orgroup of holes or depressions.Damage is typically superficial butcould lead to fruit to rot.PreventionHand RemoveInsecticides
24 #17 Leaf Roll A Physiological Disorder Edges of the leaves roll upward and inward.High temperatures, prolongedperiods of wet soil conditions,and drought may promotesymptom development.Symptoms are most commonwhen plants have a heavy fruit set.Associated with varieties having aspecific gene that favors this condition.PreventionVariety Selection, Irrigation
25 #18 Cutworms An Insect Pest Active only at night and remain buried below the soil surface nearfood plants during the day.They emerge to feed at night andoften cut seedlings or smallstems, causing the plants to fallover.PreventionInsecticides, remove grass andweeds, plow the soil well inadvance of planting, use paper orplastic "sleeve" over the plant toprotect the stem.
26 #19 Sunscald A Physiological Disorder Initial symptom is a whitish, shinyarea that appears blistered.Occurs on green tomato fruitexposed to the sun.Injury is more serious duringperiods of abnormally hightemperatures.The killed tissue is quicklyinvaded by secondary organismsand the fruit decays.PreventionControl foliar diseasesAvoid heavy pruning
27 #20 Bacterial Spot and Speck Bacterial DiseasesIntroduced on transplantsAttacks leaves and fruitFavored by warm, wet conditionsLeaf spots can be irregular andraggedFruit spots can be raised orscabbyPreventionUse disease-free transplants
28 #21 Tobacco Hornworm Insect Pest Large, smooth, green caterpillar of the Carolina Sphinx moth.Mature larvae measure 3½” inlengthHas seven or eight conspicuouswhite V-shaped markings downeach side and a prominent spike(horn) on its rear endFeeds on the leaves, stems andfruit of tomato plantsPreventionHand remove, insecticides, plantdill a trap crop.
29 #22 Adventitious Roots A Physiological Disorder These are adventitious roots oraerial roots which would grow intonormal roots if placed in contactwith the soil.They emerge as a result of stress,particularly water-related stress.Determined by cultivar, weatherconditions and culture.PreventionMaintain moisture, moundcompost around root initials onthe lower part of the plant.
30 #23 Thrips Tiny Insect Pests Prefer to feed in flowers, but also occur in flower and leaf buds andon leaves.Feeding on foliage may cause abronzing or silvering of foliage.Eggs inserted in fruit causesdimpling, and the infested areamay appear white.Thrips are also vectors of tomatospotted wilt virus.PreventionInsecticides
31 #24 Whiteflies An Insect Pest Adults are very small, white and moth-like; 1/16th inch long.Feed underside the leaves on plantsap.Usually noticed during mid to latesummer.Numbers are usually not sufficientto cause damage to plants.They do excrete honeydew andmay cause sooty mold.PreventionInsecticides, sticky traps
32 #25 Spidermites An Arachnid Pest They damage plants by inserting their stylet mouthparts intoindividual plant cells andwithdrawing cellular liquids andcontents.Damaged plants take on a bronzedappearance.Affected leaves eventually die andturn brown.Tends to be hot weather pest.PreventionHorticultural oils and soaps
33 #26 Bacterial Wilt A Soilborne Bacteria Disease Most commonly found in low, wetareas of fields.Plants wilt and die rapidly withoutyellowing or spotting of thefoliage.It invades and gradually blocksthe vascular tissue (the food- andwater-conducting vessels justbeneath the epidermis).The pith will turn brown andsometimes become hollow.Preventioncrop rotation, soil solarization.
34 #27 Nematodes Microscopic wormlike animals found in the soil – 1 mm in length.Damage plants by feeding onroots, impairing its ability totake up water and nutrients.Cause stunting, leaf yellowing,loss of plant vigor, reduction inyields, and wilting.Causes distinct swellings or gallson roots.Non-uniform distribution ofsymptomatic plantsPreventionSoil Solarization, Crop Rotation
35 #28 Flea BeetleFlea beetles are tiny black beetles that jump when disturbed.Overwinter as adults and begin feeding in spring.Feed on the undersides of leaves causing small holes or sunken pits.Mostly a problem on new seedlings, and if left unchecked, can cause significantPreventionInsecticides
36 #29 Leaf-footed bugInsect pest that feeds on tomato plants during the adult and nymph stage.Overwinter as adults and begin feeding in spring.Congregate and feed together during nymph stages.PreventionInsecticides
37 #30 Buckeye Rot Caused by the fungus phytophthora parasitica. Starts as a grayish green or brownspot on fruit that has come intocontact with soil.Light and dark brown concentric bands appear in the affected area. This firm, leathery rot is characterized by a smooth surface and lack of sharply defined margins.PreventionMulch, prevent fruit from touching the soil.