Presentation on theme: "Vegetable Production Introduction:"— Presentation transcript:
1 Vegetable Production Introduction: International rate of increase in the population is about 2% →2× each years which is now about 7 Billion. This means that:Demand for food is increasing continuously while cultivated area or involvement of the area (old and new) is not proper with the increase in demand. Soil of very good properties is suitable for all sectors, so land involved in agriculture is of very low characteristics →which will increase the cost of cultivation. Total area is about 10% of the total.Rich countries can either produce or import even if with high cost, while poor or developing countries are suffering from Hunger situations and malnutrition (in Asia, Africa, and Latin America).Ref.: Table 1 and 2
2 The ratio of differences between rich and poor countries is about 20 years in life expectancies . متوسط العمرThis is because of variation in Energy requirement/person and availability of fruits, vegetables (tubers, and or fruit nuts) which are important sources of high nutritional requirements (minerals, vitamins, proteins, starches, fats, and sugar), plus their importance for crude fibers → commercial sector → which is not possible by poor import or cultivate.One of the main reasons for hunger is the unbalance situation between number of people/km² area, and the arable land used for production. For example, Asia had reached saturation per km² → which means low food supply and low new land to be added, because of increasing in the number of people.Ref.: Table 1.1 and 1.2
3 Vegetables, including melons 70,623 Tomato 40,414 Cabbage 29,961 Table1: Worldwide Production of Vegetables in 1993 in descending order.Production (1000MT)RemarksVegetableCategory 1:603,195Roots and tubers288,183Staple Foodغذاء اساسيPotato123,750Sweet potato153,628Cassava28,126نوع بطاطا حلوةYams13,977Carrot1,137ArtichokeCategory 2:465,457Vegetables, including melons70,623Tomato40,414Cabbage29,961Onions (dry)
4 Cantaloupes, and other melons 27,063Watermelons18,326خيار ومخللCucumber and gherkins12,976Cantaloupes, and other melons10,630Green peppers8,682Eggplant8,019قرعPumpkin, squash, gourds7,624Garlic6,754Cauliflower4,602Green peas3,087Green beans
5 * Vegetables (except roots and tubers) including carrot and melons. Table 2: Major Vegetable Producing Countries*.Production (1000MT)Country125,509China60,010India32,660United States18,468Turkey13,035Italy10,450CIS**9,945Spain7,474Egypt5,651Mexico5,495Nigeria465,457Total worldwide* Vegetables (except roots and tubers) including carrot and melons.** Commonwealth Independent States
6 Vegetable: A horticultural food crop, most grown as annuals and few as perennials. Most are herbaceous, edible part is either roots, stems, leaves, immature floral part, immature seeds and immature or mature fruits, where the edible part is highly rich with water which means the storage period is relatively short even under proper conditions, and can be eaten either raw or cooked.
7 Population in agriculture 0.21ha(0.5acre) 0.56ha(1.4 acre) Table 1.1. Some comparisons of developed and developing regions of the world.DevelopingDeveloped¾ of total¼ of totalPopulation2-3% per year1.5% per yearPopulation growth60% (17-93%)13% (2-48%)Population in agriculture0.21ha(0.5acre)0.56ha(1.4 acre)Arable land per personFood energy:2280 cal3370 calTotal/person/day90%70%From plant sourcesProtein:58 g99 g21%56%From animal sourcesSource: FAO data (1979).low food supply in developing countries could be also related to the use of well fertilized land for export, activities. In addition to what mentioned before.
8 Table 1.2. Food producing capacity of some countries in relation to population density and arable land in 1979Arable land a(ha/person)Population density(people/ km²)Country2.972Australia1.873Canada0.9410Argentina b0.8624United States12U.S.S.R.0.445Congo b0.3235Mexico b0.24228India b0.17194Italy0.12233United Kingdom0.11166Philippines b0.10102China b0.0741Egypt b0.06413Netherlands0.04312Japan
9 Source: FAO data (1979).a Arable land:(a) If greater than 0.8 ha/person, food supply usually adequate; export of surplus.(b) If in range of ha/person, country is 80% to completely self-sufficient. (c) If less than 0.4 ha/person, diet high in food of plant origin; import of food for adequate diet.b Developing nations.
10 Importance of Vegetable The intake of proper nutrients is necessary for well being.Proper food means different kinds of food with proper balance and optimal amounts.The required amount of nutrients can vary with sex, age, size of the body, activity and environmental conditions.The term under nourished means lack or inadequate caloric intake.The term malnourished means lack of minimum daily intake of proper food that including essential amino acids, vitamins, minerals and others.Both malnourished and undernourished can lead to diseases as marasmus disease, also it can increase susceptibility to infections and diseases, stunting of child’s growth even physical or mental →so it leads to reduction in intelligence level.
11 Importance of food components: Ref.: Table 3 1) Water: for dissolving minerals, maintain the osmotic balance in cells and drive out the metabolic waste. Daily intake is 1100ml from food and 1100ml from drinks and 250ml from metabolic water = 2450ml.Daily output of water is 1350ml as wastes and 1100ml as evaporation, and losses from skin and lungs, so the total daily output is 2450ml.- Metabolic water can be derived from carbohydrates (CHO), proteins, and fats, where:1g of starch→ 0.6g of H2O1g of protein→ 0.41g of H2O can be obtained from vegetables1g of fats→1.07g of H2O
12 2) Energy: all foods released energy as they are broken in the body 2) Energy: all foods released energy as they are broken in the body. Man needs about kcal/day, where:1g of CHO→4kcal as metabolic energy1g of Fats→9kcal as metabolic energy1g of Protein→4kcal as metabolic energyCan be obtained from vegetables3) Carbohydrates (CHO): main CHO compounds in plants are starch, sugar (sucrose, glucose, fructose), for example, sun flower and onion are rich in fructose.4) Lipids: fats and oils: adequate diets should have almost 15% of total calories derived from lipids. Fats of vegetables are generally oils while those of animal are solids. Vegetable fats are of less cholesterol in the blood. Also blood pressure and heart diseases are related to excess intake of fats (animal fats).
13 5) Proteins and amino acids: for building of body and enzymes formation which carry out the body functions.The 8 essential amino acids are not synthesized by body cells, so they are taken from food (plant and animal).Protein quality: present of amino acids in proper proportion so as to be utilized effectively essential لأن غياب واحد يمنع تكوين الأخرNet protein utilization: % of amino acids ingested as protein and retained in the body as protein. Vegetables show 50-70% متوسطهProtein efficiency ratio: weight gained/unit of protein fed which is for vegetables =2.0Protein malnutrition can cause kwashiorkor = nutritional disorder cause brain damage for ages from 6months-6years old.Ref.: =Tables
14 6) Vitamins: they are potent organic substances, need for normal body function. Ref.: Table 4Fat-soluble vitamins: that can be stored by body.Vitamin A: which is essential for vision in dim light and it’s deficiency cause abnormal dry skin. Highly found in green plants.Vitamin E: which acts as antioxidant, it’s deficiency affects on the reproductive mechanism, but it's low in vegetables.Vitamin K: which is important in coagulation of blood, found in fresh dark vegetables as spinach.Daily intakes of vegetables is greater than animals
15 b. Water-soluble vitamin: can’t be stored by body in a significant amount, so we need continuous food sources.Vitamin B1 (Thiamine): prevents Beriberi ضعف, cofactor in CHO metabolism. It’s deficiency prevents normal metabolism of pyruvic acid that come from CHO metabolism → brain and nerve which depends on CHO = as a source of energy will be affected negatively. Vegetables are good sources of B1.Vitamin B2 (Riboflavin): it is a part of enzyme system to convert the food to chemical energy. Leafy vegetables are good sources even rich.Vitamin C (Ascorbic acid): prevents scurvy مرض الاسقربوط =تورم اللثة ونزف الدم, it’s deficiency can cause anemia, poor wound healing and connective tissue formation. Green vegetables are high in vitamin C as pepper while tomato juice contain from 15-20mg (good), but potato has low vitamin C content, which by using sufficient amount → can be good source.
16 Vitamin B6 (Pyridoxine): has a role in nervous tissue metabolism and in anemia. Vegetables are high in this vitamin.Folic acid (Tetra hydrfolic acid): important in nucleic acid and protein syntheses of the cell. Spanish, broccoli, cabbage and lettuce are good sources.7) Minerals (Table 5): They are required to support human biochemical processes by serving structural and functional roles, they are divided into two categories:a. Macro-elements units: including:Na, K, and Cl: important in maintaining osmotic balance of body fluid.Ca, Mg, and P: important in blood and skeletal system, P also involved in many enzymatic reactions.S: important in protein building throughout it’s role in enzyme system.Fe: important in hemoglobin formation of the red blood cells.
17 b. Microelements units: including: I: for thyroid activity.Cu: for tyrosin activity, it’s lack block Fe metabolism and cause anemia.Zn: involved in at least 8 enzymes systems.Co: in vitamin B12 activity (anemia prevention).Mn: cofactor in many enzyme reactions.F: important to prevent dental decay.All these can be obtained from vegetables.
18 Table 3: Proximate Composition (per 100g edible portion) of some important vegetables. CHO(g)FatProtein (g)Moisture (g)Energy (kcal)Common Name220.127.116.112.425Bitter ground4.00.31.492.724Brinjal (eggplant)5.41.3Cabbage1.293.422Capsicum18.104.22.168Carrot38.10.759.4157Cassava5.22.791.027Cauliflower22.214.171.1244.117Celery0.496.318Cucumber7.11.990.132French bean29.86.362.030Garlic2.595.114Lettuce3.595.2Muskmelon6.489.635Okra11.186.850Onion
20 Table 4: Vitamin Content (per 100g edible portion) of some important vegetables. (mg)B3NiacinB2Riboflavin (mg)B1Thiamine (mg)Vitamin A(IU)Common Name880.50.090.07416Bitter ground120.90.110.04244Brinjal (Eggplant)470.30.350.05130Cabbage1280.06900Capsicum30.611000Carrot250.10Cassava780.760Cauliflower90.03240Celery70.2Cucumber190.08600French bean130.40.23TraceGarlic8Lettuce26558Muskmelon
21 130.60.100.07172Okra110.40.010.08TraceOnion2126.96.36.199640Peas171.224Potato510.208100Spinach210.068800Sweet Potato230.70.04900Tomato70.20.03590Watermelon150.80.1YamIU: Vitamin A is formed of Isoprene units each has 5 carbon atoms.
22 Table 4.2: Minimum requirements of essential amino acids: national research council (g/day) Infant of 15lb wt.Young female adultYoung male adultAmino acid1.050.621.10Leucineª0.830.450.70Isoleucineª0.720.500.80Lvsineª0.610.31Threonineª0.150.160.25Tryptophaneª0.740.65Valineª0.320.29Methionineª0.22Cysteine0.63Phenylalanineª0.90Tryosine0.24Histidineª Essential amino acids.
23 Phenylanine plus tryosine Methionine plus cystine Table 4.3: Essential amino acid composition of some vegetables in comparison to hen’s egg and the limiting amino acid determining protein score.(% of FAO hen’s egg)ValinePhenylanine plus tryosineMethionine plus cystineLysineLeucineIsoleucineThreonineTryptophanName687149 ª816447 ª5888Collards ملفوف34 ª49745170Kale لفت7567 ª9687102Spinach736240 ª8357667767Potatoes10163 ª6592109Sweet potatoes9437 ª116988685Common beans6921 ª9995Broadbeans8252 ª60Cowpeas28 ª8053Lentils
24 ª Limiting amino acids. b based on average figures. 868557 ª10494889359Lima beans816431 ª107103846146Mung beans779146 ª1157667Peas8940 ª9892Lima beans (green)566334 ª7471697252Peas (green)(g/100g protein)FAO hen’s egg bSource: Kelley (1972)ª Limiting amino acids. b based on average figures.
25 Table 5: Mineral Content (per 100g edible portion) of Some Important Vegetables. Iron(mg)PhosphorusCalciumCommon Name1.87020Bitter ground0.94718Brinjal (Eggplant)0.42949Cabbage0.7229Capsicum3637Carrot4050Cassava1.15625Cauliflower0.32839Celery1.510Cucumber0.844French bean1.331030Garlic2.02635Lettuce
27 Factors affecting amounts of nutrients in vegetables: Genetic make up of plant: under same growing conditions → you can see wide range of nutrient content in the same population. So selection and breeding program can be used to improve nutritional content of various vegetable spp.Environmental conditions:a. Seasonal factors: temp., moisture, and light, but excess or shortage of any factor negatively affects on nutrient content.b. Atmospheric conditions and composition of toxicants and pollutants, also affects negatively on nutrient content.c. Soil factors: chemical and physical properties of soil, and soil moisture content.d. Cultural practices: fertilization, pests, diseases, weeds, competition and maturity aspect.
28 3) Losses during and after harvesting: A . Harvest: volume of losses varies depending on spp. it self and its ability to resist braising and brake of cells. Mechanical induces more damage than hand harvest also transport could cause damage.B .Holding and storage prior to processing: time and temp. can affect nutrient value. Content of Vitamin C is an index for proper storage condition since it is very labile.C .Washing prior to processing: if you use recycled water which gets warmer and if you use detergents → some soluble substances can be leached and contamination with trace metals can occur while pesticides residues can be removed (non systemic pesticide).D .Peeling and chopping: removal of peel even mechanical or by using soda → nutrients concentrated in skin can be removed especially Vitamin C because by oxidation which follows peeling or chopping or from tomato since concentrated under skin.
29 E .Blanching: exposing vegetables to steam or hot water to inactivate enzymes which may deteriorate the product. By this technique, water soluble vitamins and minerals can be exposed to losses.F .Processing: done by:1) freezing; 2) dehydration; 3) canning; or 4) pickling. Thermal processing can induce major loss.G . Packaging and storage: depends on container to be used, storage temp., and duration of storage temp., and duration of storage. Low or no O2 by N2 replacing conditions, vacuum, low temp. and darkness to keep low temp., and no chlorophyll pigments, are best for nutrient retention. So, as temp. and/or storage time increase quality will decrease.
30 Vegetables can be grouped as a source of nutrients into: High CHO as: white potato, sweet potato, sugar beet, sweet corn, dry beans, and cassava.High in oils: legume seeds, and mature vegetables seeds.High in proteins and amino acids: beans, peas, most leafy vegetables (cruciferous vegetables= Brassica spp.), and sweet corn.High in Vitamin A: carrot, sweet potato, cucurbits, pepper, green leafy vegetables, green beans, and peas.High in Vitamin C: crucifers, peppers, tomato, melon, most leafy vegetables, immature seeds of beans, and white potato.Rich in minerals: most leafy vegetables especially crucifers and root crops.
31 So by under standing nutrient content of vegetables, it is possible to depend on plants when you take crops rich in protein in sufficient amounts.So, what are the suggestions to improve vegetables situation?A) Increase of food supply :byIncrease production: it is now about 2% per year to face the population growth, 20% from new areas involved and 80% due to Technology. As: new CVs, good cultural practices, fertilization, irrigation, plant population and regulators. This means better sustainability.Development of new food forms from other resources using by-products, wastes and residues, (hydroponic) .
32 3)Increase the efficiency of nutrient production By eliminating animals from food chain a- plant →animal (excluded) →manEfficiency of land production will increase if we produce directly for human consumption, and concentrating on those that substitute low consumption from animals (valuable food = fats + protein of animals).Ref.: Figure 1.1.b- Selection of crops that produce highest quantity of nutrients as for example efficiency of producing the 8 essential amino acids to improve the nutritional status.Ref.: Figure 1.2
33 4)Multiple cropping: greater than cropping cultivation in one year a- sequential cropping: growing of two or more crops in a sequence/year, could be done by soil less cultivation.b- Inter cropping: growing of two or more crops simultaneously on the same land-either mixed or in alternative rows or strips.c- Ratoon cropping (to save all the time): cultivation of regrowth parts of the same crop after harvest (suckers and adventitious shoots).d- Relay cropping: the simultaneous growth between two or more crops, occurs in part of the growing period of each crop, normally the 2nd crop is seeded or transplanted when the first crop reaches the productive stage, as cucumber then tomato.
34 B) Improving the world vegetables: National Improving efficiency, distribution, and conservation (in the same country) by cooperatives and institutions. Since single farmers can not if prices at producing sites are low, and costs of transport to areas that they need are high, so they can not control diseases, rodents, … during handling to decrease losses.2) Reducing losses and wastes during all production stages by: 1) Protect against diseases, insects, using immune cultivars; 2) Stop erosion and water wastes.3) Taking care of subsistence crops as much as the valuable exportable crops to achieve stability.4) Improving the use of wasted organic parts of vegetables.
35 C) Improving international trade of vegetables, since the nature of vegetables is highly perishable → trade activity is very low.The concentration should be directed towards processing, dehydration, freezing of products for longer distances, and improving means of transport either by air or seas, and using refrigerators for national transport of long distances.- Also demand for vegetables increase during winter which can be by producing in tropical and subtropical regions, and forcing the vegetables. This needs programming, grading, and improving the quality of production. (Intrinsic and phenological characters).
36 Figure 1: Possible routes from production to consumption of vegetable. (from Ref. 5.)StorageHome PreparationConsumption
38 Fig. 1.2.: Efficiency of crops and animals in producing the essential amino acids on an area basis Vegetables are among those that produce the highest quantity of amino acids which also occurred in short period of time
39 In Jordan, major production areas of vegetables are: Dry lands: were annual precipitation rate is 300mm or more, mainly in Irbid, Amman, Maa’daba, and Balka. That share with about 4.5 million J.D. of the total income, and represents about 1.6% of the total cultivated area. The production is changeable in relation to rainfall quantity.Main crops are deep rooted ones as: tomato, okra, sweet melon, and snake cucumber. It is characterizing with low production because of: 1- Low plant density; 2- Rare treatments; 3- Low yielded cultivars are used. Since expected profit is low.2) Irrigated up lands: Beside lands irrigated by springs or by ground water, even protective and open field, both share with about 155 million J.D. of the total income, and represents about 53.8% of the total cultivated area. Mainly in Mafraq, Zarqa, Maa’daba, and Baqa.Main crops are: tomato, eggplant, cucumber, cauliflower, sweet melon, and squash. Average yield is relatively low except when area is covered with plastic houses, because of low experience to fertilization, irrigation and pest or diseases management.
40 3) Jordan Valley Area: From north to south, the vegetables are planted from August to February, there are two planting times; in August and in Spring.In the southern regions spring planting time is of high risks because of many factors:1) Water: it is a limiting factor;2) Annual precipitation is decreasing from year to year;3) High labor cost which represents about 50% of the total input cost;4) Mechanization is not effectively used;5) Land is divided to 30 donum areas between owners which means low technology implementation.Main crops during fall season are: tomato, potato, onion, squash, eggplant, and others as pepper, beans, and cucumber showing about 100,000 donum of cultivated area.Main crops during Spring are: Jews mallow, tomato, potato, musk melon, eggplant, onion, okra and water melon showing about 45,000 donum of cultivated area.
41 Factors influencing vegetables growth: 1- Climatic factors : Interaction of temp. x moisture x wind x solar radiation = atmospheric condition per period of time and summation of these atmospheric conditions, which determine the climatic conditions for many years, also,2- Also, Soil conditions that depends on climatic factors, is another factor.For both climatic and soil factors appear the adaptation of plant spp. and ability to grow.
42 1) Climatic factors: Temperature. Moisture or precipitation rate Light WindCO2 concentrationA. Temp.: limits growth and distribution of plants, it is a result of solar energy that equals 2g cal/cm²/minute. Temp. distribution: equatorial zone is the hottest, while polar zones are the coldest with difference in solar energy received leading to seasons formation/year (summer, Autumn, Winter, and Spring).- There is a 45ْC variation between winter and summer, while in equatorial is just 3ْC.- Variation over continents is higher than that over oceans and seas because of larger heat capacity of water than soil.
43 - Day temp is higher than night temp. where maximum temp - Day temp is higher than night temp. where maximum temp. is in the after noon and minimum temp. is at sunrise.As the altitude increase, temp. will decrease in about 6ْC/1000 meter elevation.Temp. in the southern side of the mountain is higher than that in the northern side during day.All these are important factors in selection of adapted spp. Since for each spp. there is minimum, maximum, and optimum temp.) → temp. as cardinal.Van Hoff's law (Q10 law): Every 10ْC rise→2x dry matter production in range of 5 ْC to 35ْC.No. of frost-free days: average period between the last killing frost in spring and the first killing frost in the fall.Heat units: degree-days.
44 Large diurnal range is favorable for net photosynthesis → growth and production. As night temp. increase it affects negatively on production.Vernalization: exposing of seedlings or seeds to low temp periods (according to spp.) , it will induces or increases flowering.Devernalization: reversal of Vernalization, when plant exposed to high temp. (30ْC or more) after low temp.
46 Freezing and chilling injury: If seeds are exposed to Vernalization, moistened seeds under low temp degrees will hinder radicle growth) → 1ْْْC-6ْC from days.Most vegetables are injured at temp slightly below freezing.Freezing and chilling injury:Tropical and subtropical plants killed or damaged at temp. degrees below 10ْC as cucumber, tomato, and potato, especially for long period of time, this is called chilling injury. But if plants subjected to low temp degrees for a short period of time, then increase in temp degrees, the plants will not affect by low temp. before. So time-temp relationship is very important, also the growth stages from an thesis to shortly before flowering is the most sensitive period to cold.Hardening:Exposing plants to cold temp gradually but not suddenly as like cabbage. Also hardening can be done by exposing plants to water stress which can be more applicable.
47 High temp. injury: Dormancy: Increasing the temp. and increasing the percentage of relative humidity affects on leaf temp., it may reach 8 ْC higher than air temp., and if temp rises it results in protoplasm destruction in range of 45 ْC-50ْC. Also ↑ temp. during green fruits stage of tomato → sun-born and scalded of fruit as ripe. Also gradual exposure to raise in temp. with increasing hrs leads to acclimation of exposed plants.]Dormancy:Little or no growth at unfavorable environmental conditions, as decrease or increase in temp degrees, or lack or excess of moisture. Sometimes photoperiod is involved in dormancy all these + seed coat dormancy known as external dormancy, while if seed remain in rest period even with favorable conditions this is called internal or physiological dormancy which related to the changed in inhibitors and/or promoters rate that affected by temp variations. Storage temp. affects also in dormancy were as storage temp increase → duration of dormancy will decrease.
48 B. Moisture or precipitation rate: Tables 6.1 and 6.2 It is affected by geographical characters and it is important as much as temp. in determining the distribution of species.Relative Humidity (RH) = (quantity of water present in air divided on the quantity of water at saturation) multiplied by 100% at same temp. and pressure.
49 Dew point:Temp. of air at which the water vapor reaches saturation point, then as temperature drops down this lead to condensation and formation of dew. Dew + RH% can protect plants from severe transpiration and increase pollens viability but could be a cause of diseases and insect spreading. Amount of rain varies from area to another depending on far or close to equatorial, coasts, mountains, or valleys, also the distribution, If quantity fall in a longer period (up to late spring), there is no need for irrigation, but if all quantity during winter, we need irrigation in summer. Arid regions of less than 250mm/year, semiarid regions of mm/year, sub-humid of regions mm/year, humid regions of mm/year, and in wet regions of more than 1500mm/year as precipitation.Also dew is very important in arid regions, for example, in Palestine drops of dew equal to 25mm/year which is very important in summer, and that can be directly absorbed by leaves and release energy as condensate (540 cal/g of condensate water). But dew increase the infection by diseases as spores of late blight. The plant divided into 3v groups according to water requirement; They are hydrophytes, mesophytes and xerophytes. Water is very important for metabolic processes and its a medium for transport of minerals between cells + transpiration.
50 Table 6.1.: Water requirements of some vegetables a. in.cmVegetables CategoryShallow rooted1230Cabbage1845Lettuce15-2440-60Onion1025SpinachSweet cornMedium rooted12-1830-45BeanBeet1540CarrotCucumberSummer squashPeaPepper
51 Source: Doneen and MacGillvary (1943). Deep rooted1230Artichoke2050Asparagus2460MelonTomato18-2545-60Water melon1845Sweet potatoWinter squashSource: Doneen and MacGillvary (1943).a Water required to raise crop to maturity.
52 Moisture sensitive stages Table 6.2.: critical moisture sensitive stage of some vegetables crops a.Moisture sensitive stagesCropFrom flower bud development through harvestBroccoliFrom head formation to harvestCabbageSufficient soil moisture at all stagesCauliflowerDuring period of root enlargementRadishFrom root enlargement to harvestTurnipAt heading stage to harvest: low soil moisture can cause tip burnLettuceDuring period of bulb formationOnionAt flowering through pod enlargement to harvestPeasFrom tuber initiation through tuber enlargementPotato whiteDuring flowering and pod elongationSnap beansDuring plant growth and floweringSoybeanDuring period of silking and ear developmentSweet corn
53 Source: Some data from Change (1968) a For most vegetable crops little or no moisture stress during entire growth period generally gives high yields and good quality. Flooding is to be avoided.C. Light:Important for photosynthesis, energy, inducing change in plant life cycle as photo period. It varies from mountains (1.75g cal/cm²) to sea levels (1.5g cal/cm²) at noon.Also dust, clouds, smoke, and gases will decrease energy quantity received by earth.At 4.3 Lux (0.4 foot candle) → photosynthesis is negligible, while at 1080 Lux (100 foot candle) it is called the compensation point for many plant spp.
54 Compensation point: light intensity at which photosynthesis rate equal or exactly matches respiration rate, or the point at which photosynthesis and respiration are in balance.Light quality: photosynthesis is highly at lights of wave lengths 480nm (blue) and 680nm (red).Ref.: Tables 6.3 and 6.4 = Response to quality and photo period
55 Duration of light: Photoperiodism: is the flowering response of plants to relative changing length of night or day as the season progresses . Those flower when photoperiod is lower than the critical maximum day length required for flowering, then the plant called short day plant, while those flower when photoperiod is greater than the minimum day length required for flowering, then the plant called long day plant.For short day plant: duration of dark period is the critical condition. Phytochrome is a pigment that absorbs light in red and far-red regions, it is necessary for photoperiodism response.Neutral day plants: not affected by day length.
56 Leaf area index (LAI):Total leaf area (blades) / unit area of land. It is important to evaluate efficiency of photosynthesis, and production of dry matter, it is varying from 2-6, but in some cases it may reach up to 9 or 12, even vertical crops have high LAI. The optimum is not the maximum: since the lower leaves show photosynthesis rate less than the compensation point → it depends on other → so decrease dry matter production. Also optimum is deeply related to solar radiation intensity.
57 Fig.: Relationship of leaf area index and solar radiation of clover. From: Black (1963).
58 Grand rapids (lettuce) 1000-720 Table 6.3: Response to wave length:,RemarksWave length (nm)Responsefar-redStem elongationGrand rapids (lettuce)Inhibition of germination of certain seedsStimulation bulbing of onionredSuppress bulbing in onionTomato fruits-43 LuxRed pigment (lycopene) synthesisStimulate flowering of long day plantsInhibit flowering of short day plantsPromote germination of certain seedsRed cabbage colorPromote red color formation (anthocyanins)PhotosynthesisChlorophyll formationPhototropism
59 Table 6.4: Response to photoperiod: Vegetable nameGrowth responseFlowering response:Spinach, radish, Chinese cabbage,Long-day vegetablesSoybean, chayote, roselle, sweet potato, chrysanthemum, winged bean, amaranthShort-day vegetablesTomatoes, early peas, squashes, beans, peppers, eggplant, most cucurbitsDay-neutral vegetablesGrowth response other than flowering:OnionLong days for bulbingWhite potato, Jerusalem artichoke, yamShort days for tuber initiationCassava, sweet potatoShort days for root enlargement
60 D. Wind:Differences in temp and in pressure creates air motions from high to low pressure areas, its speed depends on differences in pressure. Wind can induce many effects as increasing transportation rate, dust formation, ventilation,decreasing temp, broken and damage of leaves and branches of plants.The use of wind breaks is very important.E. CO2 concentration:That can be affected by wind speed where if high speed then it will keep normal concentration which is important for dens canopy. Also protective structures need CO2 enrichment.
61 2) Soil factors: A. Soil texture B. Soil structure C. Soil pH D. Soil temperatureE. Soil moistureSoil is important for anchorages plants, and its a source of water and nutrient minerals. Soil components are altered by cultivation, fertilizers, irrigation, drainage, and cropping systems. Main components are derived from parent rocks that subsequently interact with climate and soil organisms, leading to formation of soil particles with various ratios and organic matter.
62 A. Soil texture:Is a soil property used to describe the relative proportion of different sizes of mineral particles in a soil. Particles are grouped according to their size into clay, silt, and sand. Soil texture classification is based on the fractions of soil separates present in a soil. The soil texture triangle is a diagram often used to figure out soil textures.Sand particles (2 – 0.02mmӨ), silt particles (0.02 – 0.002mmӨ), and clay particles (<0.002mmӨ). Sandy soils have very low water holding capacity and low nutrient content level. Clay soil (poor aeration): very high water holding capacity and high nutrient content level.Sandy loams: is most easily manageable soil that can provide a well balance of air (aeration) to soil moisture content.
63 B. Soil structure: C. Soil Minerals: Aggregation of soil granules, good aggregation means → adequate exchange of gases (CO2, O2) and water. Compact soil means → bad soil management, little air space and poor water penetration, root fail to develop in a well nature.C. Soil Minerals:Macro: N, P, K, Ca, Mg, S, (C, H, O from CO2 and H2O).Micro: Fe, Cu, Mn, Zn, B, Co, Mo and Cl.Excessive mineral cause → toxicity, while insufficient cause → even poor or abnormal growth.Optimal growth and reproductive process can be realized by proper nutrient balance.
64 D. Soil pH: E. Soil temperature: Most plants grow within a range of 5.8 to 7.5 or little bit more (as it has been classified before). High rainfall means → acidic soil, while low rainfall means → high CO3 content in soil, so it means → alkaline soil.According to PH level some minerals as Fe, Mn become of low availability at alkaline soil conditions, and same will be available at acidic soils in excessive amounts.E. Soil temperature:Depends on air temp, normally it is lower than air temp in spring and summer, and it is higher than air temp in fall and winter. It is important for seed germination, root growth and development of under ground storage organs. (if soil temp is more than 30ْC → poor formation of potato tubers).
65 F. Soil moisture:Water in the soil includes: water vapor, free water (percolated), capillary water (field capacity), hygroscopic, and crystalline (bonded with chemicals). Plant roots can absorb: water vapor, free water, and capillary water. If soil is dry → some hygroscopic can volatilize → water vapor but the amount is too small to be used by plants.As most of capillary water depleted → soil converted from field capacity to permanent wilting point (plant can not extract the remaining water that is at 15 atmosphere).So, states = saturation → percolation of free water → capillary → permanent wilting point. Those are important for plant.Sandy soil: hold very low amount of water, but most available.Clay soil: hold very high amount of water, but 20% - 40% as hygroscopic (on particle size). Saturation for longer period of time, and poor draining which cause root suffocation and wilting even at availability of free water.Growth and photosynthesis rate are largely reduced before plant reaching to P. wilting point.Irrigation systems: furrows, sprinkler, drip systems, misting, and fog.
66 Controlling of growing conditions during off season Tropic and subtropics can be grown all over the year. In temperate climates, summer crops cant be grown from late fall to winter due to cold temp, so off season techniques can enable the production during off season .The techniques are: glass or plastic houses, tunnels, beds, plastic mulches, plastic coverings of the surface.First: Controlling of temperatureSecond: Controlling of lightControlling of temperature: by the following items:Utilizing topographical features: were southern slopes of hilly land receives more radiation quantity during day than level or northern surfaces which means that southern slopes are warmer than northern slopes. So, southern slopes used during cool weather conditions while northern sides used during hot weather conditions. Also slope parts of the hills are warmer than the valley below especially at frost conditions and since cold air remains below.
67 Shape of plant beds: beds of sloping side towards south receive higher quantity of radiation than leveled sides since the rows of plants have east-west direction, and since the angle of light incident to south slope will be almost perpendicular most time of the day.Ref.: Transp. ASoil temp: affected by two factors 1) Soil color: light colored soils are cooler than dark colored soils; 2) Soil texture: coarse soils warm up faster than fine textured soils, also high organic mater soils needs longer time to warm up than mineral soils.Soil moisture: moist soils warm up slower than dry soils since water has higher heating capacity than soil (dry = air). Conversely, moist soils cool-off slower than dry soils as a result of evaporation → cooling of soil and this complicate the relationships. (Summer or warm conditions in relation to winter time).Mulches: if the soil is well-pulverized, which means higher air between soil particles, here air acts as insulated layer, so porous soil conducts less heat than compact soil.
68 Straw mulch, organic matter…, show higher insulating effect in hot days. Soils under those kinds of mulches can be as much as 17ْC lower than those without mulches, and will keep soil warmer than air atmosphere around during cold days, so they need higher heat efficiency up to warm by atmospheric heating system in protective structures.Plastic mulch: clear type warms soil more than black plastic, both prevent losses of moisture, but black mulches has advantages of controlling weeds development by preventing sunlight from reaching the soil surface.Asphalt mulch: as polyethylene type, its effective, clear type warming soils. It is good as anticrusting agent.Aluminum mulch: thin layer of aluminum with biodegradable backing, they are also effective in repelling aphids → control of viral diseases caused by aphids.Ref.: Transp. A
69 Average temperatures 11 AM to 3 PM a Table 7.1: Effect of asphalt and plastic mulches on soil temperature.Average temperatures 11 AM to 3 PM aDepthBlack polyClear polyAsphaltNo mulchedin.cm27.8 (82)31.1 (88)27.2 (81)26.7 (80)28.9 (84)28.3 (82)25.0 (77)2.020.0 (75)24.4 (76)23.3 (74)1½3.820.0 (69)21.1 (70)21.7 (71)19.4 (67)37.515.6 (50)16.1 (61)16.7 (62)15.0 (59)615.013.9 (57)14.4 (58)13.0 (56)1230.0Moisture after 24 days b9.3%7.9%9.9%5.2%0-40-10Source: Takatori et al. (1964).a : Air temperature 23.3ْC (74 ْF); 30 cm (12 in.) width mulch.b : Initial moisture 19.8%.
70 Fig. 7.2: Soil temperature in ْC at 12 mm (½ in.) depth; beds running east-westAm: ante meridiem, Latin for "before noon".Pm: post meridiem, Latin for "after noon".
71 Frost protection:Can be avoided by: fogging and water sprinkling since water has high heat capacity (l cal/g) and as water cools → it releases heat, so application as fogging or mist is important to be continuously as air temp is below freezing point taking in consideration that ice if formed will damage plant parts by its weight, and each gm of water as freezes will release 80 cal of heat preventing sharp drop of temp in the surrounding atmosphere to the plants.Also use of water in irrigated furrows in the night expected to show frost.Heaters and smudge pots: to induce layer of smoke over your crop, its most efficient when the smoke layer is 9-15cm above ground surface, so heating of air between soil and the layer will be common.Fans, wind machines and air crafts: efficient in case of temp inversion in calm areas where air temp is warmer with height, while the air in touch with soil is colder. By machine mixing of air → gaining in soil temp up to 3ْC, if soil temp before mixing is -3 ْC to -6 ْC mixing will not be effective.
72 Plant protective structures: Bushes or paper barriers: in north side to prevent north cold winds and helps in trapping sun heat during the day.Hot cap: a miniature green houses to protect one or more number of plants per structure, made from paper or plastic.Plastic tunnels: that covered with plastic sheets. They are like miniature plastic houses.Cloches: wire frames or wood frames with glass cover. Its strong against wind.Cold frames: made of wood or concrete with plastic or glass covers on the tops which will increase air temp inside the frame. During night it is possible to cover the glass or plastic cover with cloth or straw, this will decrease heat losses since straw is of low heat conduction.Hot beds: as cold frames but heated either by: decomposed manures, flushing of hot air, hot water or steam through pipes or by electric heat cables.
73 7.Lath and screen horses: to decrease light intensity and decrease heat of sunshine, and protecting from insects, (screen) can show higher air temp than the outside since air circulation is reduced.8.Green house, plastic or glass houses: big enough for movement or working, can be heated, cooled, shaded, ventilated and protected from direct sunshine by use of baskets or shade boards that used for seedlings, or shaded ornamental plants, or seedlings at transplanting time.*Hardening of transplants:By exposing them into cooler conditions than in the nursery, but better than permanent field conditions and / or by water stress → to with stand unfavorable conditions. As an example, hardened cabbage can grow without damage up to -6ْC, while non hardened can be injured at -2ْC.
74 Controlling of light:Light intensity: full sunlight intensity is 54,000Lux, compensation point is at 1100 to 3200Lux (no growth but maintaining). So if light intensity is low → artificial light is repaired to reach to normal level needs for most plants to mature (8600 – 11000Lux) light intensity X CO2 concentration X temp.Photoperiod: elongated by light, reduced by dark cloth to induce flowering or delaying it. Longer days → earlier maturity.Application of growth regulators as: PCPA (P-chlorophenoxy acetic acid) NAA (B-naphthalin acetic acid) to set tomato fruits under cool conditions. PCPA + GA → non puffy fruit (firm). Ethephon → hasten ripening.Use of pollinators, vibrators and blowing winds to increase fruit setting.Use of gypsum (hydrated calcium sulfate) in seed beds as a fertilizer to avoid crusting of upper soil and facilitate green color.
75 Fig. interactive effect of light intensity x temperature x CO2 concentration on photosynthesis rate.
76 Growing degree day Growing degree day calculation (GDD) GDD are calculated by taking the average of the daily maximum and minimum temperatures compared to a base temperature, T base !(usually 10 CC) .As an equation:GDD=T max-T min - T base.2GDD`s are typically measured from the winter low. Any temperature below T base is set to T base before calculating the average. Likewise, the maximum temperature is usually capped at 30 cc , because most plants and insects do not grow any faster above that temperature. However, some warm temperate and tropical plants do have significant requirements for days above 30°C to mature fruit or seeds.
77 For example, a day with a high of *For example, a day with a high of.23 °C and a low of 12°C would contribute 7.5 GDDs.GDD`s= _ 10 =7.52A day with a high of 13°C and a low of 10 o~ would contribute 1.5 GDDs.GDD `s= _10 =1.5*So( M.M.Tempreture_ T base)* number of days / month = GDDs/ month
78 *If tomato needs 1500 DDs of maturity and has =10ْ C While temperature of january,febreuary,March, April , May, June ,are: 13 , 15 ,17, 20 ,23 ,25Then when mature if planted at 15 Jan..Jan=16*3 = Feb.=28*5 = Mar = 31*7 =217April=30*10 = May=31*13=403So =392392 = 26 of June15
79 VEGETABLE CLASSIFICATIONS IMPORTANCE OF CLASSIFICATION Some orderly method of grouping different vegetables is essential to catalog or systemize, to some extent, the voluminous information gathered by man since the dawn of agriculture. Such classification can present this material orderly and eliminate repetition of many of the principles related to culture and storage of the harvested crop.Vegetables used throughout the world number in the several hundreds. In the United States alone there are over a hundred, including the minor crops. Therefore, some system of classification is essential.
80 BASIS FOR CLASSIFICATION Methods that can be used for classification depend on its usefulness.Some of the methods or types used:Botanical classification is based according to flower type and structure, and also on genetics and evolution. The groupings of plants are into families, genera, species, and varieties. This classification, based on the botanical relationship, is the most exact system.Optimum growing temperatures, e.g., cool and warm season crops; temperate or tropical crops.Relative resistance of plants to frost or low temperature.Part of plant used for food, e.g., foliage, stem, roots, flowers, or fruits.Number of seasons a plant may live, e.g., annual, biennial, perennial.Storage temperature and storage life.Optimum soil conditions, e.g., soil acidity, and salt tolerance.Water requirements to harvestable stage.
81 TYPES OF CLASSIFICATION OF VEGETABLES Botanical ClassificationAll plants belong to one community (plant kingdom or community).Division:a. Algae and fungi (Thallophyta)b. Mosses and liverworts (Bryophyta)c. Ferns (Pteridophyta)d. Seed plants (Spermatophyta)Classes of seed plants (Spermatophyta):a. Cone-bearing (Gymnosperm)b. Flowering (Angiosperm)Subclass of flowering plants (Angiosperm):a. Monocotyledon (Monocotyledonae)b. Dicotyledon (Dicotyledonae)Order:Family:Genus:Species:Variety (botanical), and Group:Cultivar (horticultural variety):Strain (horticultura1):
82 Example: Botanical classification of the summer squash cultivar, 'gray zucchini' Division: SpermatophytaClass: AngiospermaeSubclass: DicotyledonaeOrder: CucurbitalesFamily: CucurbitaceaeGenus: CucurbitaSpecies: pepo L.1Variety: Melopepo, Alef. 1Cultivar: ZucchiniStrain: GrayDefinitions Used in Vegetable Classification:Group (Botanical Variety-Old Terminology). A population within a species of a cultivated crop which is distinct from the rest of the species forms in one or more1 L. is for C. Linnaeus, the person first suggesting the name; Ale£. for F. G. C. Alefeld.
83 VEGETABLE CLASSIFICATIONS clearly defined characteristics; dwarf growth habit, enlarged taproot, etc. Group designation is used for horticultural convenience and has no botanical recognition.Cultivar: (Horticultural Variety). A cultivar denotes an assemblage of cultivated individuals which are distinguished by any character (morphological, physiological, cytological, chemical, etc.) significant for the purpose of agriculture or horticulture and which retain their distinguishing features when reproduced (either sexually or asexually). When naturally occurring populations are also represented by cultivars, the botanical variety name is retained. The cultivar names are set off in single quotation marks ('zucchini').Strain: A strain includes those plants of a given cultivar which possess the general varietal characteristics but differ in some minor characteristics or qualities. A cultivar with disease resistance incorporated, or early maturation, may be considered a strain within the cultivar. Selections within a cultivar for differences in climatic adaption may be considered a strain. The international code for nomenclature does not recognize the term strain. Any selection that shows sufficient differences from the parent is regarded as a distinct cultivar.Table A.l lists the botanical classifications of many of the more common vegetables of the world.
84 Usefulness of Botanical Classification Strain: A strain includes those plants of a given cultivar which possess the general varietal characteristics but differ in some minor characteristics or qualities. A cultivar with disease resistance incorporated, or early maturation, may be considered a strain within the cultivar. Selections within a cultivar for differences in climatic adaption may be considered a strain. The international code for nomenclature does not recognize the term strain. Any selection that shows sufficient differences from the parent is regarded as a distinct cultivar.Table A.l lists the botanical classifications of many of the more common vegetables of the world.Usefulness of Botanical ClassificationFor biologists to (a) establish relationships and origin, and (b) serve as positive identification, regardless of language.For horticulturists because (a) climatic requirements of a particular family or genus are usually similar, (b) use of crop for economic purposes is similar, and (c) disease and insect controls are quite often similar for related genera.
85 CLASSIFICATION ACCORDING TO SEASON GROWN (after J. H. MacGillivray)2Cool Season Crops-Adapted to mean monthly temperatures of 16°-18°C (60°-65°F). artichoke, asparagus, Brussels sprouts, broccoli, cabbage, carrot, cauliflower, celery, chard, endive, garlic, kale, lettuce, mustard, onion, parsnip, pea, radish, spinach, turnip, white potato.From J.B. MacGillivray Vegetable Production, Used with permission of McGraw-Hill Book Co., New York.2. Warm Season Crops-Adapted to mean monthly temperatures of 18°-30°C (65°-86°F). Intolerant of frost. Cucumber, eggplant, lima beans, muskmelon, okra, pepper, snap bean, squash and pumpkin, sweet corn, sweet potato, tomato, watermelon.This classification is based on temperature zone conditions and even then must be used with some caution. In tropical zones where temperatures are quite uniform, group differences are much less clear.
86 CLASSIFICATION OF VEGETABLES BASED ON USE, BOTANY, OR A COMBINATION OF BOTH1. Potherbs or greens:Spinach, New Zealand spinach, chard, dandelion, kale, mustard, collards, water convolvulus.2. Salad crops:Celery, lettuce, endive, chicory, watercress.3. Cole crops: (all are members of Brassica oleracea except Chinese cabbage)Cabbage, cauliflower, sprouting broccoli, Brussels sprouts, kohlrabi, Chinese cabbage.4. Root crops: (refers to crops which have a fleshy taproot)Beet, carrot, parsnip, salsify, turnip, rutabaga, radish, celeriac.5. Bulb crops: (all species of Allium)Onion, leek, welsh onion, garlic, shallot, chive.
87 6. Pulses:Peas, beans (including dry-seeded or agronomic forms).7. Cucurbits: (all members of the Cucurbitaceae)Cucumber, muskmelon, watermelon, pumpkin, squash, several Oriental crops.8. Solanaceous fruits: (members of the Solanaceae)Tomato, pepper, eggplant, husk tomato9. white (Irish) potato10. sweet potato11. sweet corn
90 5. Fruita. immature:Pea, snap bean, lima bean, broad bean, chayote, summer squash, cucumber, zucca melon, okra, sweet corn, eggplant.b. mature:i. gourd family (cucurbits): pumpkin and winter squash, muskmelon, Chinese wax gourd, watermelon.ii. potato family: tomato, pepper, pepino, husk tomato.
91 CLASSIFICATION OF VEGETABLES ACCORDING TO SALT TOLERANCE3 (RICHARDS, 1954) Listed from high tolerance (top) to low tolerance (bottom)7700 ppm (EC x 103 = 12)1. High salt tolerance:garden beets, kale, asparagus, spinach.6400 ppm (EC x 103= 10)2. Medium salt tolerance:Tomato, broccoli, cabbage, peppers, cauliflower, lettuce, sweet corn, white potato, carrot, onion, peas, squash, cucumber, cantaloupe.2600 ppm (EC x 103=4)3. Low salt tolerance:Radish, green beans.1900 ppm (EC x 103=3)
92 CLASSIFICATION OF VEGET4BLES ACCORDING TO TOLERANCE TO SOIL ACIDITY 1. Slightly tolerant (pH 6.8 to 6.0): asparagus, celery, beet, spinach, broccoli, Chinese cabbage, cabbage, leek, cauliflower, lettuce, muskmelon, New Zealand spinach, okra, onion, spinach.2. Moderately tolerant (pH 6.8 to 5.5): bean, horseradish, Brussels sprouts, kohlrabi, carrot, parsley, cucumber, pea, eggplant, pepper, garlic, pumpkin, radish, squash, tomato, turnip.3. Very tolerant (pH 6.8 to 5.0): chicory, rhubarb, endive, sweet potato, potato, watermelon,3 Salt concentration based on saturation extracts of soils; EC=electrical conductivity.
93 CLASSIFICATION BY ROOT DEPTH INTO SOIL Shallow < 80 cm (3 ft):Cabbage, potato, lettuce, spinach, onion, sweet corn.Medium cm (3-6 ft):Beans, eggplant, beets, summer squash, carrot, peas, cucumber.Deep > 160 cm (6 ft):Artichoke, asparagus, melon, sweet potato, tomato, winter squash and pumpkin.
94 CLASSIFICATION BY HABITAT 1. Hydrophyte (aquatic):Taro, water chestnut, watercress, lotus, water convolvulus.2. Mesophyte:most vegetables grown on soil and requiring moderate amounts of water.3. Xerophyte:cactus, some desert cucurbits (buffalo gourd).
95 Soil and soil preparation: Soil is storage of mineral nutrients and water, it is the home of roots, its chemical and physical properties are very important for production.- Chemical soil properties: can be changed by adding fertilizers, organic matter, leaching, and good aeration.- Physical soil properties: can be changed by drainage, tillage, organic matter, and lime addition.Kinds of soil:Mineral soilOrganic soil (muck or peat)
96 Diameter limits (mm) Name of soil separate No. Based on soil texture which is used to describe the relative proportion of different grain sizes of mineral particles in a soil (relative particle size), so coarseness of soil can be classified into the following groups shown in the table below:Diameter limits(mm)Name of soil separateNo.1.00–2.00Very coarse sand1.0.50–1.00Coarse sand2.0.25–0.50Medium sand3.0.10–0.25Fine sand4.0.05–0.10Very fine sand5.0.002–0.05Silt6.less than 0.002Clay7.
97 According to the table: Water Holding Capacity increase as we go from 1-7.Nutrients level increase as we go from 1-7.Organic matter also increases as we go from 1-7.Soil preparation is more difficult from 1-7.
98 Mineral soils:They are separated into three groups: sand, silt, and clay. Those mineral soil classes preferred by vegetables are: sandy, sandy loams, silty loams, clay loams, in addition to muck or peat soil as organic matter soil.The preferred soil by vegetables could be determined by:Species growth: its root system; is it legumes or normalEarliness: sandy soils are the most of them ready to be plowed after rainfall.Growing structures.Water availability: irrigated or rain irrigated.Length of growing season of crop: sandy soils are not good for long growing season crops, while heavy soils are better
99 Silty loam or loamy soil: in which crops can continue there growing season in hot summer, its also increases production.Muck soils: that contains less than 50% of its components as organic matter, while peat soils contain more than 50% of its components as organic matter.Both muck and peat soils composed of plant materials in various stages of decomposition, and they are characterized by:1) High organic matter level.2) Brown–black color (according to the degree of decomposition).3) High water holding capacity: which may reach up to several times than it's weight, but the unavailable water is also increase.4) High N content (about 1.5% – 2.5% of dry weight).5) Low content of other minerals especially K.Muck soils are excellent for celery, lettuce, onion, carrots, beet, spinach, and cabbage; that can with stand frost conditions and they are relatively of short growing season which could be determined mainly by frost dominance.Also muck soil is of poor conduction to heat because of low heat movement from lower surface to upper surface (inverse to clay loam).
100 Frostiness depends on: Moisture content: it makes heat movement upward more easily.Compactness: and its effect on heat movement.Start of decomposition: presence of higher amount of minerals will decrease the probability of frost conditions.Mineral content especially as fertilizers: it affects against frost.Decomposed matter from deciduous and shrub trees is better than those from confers since confers decompose slowly because of the presence of resins.Drainage and tillage (make good soil aeration), which is favored for growth of many organisms, which means better decomposition. Also addition of lime can improve the media for good organisms growth (low acidity).Availability of water in medium soil is higher because of medium particles size.
101 Soil preparation methods: DrainagePlowingDiskingHarrowingRollingGood prepared soil means = smooth soil, free of clods and fine soil surface, so you can plant even a small seed in a uniform depth, which means uniformity in germination → high uniform stand.1) Drainage:Is the natural or artificial removal of surface and sub-surface water from an area, many agricultural soils need drainage to improve production or to manage water supplies.
102 Its important for:Early preparation of soil (better sandy soil), to reach field capacity faster.Better soil aeration that is important to plant growth (better root respiration), and for microorganisms.Improve nutrient availability to plant.Allows soil to warm earlier in spring.The efficiency of Drainage:1) Rain full intensity;2) Soil type;3) Permeability of underlying material layers.(50ft-0.5mile is the distance between tile or open ditch).Drainage is more important in muck soils than in mineral type soils to increase the activity of microorganisms which required for decomposition.
103 It is done by:a) Ditches: in the first few years of cultivation.b) Tiles: better because no obstacles to cultivation practices, save land of ditches, save labors of cleaning ditches and weed cutting.Normally they are established at depth of 3-5 ft. (rain fall intensity, and soil type, are protected from being destroyed by machines, tiles port to canals or ditches.
104 2) Plowing:Is a tool used in farming for initial cultivation of soil in preparation for planting.The primary purpose of plowing is to turn over the upper layer of the soil, bringing fresh nutrients to the surface, while burying weeds and the remains of previous crops, allowing them to break down, and it allows better root penetration. It also aerates the soil, and allows it to hold moisture better.Plowing depth:inches, is sufficient in most soils.Deeper plowing depths means poor surface soil.Plowing time depends on:1) Time to plant crop;2) soil type3) environmental conditions (rain fall and temp).
105 *Some advises: Shorten time before the planting date. Longer time as possible if there is soil improving crop (high vegetative growth of this crop), which needs maximum organic matter enrichment.If there is no irrigation, its perfect for plowing completely the soil.Don’t plow when too wet (causes the formation of clods), or when too dry (it will destroy soil structure), proper time is when its at field capacity.After certain irrigation or rain fall times, plowing can eliminate weeds.Don’t use heavy machines, deep plowing done gradually to avoid formation of plow panes.
106 Main advantages of plowing: Kill weedsCreate fine seed bedMix plant residuesReduce erosion by plowing against slope and collecting water in unbroken furrowsImproving physical and chemical status by good aerationIncrease the rate of organic matter decomposition when turned under
107 3) Disking: 4) Harrowing: It refers to the farm implement used, so a "disk" is a type of plow that uses a round toothed blade to cut the surface of the soil, it does not break the soil up as deep as other types of plows and leaves a quantity of plant litter on the surface of the field.4) Harrowing:Soil broken up, the purpose is generally to to break up clods and lumps of soil and to provide a finer finish, a good tilth or soil structure that is suitable for seeding and planting operations. Such coarser harrowing may also be used to remove weeds and to cover seed after sowing. Tools for harrowing are commonly called harrows.Disking and harrowing done soon after plowing, has the object to level, smooth either the surface by spike tooth or to pulverize clods and sod parts turned under by spring tooth harrow that bring them up, then with harrow smooth surface.
109 5) Rolling:Heavy clay soils drains slowly, meaning it stays saturated longer after rain or irrigation. Then, when the sun finally comes out and the soil dries, it forms a hard, cracked surface, so the remaining clods and sod after all preparation methods above, could be crushed by rolling, rotivation, dragging: that means smooth soil surface, which increases the efficiency of fumigation.
110 Manures and soil improving crops: Manure: is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of the soil by adding organic matter and nutrients, such as nitrogen that is trapped by bacteria in the soil.Intensive cropping system: to plant two crops per year.Depletion of the organic matter in higher manner than what plant residues turned back.Added organic matter could be decomposed by microorganisms → CO2.Microorganisms evolve 1gm of good soil organic matter (about 2,000,000 microorganism).Soil of low organic matter decomposition contains about 100,000 microorganism.Rate of organic matter decomposition depends on: 1) Moisture of soil (not too much wet or too much dry); 2) soil type; 3) temp linear relation ship to certain limits; 4) crop type: as cabbage which causes loss of soil organic matter more than in case of sweet corn.
111 Improves soil structure. Advantages of organic matter addition:Increasing carbon exchange capacity by increasing nutrient content and colloidal function.Increasing water holding capacity especially in sandy and light soil, and increasing drainage in clayey soils.Improves soil structure.Increasing soil aggregation by cementing soil particles which will increase soil permeability to water, and soil aeration.Increasing the nutrient status of soil.Organic matter releases CO2 by decomposition.Organic manures provide food for soil organisms like earthworms which are responsible for improving soil quality.Crop rotation is not practiced in vegetable cropping, so the choices are addition of organic matter or using soil improving crops.Decreasing soil erosion and leaching by wind.
112 Fresh manure has disadvantage: Manures: important to increase organic matter content than nutrient enrichment in the soil because the last could be realized by chemicals.Fresh manure has disadvantage:At the beginning of it's addition, microorganisms in it compete with plants on minerals especially nitrate (appears as yellow symptoms on the plant), but later on when these microorganisms died (decomposed), it will be a good source of nitrogen for plant.So it's better to add fermented manure or to do fermenting before planting.N manure is slowly available, about 5% annually (decreasing percentage), there is a problem of leached NO3.Good for long season crops and successive cycles.Manure has greater efficiency in case of sandy soils, but at the linear stage of vegetables growth there should be some addition of chemicals to substitute manure shortage → intensive cultivation.Also microorganisms release gibbrellin which has a positive effect on growth of plant → but it may cause lodging.
113 Advantages and disadvantages of applying non decomposed manure: Burning effect on plant by rapid decomposition of urine especially in open porous soil and increase of ammoniaLow loss of important ions by leaching + gradual decomposition1.Suffering at early stage by microorganisms competition on NO3Desirable organisms are found in fermented manure2.Interfere with water movement after being plowed underNon decomposed part improve heavy soil and affects on aggregation3.Presence of viable weed seeds and microspores of disease, which is better to be partially decomposedChange of some insoluble compounds to soluble through contact with decomposed manure (as a function of heat)4.Weed and pathogen killing5.
114 Advantages of applying full decomposed manure: Have more available mineral elements and in high concentration.High balanced combination of NPK since k can be obtained from stalk of weeds and vegetables.No burning effect.Major part of weed seeds presented in manure but not in soil, are killed by decomposition.Not interfere with soil preparation since decomposed out.There is no N starvation due to microorganisms competition.Time to apply; depends on:Kind of manure: that from cows applied in advance of planting, it takes time to be decomposed.Stage of decomposition.Kind of crop (long season → needs amount to be added earlier, while in short season crop it will be decomposed) advised on crops of high profit.Rotation system of manure: it's good to apply manure to vegetable crops or to crops preceding vegetables.
115 Soil improving crops: Rate and method of application: depends on: 1) Economic situations2) Kind of crop3) Fertility of soil4) Manure typeFrom Ton / Acre is good supplemented by chemicals.Hen manure added with lower rate than others because of high N content.Methods of application: Broad cast if abundant, or in beds or mixed in furrows if in limited amounts.Soil improving crops:Used to improve organic matter conditions of soil so as to be good for succeeding crops.
116 They are divided into:Green manure crops: just planted with soil improvement scope and turned under while green, cultivated in the same season of crop in rotation.Cover crops: to improve and protect the soil from both wind and water erosion, grown in winter time so not to interfere with growth period of vegetable crop.Root distribution in soil profile gives better enrichment and distribution of organic matter, and better improvement of soil structure because it decreases leaching by increasing absorption to that will be used by soil when turned under.Legumes improve N status of soil.
117 Selection of soil improving crop depends on: Adaptation of crop to climatic conditions and soil characters.Quantity of vegetative matter released (export).Root characters of improving crop.How much easy to incorporate organic matter often in soil.Time in the year to be planted (soil improving crop)Easy to eradicate the improving crop (remained).
118 Soil improving crops requires cultivation techniques as normal crops. Intensive vegetables cultivation requires high quantity of organic matter so two soil improving crops could be mixed (in the presence of coincidence growth between them).As: Rye (in any soil, resist cold) alone or with Sudan grass, sunflower, rape, and mustard.Also legumes could be used (as a source of organic matter, and conserves Nut, and increases N content).In summer: clover mixed with alfalfa, cowpea also is good.
119 Time to turn under the soil improving crop, depends on: Time to plant succeeding crop: if early crop, turned in early spring, but if late crop, prolonged period to increase organic matter.Kind of soil improving crop.Growth season of improving crop.Soil characteristics.Climatic condition during growth of soil improving crop.
120 It is desirable to apply N ( pounds/acre) as Ca–N compound, Ammonium nitrate, and urea, at turning under time in order to titrate the C/N towards N so as to increase food and also energy for microorganisms, which is important in the decomposition of plant material and when microorganisms die → N consumed will be available for vegetable crops.In case of shortage of water: it's better to decrease the period of soil improving crops to: keep certain level of moisture for next crop (vegetable crop), and for rapid decomposition of plant material from succulent tissues of soil improving crops than dry material if remain until maturity which also will be enhanced by temp and water content of soil.
121 Commercial Fertilizers The term used for all material (other than animal manure) applied to soil to furnish new materials to plant.Maybe single chemical or compound as (potassium nitrate or could be a mixture of N P K) or organic materials as bones, cotton seeds …They are very important for plant vegetable crop because of:Their high availability to face high demand of vegetable especially at linear growth stage and intensive cultivate.Provide well balance of different elements.Cheaper, easier, faster to resolve deficiency problem than manure (especially with presence of irrigation system).
122 Elements required by plant can be subdivided into: Macro elements: that needed in large quantities for plant growth and development. It includes: C, H, O (all supplied by the environment), N, P, K, Ca, Mg, and S.Micro elements: essential to plant as those macro but needed in small quantities. It includes: Fe, B, Mn, Cu, Zn, Mo, Cl, Co, Na, Si, and V (vanadium).It is important to fertilize the soil with adequate amounts taking in consideration the following points:Slow availability of these elements because of slow change from complex forms and the mobility of elements, simple forms could be leached.Shallow root systems.Purity of chemicals: this required diversification in chemicals to apply and use systems that enable high frequency.Intensive cultivation that needs more fertilizers with which symptoms of deficiency appear clearly but it should be taken in consideration the pollution it may cause to water, soil, and the accumulation in fruits.
123 So commercial fertilizers: formed from one or more of those elements needed for plant development Commercial fertilizers include:Complete fertilizer: contains N, P, K and some oligo elements. For example a commercial fertilizer contains N P K in the ratio of 10:5:10: this means that in each 100kg there is 10kg of pure N, while for P and K they could be expressed as P2O5 and K2O.Also fertilizer formula is important; it detects the source of each element, as for example N from urea, P from phosphoric acid, and K from potassium oxide. Why to know the formula? it helps in determining the solubility of fertilizers because soluble fertilizers should not be added in pre planting stage as they dissolved and lose by leaching or with drainage, or evaporated as gas as there efficiency decreased because of environmental conditions.What do fertilizer ratio means? the ratio as 2:1:2 of N:P:K helps to determine what fertilizer ratio to buy, which serve more for every certain crop and even for each stage of growth.
124 B. Fertilizers of one element as those of N, P. C. Fertilizers of two elements or more as ammonium sulphate potassium sulphate.D. Foliage fertilizers: contains minor elements, they are sprayed on leaves to be more efficient to correct the deficiency symptoms since they are absorbed by faster by leaves.Foliages are important to avoid mixing of elements that leads to precipitation of some other elements (this decreases the availability of some elements), as Fe with Ca or P → precipitate Fe.Also could be applied with certain pesticides → decreases cost.
125 Fertilizer management related to: 1) Crop characteristics:Depth of root: shallow roots needs surface and frequent application, while for deep roots apply fertilizers in furrow or by drilling machines.Growth rate: linear stage requires more than othere stages.Type of crop: foliage crops needs high N ratio, while fruity veg. crops are normal.2) Soil characteristics:pH: alkaline soil solution decreases availability of certain elements as fixing of P as triphosphate (complex), but its not absorbed by roots, also Fe, Mn, and B, (but Fe and Mn highly available with acidic conditions and may become in toxic levels.Acidic soil may influence to certain level the assimilation of Ca, Mg, Mo which preferred sub alkaline soil.In general macro elements are highly disponible for plant within neutral pH range.
126 Soil fertility status determined by: History of fields records. Salinity: amount of salts dissolved in soil solution, which affects the osmotic potential and cause toxicity, plasmolysis and death of plant.If salinity is high = fertilization in ration manner with more frequents and ready irrigation system to wash.Moisture level: with moistured soil → plant will be more efficient in utilizing fertilizers, but after certain level availability will be decreased as a result of high leached amount. (NO3 -, NO2 -, Ca ++, Na +, Mg ++).Soil fertility status determined by:History of fields records.Symptoms on plant.Soil test.Plant analysis.Rhythm at absorption.
127 IrrigationIrrigation (water intake) is an artificial application of water to the soil. It is usually used to assist in growing crops in dry areas and during periods of inadequate rainfall. Additionally, irrigation also has a few other uses in crop production, which include protecting plants against frost, suppressing weed growing in grain fields, and helping in preventing soil consolidation.In contrast, agriculture that relies only on direct rainfall is referred to as rain-fed farming.Irrigation is often studied together with drainage, which is the natural or artificial removal of surface and sub-surface water from a given area.a. Infiltration: down ward flow of water through soil small pores.b. Percolation: down ward flow of water into soil through large pores and through cracksc. Capillary: up ward flow or out of soil.
128 Factors affecting water intake: A- Some factors increase it, as:Soil cracking: resulted from dryness of heavy soil (clay) → and this will increase water flow, it can be avoided or decreased by; continue movement; and spreading manure at the surface.Tillage: more efficient in medium to heavy soil.Organic matter: adding it to soil improves soil texture especially light soils (it will aggregate and this will increase its water holding capacity), but if heavy soil it will improve its pore space and so water penetrates more.Crop rotation: it increase the organic matter content in the soil since crops used one after one → decay of their remaining roots and increase organic matter content → and increases pores as in (3) → because of aggregation.Topography: level soil will increase the chance of flowing water down ward and this will increase water intake.
129 B- Some factors decrease it, as: Surface sealing: formation of thin compact layer on soil surface which prevent or decrease water intake.Soil compaction: formation of compacted layers in cases of:Plow pan: resulted from plowing the soil to the same depth year after year and below this depth no water intake, so plow pan reduces water infiltration and percolation.Hard pan: resulted from moving heavy equipment over the soil as lories and tractors, they creates on lower depth hard pan or could be formed from very heavy clay layers if found, so it decreases water intake.Salts in soil: especially Na-salts or Mg-salts, which causes soil sealing which appears as oil spots where water react and combine with Na or Mg-salts causing sealing or blocking of water movement as layer.Sediment in irrigated water: if you irrigate with water that has high percentage of silt, then after time and by the accumulation of silt the water penetration and intake will be reduced as pores percentage will be decreased.Topography: adding water on soil with slope → this will increase the run off and water intake will be reduced; it can be improved by making terraces and grading of soil.
130 When to irrigate: Wilting: includes: A) Plant signs that appear on plant, they are:Wilting: includes:Midday wilting: at midday where transpiration is very high and greater than absorption rate → lose of water from plants tissues is high, which leads to wilting, but afternoon plant will recover and targor pressure of cells returns full. (Plant function is related to targor pressure).Temporary wilting point: if the plant shows wilting at the early morning → you should irrigate directly because the plant need more time to recover and return normal.P wilting point: most sever type that may cause damage of plant with which plant will not recover.- So irrigation should be done before this stage and not later than temporary wilting point stage, normally at 50% of field capacity.
131 2.Color of plastids: light green color means normal plant, but black green means the plant needs irrigation.3.Temp.: you come at the midday, just feel the leaves if they are cool, it means the plant doesn't need irrigation, but if the plant is hot, so it needs irrigation.4.Growth rate: plants of well supply of water show steady growth rate and noticed development, while at water stress → growth rate will be slow or not noticed. This point is very efficient in linear growth stage of vegetable crops.5.Stage of development: for each spp. there is critical point in it's life cycle at which if the spp. exposed to stress will decrease their yield as: potato and melon: critical period is from blossom to harvest
132 Sweet corn: from tussling – silking (male formation flower-appearance of style on female flowers). Onion: during bulb formation and development where 50% or more of the bulb growth is in the last days.Lettuce: just during heading where 50% of it's growth done in 50 days, while other 50% are accomplished in one week, so it is critical time (this week) to irrigate in frequent manner.Cauliflower: at the time of curd formation. تكون الحامل الزهريCabbage: during heading, and as head starts to develop.Tomato: has deep root system, so it needs water from transplanting till to be established in the soil in frequent way, then with wider interval so as to encourage root penetration not to remain on the soil surface. At fruit set → abundant irrigation is required.Cucumber: shallow rooted crop (60% of root found in upper 30 cm), so it can't tolerate water stress at any time especially at the beginning (establishment) and during fruit set.
133 B) Soil signs:The availability of moisture in the soil, its measured by:You can determine it by Auger , take a sample, then feel the sample by hand:If soil is course (light soil) when catched: stick together but not forming one ball, it means that it needs irrigation.If soil is medium: when catched, particles crumble from each other, it means that it needs irrigation.If soil is of fine texture: when catched, particles forming a ball together but will not form a ribbon, it should be irrigated.2. Soil moisture tension: measured by Tensiometer, where irrigation based on soil moisture tension.
134 So we can summarize the factors that indicate the amount of irrigation water as follows: More irrigation rateLess irrigation rateFactorHotCool1) WeatherDryHumidWindyStillShallow rooted systemDeep rooted2) PlantDamaged root systemHealthy rootsComplete crop coverageIn complete crop coverageSuperficial soilDeep soil3) SoilCourse textured soilFine textureHigh salt contentLow salt content
135 Types of irrigationFlood irrigation: either uncontrolled or controlled flood, this method used for leaching of excess salts, soil needs before starting the flood a kind of flattened and start from the upper point of the field.Disadvantages:Can cause soil erosion especially sloping areas at high flow rate.Consumes large amount of water because by this type every inch² of soil is flooded with water.furrow
136 2. Furrow irrigation: is one of the surface irrigation methods which classified by the slope, the size and shape of the field, the end conditions, and how water flows into and over the field. Furrows provide the irrigator more opportunity to manage irrigations toward higher efficiencies as field conditions change for each irrigation throughout a season. Furrow irrigation avoids flooding the entire field surface by channelling the flow along the primary direction of the field using 'furrows,' or 'corrugations'. Water infiltrates through the wetted perimeter and spreads vertically and horizontally to refill the soil reservoirCan be straight furrows.Can be zigzag furrows.Not costed but consumes a lot of water.
137 3. Sprinkler irrigation: called head irrigation because water is ported to head then by pressure will also be pumped as natural rainfall. No need to level the land, the design of this system should based on the equation (water discharged = water intake). If water discharged > water intake → leads to erosion, this method is more efficient in increasing seed germination than furrow and better to overcome frost problem.Drip systemSprinkler system
138 4. Drip irrigation: (save labor cost as well as sprinkler), water is applied just to the plant, it is highly efficient system and face the evapotranspiration requirement and control incidence of weeds diffusion than sprinkler, and control the amount of water (important at areas of limited water sources as Jordan).Disadvantages:Superficial accumulation of salts that needs soil washing from one season to another.High cost since it requires pumps, pool, main line, sub main, drip lines, drippers, filters. Dripper could be: normal as key clipp, eye clip…Biwall: small pores make in both or one side of tube.Via flow: perforated tube where water pass through as if through natural pores of cloth.
139 5. Basin method.Schedule shows some irrigation equipments:
141 Onion Origin: Alliaceae (Amaryllidaceae, Liliaceae) Family: Allium Genus:cepaSpeciesOrigin:Cultivated for over 5000 years, the onion is one of the oldest and most used vegetables in the world. Originated in Iran and West Pakistan. Cultivated by the Egyptians, Greeks and Romans. Brought to North America by the Spaniards.Long considered of medicinal value.
142 Botany:The onion is a vegetable composed of successive concentric layers of leaves. These fleshy and juicy layers of skin are wrapped in a last layer of paper-thin peel that changes colour when the onion is dried. There are many different varieties of onions with colours ranging from white to brown, to red, to purple. Onion is herbaceous crop, biennial if produced from seeds, but it can be grown annually if propagated leafy or by bulbs production. It has shallow root system up to 30cm deep in the soil, having a number of adventitious roots (1.5mm) from disc stem, that continue to develop during early growth then with maturity of bulb → roots will die.Leaf is produced from apical meristem pushing the older leaf sheath bases to the out side having hollow blade. Bulb resulted from swelling of leaf bases while inflorescence appears after vernalization in the 2nd year forming an umbel shape on terminal point of scape including flowers. Cross pollination by insects, seed of low viable duration at room temp (2-4 years), but at low temp and low RH conditions we can increase the viable period for several years .
144 Culture: Fertilizers: Moisture: Climatic requirements: onion is a cool season crop ºC, tolerant to frost, low temp is needed during early stages of growth before bulbing to avoid halting, good bulbing germination at 25ºC and growth rate start to decrease at temp degrees higher than 27ºC. Vernalization is important for flowering. Photoperiod is important for bulbing, but now new cultivars of various photoperiod requirements are presented.Fertilizers:, , of N, P, K respectively are needed, avoiding Ammonium ions NH4+ application close to plants since Ammonia NH3 can induce toxicity to plants .Moisture:Since it has shallow fibrous adventitious root system → roots concentrated in upper 30-50cm, so mm of water is required according to location to ensure development, establishing of new formed roots. So addition is in frequent manner especially at critical stages.
145 Propagation: Transplants: Bulb lets (onion sets): Propagated by seeds (sexual) or by bulb lets, then planted either seedlings or bulb lets in beds with 35-45cm between rows x → reaching to about kg/ha as seeding rate for bulb production while for green bunching → seeding rate X6 of the previous. In general, wide rows work very well for onions.Bulb lets (onion sets):Produced in fall 1-3cm, and then planted in late winter-early spring of the following year → to give green or mature onion. Sets are produced by seeding in good seed bed of light loam soil, g/m² (2-4cm²/seed) X 6-12mm depth. If planting density increased then bulb lets size will be smaller.Transplants:If you have 10cm x 35cm → 275,000 transplant that has 3-4 leaves after 8-12 weeks in nursery and less than 6-7mm in diameter at plant base, so as to over winter conditions of less than 15ºC at transplanting time.
146 Bulbing:An important aspect of onion development is the length of day (photoperiod). Photoperiod, along with temperature, controls when the onions form bulbs. Long-day onion varieties will quit forming tops and begin to form bulbs when the day length reaches hrs, while short-day onions will start making bulbs much earlier in the year when there are only hrs of daylight. Intermediate onions requires from hrs, and very long day onions requires more than 16 hrs → for induction of bulbing not for floweringShort day onions: that initiate bulbing at shorter day, than others that means = bulbing occurs when the photoperiod is longer than the minimum period for CV to do bulbing which incase of short day hrs.Also temp can affect bulbing: high temp speeds up the bulbing process to certain limit where at 40ºC of tropics → retards the bulbing. Interaction of photoperiod with temp: short day x high temp → No bulbing but continue to form leaves.
147 Short day onions: that initiate bulbing at shorter day, than others that means = bulbing occurs when the photoperiod is longer than the minimum period for CV to do bulbing which incase of short day hrs.Also temp can affect bulbing: high temp speeds up the bulbing process to certain limit where at 40ºC of tropics → retards the bulbing. Interaction of photoperiod with temp: short day x high temp → No bulbing but continue to form leaves.Also: Ethephon (2-Cl-ethylphosphoric acid) spraying on leaves at 1.2g/L induces bulbing of any onion class and enlargement of bulbs at short day, can be realized by repeated sprayings.
148 Harvest:Bulb onions grown from transplants (seedlings) or sets will need about 3 months to reach maturity. Many onions are ready to pull up and harvest by late summer, roughly late July or early August. It will be necessary to gather onions from the soil by hand, they are harvested with leaves and then leaves are cut.When their tops have fallen over, onions are fully mature, they are ready for harvesting. Onions harvests after falling down of leaves (water stress) then stored in conditions around 0ºC (not much lower).Curing: to prevent entering of rot organisms through the tops (cut) by allowing drying in files or to be exposed for current wind for days. If piles → better to be protected from direct sun to avoid scalding allowing in the same time air circulation. Also forcing heated air at 46ºC-47ºC can be pumped through piles for hrs
149 Storage:The most important factors for proper onion storage are good air circulation, relative dryness and cool temperatures with low humidity. In order to properly store onions, they must be well ripened and cured. Those that are immature, soft, or “thick necked” should never be placed in storage but used as soon as possible since they are still Juvenile (less bulb diameter). So, as bulb diameter increased, it becomes more sensitive to cold storage conditions.Storage: at 0ºC-7ºC or at 25ºC-35ºC → no sprouting in both cases up to 6 months, while at 15ºC-21ºC poor storing condition even at 40% RH or less and 3ºC → 1 year storage period.
150 Sprout prevention in storage: Rest and Dormancy:That occurred directly after maturity of bulbs which varies from CV to other in period where bulbs will not sprout even under optimal condition of temp and moisture this rest after certain period start to disappear gradually. Also during dormancy if bulbs expose to suboptimal → No sprouting then when removed → Root emerges before leaves if you remove roots → delay.Sprout prevention in storage:By using Maleic Hydrazide (MH – 30) that sprayed on crop before harvest when tops are still green or at least the plant should have = phs active leaves using 2.2 to 3.4 kg/ha. Also Y radiation can inhibit sprouting.Nutritive value: high in energy, of medium nutritive value among vegetables containing CHO as sucrose glucose, fructose, green onion tops have high provide a content.
151 Pest and diseases: Red spider mite at dry climates → will be serious. Trips: as sucking insects from onion tops.Leaf miner that feeding under epidermis → ↓ yield.Cut worms: that can cut off young plants from base.Nematodes and wire worms as soil born pest that attach the roots.Onion maggots (يرقة) that infest sets and bulbs.Downy mildew: very serious at humid climates.Neck rot by Botrytis ellii attacks bulbs or stalk of onion grown for producing seeds.Soft rot: by Bacteria → water socked areas → soft watery tissues.Leaf molds, Black mold, fusarium hasel rot, smut.Viral disease that causes chlorotic → hollow streaking, stunt and distorted flattening of leaves, mainly by aphids.
152 Potato Family:Solanaceae Genus:Solanum Species:tuberosum Solanum tuberosum originated in high lands of Andes (Peru, Columbia, Ecuador, Bolivia) of South America.Origin and History:In 1537 it was introduced to Europe by Spanish Explorers. In less than 100 years it became a staple crop.A plant disease known as late blight, spread rapidly through the poorer communities of western Ireland, resulting in the crop failures that led to the Great Irish Famine, where millions died of starvation and other millions migrated to U.S.A, because they are mainly depending on potato
153 Botany:A stem tuber forms from thickened rhizomes or stolons. Potatos are stem tubers, which are the development of enlarged stolons thickened into a storage organ. Potato is annual crop which means that the tuber is produced in one growing season and used to perennialize the plant and as a means of propagation. Also, its herbaceous, dicotyledonous crop that reproduced asexually. CM2 No. is 48 of the commercial potato (2n = 48) → Tetraploid since the diploid is (2n = 24 as in wild potato).Transp. 2Stolon: a slender horizontal stem of a plant that grows near the surface of the ground; it can sprouts buds that can become new plants; potato tubers grow at the end of stolons.Is not true one but it is Rhizomes.
154 Potato Culture:It is a cool season crop; optimal temp for increasing yield is 16-18˚C. Freezing damage crop and above 20˚C tuberization will be decreased up to 29˚C, where tuberization inhibited.For every 1˚F above optimum temp → yield will be decreased by 4%.Optimum soil temp is 22˚C, lower or higher temp → retards the emergence of sprouts, which varies from cultivar to other.High soil temp seems to increase knobbiness (>29˚c), poor shape and many tubers in the same stolon
155 Tuber initiation: Affected by: Photoperiod: short days will induce tuberization.Temp: if days are long so night temp should be less than 20˚C where optimal night temp is 12˚C for tuberization and the sensitive part for tuberization is tops but with no stolon.Low nitrogen level → shift to tuber.High light intensity → enhance tuberization.So, as potato planted in early spring (tops establishing), and as weather warm and days are longer → storage begins in tubers.
158 Growing season of potatoes should be frost free days, where as growing season decrease in northern latitudes, long days compensate this condition to enhance tuberization, (20˚C x 85 RH% for about 4 days), and using presprouted tubers shortens the growing period about 10 days besides removal of apical bud after emergence.
159 Soil, Water, and Fertilizers Sandy loam, loam, Silt loam or peat soils give high quality potatos.So loose textured, well drained soil of pH of is the best soil since high soil moisture leads to formation of large lenticels and heavy soils give no tubers.Also soil should be of cm depth since roots can reach below this depth.A total of mm of water is required during the growing season.N, P, K: kg, kg, and kg/ha. respectively according to fertility level of soil which should be distributed intervals (N) avoiding leaching and excess of N → delay or no tuberization.
160 Spacing:Seed tubers that having g/tuber are placed at 5-10 cm depth x cm x cm between rows. If seed tuber are big, then cut into pieces having at least one eye (bud) allowing heading (suberization) of cuts by keeping them at 18-21˚C, 85-90% RH for 2-3 days after being treated.Normally 2.5 million tons of tubers are needed/ha.Production of certified tubers:Start with producing virus-free tubers by tissue culture then testing eye for bacterial ring rot → Elite I select → Elite II selection, Elite III → fonnlation tubers → certified that used for → commercial side process.Producing commercial cultivars:By growing the certified tubers in cool region where infected plants show symptoms on their tops → rouged of plants and tubers.
161 Harvesting and storage: Yellowing of vines means maturity of tubers.If you want to harvest earlier → vines should be beaten down few days before harvest → skin formation on tubers.Careful handling to minimize bruising and formation of black spot.Under mulch there is no green color.Curing:For 4-5 days at 16-21ºC and high RH to heal and suberize cuts which normally done by storing foundations.Storage:Best storage conditions are at 4-10 ºC x 90% RH in dark well ventilated space to avoid sprout development, disease infection, moisture loss by low temp, and avoid chlorophyll green color development and solanin (toxin), (for better taste formation) → death but low temp. Starch converts to sugar → ↓↓ storage durability which can be overcome by storing them one week before consumption in 18-21ºC → then sugar converts into → starch.
162 Sprout inhibitors:By spraying plants 2-3 week before harvest with maleichydrazide at ppm or by 0.5% solution of chloro IPC (isopropyl-N-tetrachlorocarbamate) and nonyl, or by Arayl alcohol ( mg/L) in atmosphere of storage rooms.These treatments will be effective after the rest period (internal dormancy) which lasts from 4-15 weeks.Nutritive value:Rich in CHO (energy components)Rich in minerals and vitamins, (good in vitamin C content).Low in proteins and proti amin A (Isoprene units).Pests and diseases:Colorado potato beetle, aphids, leafhopper, wire worm, tuber worm, spider mites and thrips, early blight, late blight, bacterial ring root, rhyzoctonia, verticillium, fuzarium and 10 viruses caused by aphids and insects.
163 Sweet corn Family:Gramineae Genus:Zea Species:mays (Transp. 3) Its classified into the following sub-species:Sweet corn sacchorata: the sweetish endosperm and starch accumulation increase with maturity.Pod corn tunicata: enclosed of kernel in a pod as well as the ear enclosed in a pod or husk.Flour or soft corn amylacea: soft or flour endosperm.Hard corn or flint corn indurata: field corn that has starchy endosperm, large kernels of round tops, they are called roasting ears when harvested at immature stage which used as vegetables.
164 5)Dent corn indentata: of corneous, soft, and white starch endosperm producing a dent character at mature stage.6)Pop corn everta: small kernels and small ears with major portion of endosperm.7)Waxy corn ceratina: that is entirely formed of amylopection while other subspecies are formed of amylose and amylopection.Amylopection: is a starchy aqueous solution that set to shift gel at room temp.Amylase: is a starchy aqueous solution that not gel at room temp.
166 Origin:There are several theories about the specific origin but it says that sweet corn originated in South America, Mexico and Central America.Botany:Annual herbaceous monocotylodonous plants bearing by seeds (sexual) → it is monoecious plants with separate male and female flowers, bearing the tassel as terminal inflorescence and ears as lateral inflorescence at the axis of leaves. Shallow rooted crop. Warm season, frost-sensitive crop. Harvested organ: immature fruit (typically harvested 18 to 21 days after pollinating).
168 Culture:Warm season crop, that needs frost-free days, having 21-27ºC optimum soil temp for germination and not less than 13ºC, the optimum temp for growth is 21ºC-30ºC showing at range of 16-35ºC.Flowering:Influenced by:Photoperiod: short photoperiod promotes flowering, while long photoperiod takes longer time for flowering. So tropical cultivars don’t flower in temperate regions until day length decrease to hr day, where remain in vegetative growth until decreasing and may reach 6m height before flowering.8 hr day + low temp (below 22ºC) also delay flower.
169 Soil, Nutrition and moisture: Transp. 3Soil, Nutrition and moisture:Sandy loam-clay loam or in peat and muck soil, 6-7 is the optimum pH but the range can be extended to 5-8 since it is moderately tolerant to salt and alkaline.Needs kg, kg, and 60 kg of N P and K respectively are required/ha.Higher doses of N are more applicable for light soil and for early spring planting. Also 27.4 million ton/ha of barn yard (مخلفات الحبوب) or 9-11 million ton/ha of poultry manure are recommended.Supplemental watering is needed to reach to mm/season that mainly done by sprinkles. At tasseling and silking water stress could be of great negative effect on plant development that causes stalk rot, low plant height, low ear development and so the yield. So irrigation when 40% of the available soil water is depleted and not after that. Growth: normally hybrid seeds produce more vigorous and higher yield.
170 Treatments against pests are recommended 2 Treatments against pests are recommended cm depth x 90 cm between rows x cm between plants.Thinning can be done when plants reach up to 10-15cm height.Pollination by insects or gravity → poor fill kernels resulted of poor pollination where temp is more than 36ºC with hot dry wind or at water stress → = or nonviable pollens. 19 days after pollination → ears ready as vegetable then 30 days to mature.N stress during maturity → shriveling of kernels while excess → lodging.
171 Days to tassel emergence No. leaves visible at initiation Table Effect of photoperiod on 'major belle' a puerto rican cultivarNo. leaves at tasselingDays to tassel emergenceNo. leaves visible at initiationDays to tassel initiationPhotoperiod a(hr)19.8669.5261019.29.7271325.28717.05016Source: Arnold (1969)a :24 ºC (75 ºF) at 32,000 lux (3000 fc).
172 Average number of kernel Grain yield (g/plant) Table Photoperiod and temperature effect on corn (harrow 691 hybrid) yield.aWt/kernel (g/dry wt)Average number of kernelGrain yield (g/plant)Total plant dry wt (g/plant)Treatment0.1923795717430ºC/10 hr day0.1713995525030ºC/10 hr day +10 hr low light0.28142711422020ºC/10 hr day0.33860719447820ºC/10 hr day +0.02291-27LSD 5%a : Data from Hunter et al. (1977).
173 Planting to fourth leaf stage warm Fourth leaf to ninth leaf stage Table Effect of cool and warm temperatures on development golden cross batman sweet cornTemperatureTreatment periodCoolWarmPlanting to fourth leaf stagewarmFourth leaf to ninth leaf stageAverage number of leaves14.914.317.5Main stalk9.69.812.312.6Below first ear188.8.131.52.9Above first ear184.108.40.206.3Showing at tassel initiationSource: Arnold (1969).a Warm: 35ºC days/26.7ºC nights (95º/80ºF); cool: 21ºC days/12.8ºC nights (70º/55ºF); day length: 14 hr at 32,000 lux (3000 fc)
174 Stages in growth of Corn 25507585100011520406080100LeavesStalkCobKernelTasselingSilkingSweet corn harvestMature seeds% of total GrowthDays after Emergence
175 Harvest and storage:At 16ºC (storing conditions) corn remain in a marketable conditions for 5 days while at 29ºC→ 1-2 days that is incase of milky harvesting or fresh which can be eaten freshly or freezed or canned.Harvesting done by machines, at the early morning during cool temp condition of the day then immersed in ice water to keep temp lower than 10ºC then transfer into cooler to be stored at nearly 0ºC and high RH, so as to decrease the rate of sugar transferred into starch → ↓ sweetness.Under vacuum cooled → ears will be wetted down before packing in ice condition to keep satisfactory quality for 1 week while at 10ºC → 2 days.Development of CVs that has gene sugery 1 which prevents starch building from sucrose and that has gene brittle 1 which inhibits breaking down of sucrose into fructose. Both 2 genes allow sweet corn to remain sweet for several days without refrigeration and extend the time for harvest.
176 Pest and diseases: Nutritive value: Corn ear → insecticide worm, smut that can be controlled by resisting cultiovars and crop rotation, ear mold or pink rot which needs increase irrigation and high temp, sugar cane mosaic virus, and by insects.Nutritive value:High in energy, inprovitamin A, low in essential amino acid lysine, but new cultivars have developed showing high lysine content through out the gene (Opaque 2.) which also increases tryptophan proportion.
177 Lettuce Family:Compositae or Asteraceae Genus :Lactuca Species :sativa Origin:East Mediterranean sea (Asia minor, Iran, Turkistan area). Cultivated type is probably derived from wild lettuce: Lactuca serriola.Botany:Annual herbaceous plant, its most often grown as leafy vegetable, with milky juice. There are six commonly recognized Cultivar Groups of lettuce which are ordered here by head formation and leaf structure; there are hundreds of cultivars of lettuce selected for leaf shape and colour, as well as extended field and shelf life, within each of these Cultivar Groups:
178 Cultivar Groups subdividing into: Crisphead, also called IcebergButterhead forms loose heads. Its leaves have a buttery texture.Romaine, also called Cos.Looseleaf has tender, delicate, and mildly flavored leaves.Stem lettuce "stem-use” types (called celtuce).(Having as basic chromosomes number of 8-9 (as n)).
179 Culture:Cool season crop forming heads at 10-20ºC as mean temp, but at 21-27ºC lettuce bolting.It is required cool nights for good quality avoiding bitterness that related to high temp building of starch.High moisture and low temp means good head formation, while low moisture and high temp leads to disorders formation as tip burn where tips of inner leaves in head show necrosis.Well drained fertile soil of pH 6 is most desirable for growing lettuce, fair tolerance to salts needing about kg of N from various Article.Seeds are sown ½–1cm depth x 35cm between rows x 20-30cm between plants (thinning done when plants reaching this density).
180 Possibility of low space for leafy crops mainly transplanting. Also, seed can utilize about 8kg of P, 130kg of K, and 22 of Ca/ha depending on nutritional status of soil which can be incorporated during soil preparation except N that can be divided into 2-3 parts; one at preparation, 2nd after thinning, and the last one month before harvesting (50% of crop is realized at last 2 weeks).Moisture is highly needed along growth cycle, but in frequent manner since lettuce has shallow root system.It is rich in Vitamin A, C and good in minerals as Ca and P.
181 Harvest and storage:Needs days as cycle during summer to fall, and days during winter and spring, it is highly perishable crop since it has very high water content. So, it should be precooled to about 1ºC x 95-97% of RH, either incase of storing or transport → remain for days in good conditions while fast deterioration occur with ↑ temp.Pests and diseases:Aphids: transmit other diseases, cut worm, army worm, cabbage loopier, corn ear worm, leaf Hooper, spider mite.Mosaic (seed born disease).Spotted wilt.D.M., P.M., Sclerotina, Anthracnose, bottom rot.Tip burn is a physiological condition that causes lettuce to "die back" at the edges of the leaves (also rib discoloration). It results from a change in the moisture relationship between the soil and the plant. Clip off any brown leaf tissue and use the remainder of the leaf. Frequent light watering helps to prevent tip burn. Some varieties are resistant to this condition.
182 Days before First Harvest Growth expressed as leaf area per plant for spring, summer ,and fall lettuce.123456789101112706356494235282114Early SpringSummerFallDays before First HarvestMean leaf area per plant-1000 CM 2
183 Cabbage and Cauliflower Family:Brassicaceae (also called Cruciferae)Genus:BrasicaSpecies:OleraceaCultivar group: Capitata, BotrytisCalled Cruciferous vegetables, they are one of the dominant food crops worldwide.The family contains well-known species such as Brassica oleracea.Brassica oleracea var. Capitata cabbageBrassica oleracea var. Botrytis cauliflower
184 Origin:Native to the Mediterranean region, where it is common along the seacoast. Originated from wild type Brassica oleracea var. sylvestris that presented along the Mediterranean Sea coast and along the Atlantic coast where cabbage from Western Europe, and cauliflower from Mediterranean sea coast.Cabbage was used for medical purposes as diarrhea and headache and as a remedy for poisonous mushrooms.Botany:They are biennial herbaceous crop (but if leafy crop it becomes annual), propagated sexually by seeds, pollinated by insects forming Silique fruits in which seeds are found.They are cool season crops forming qualified crop as growth in low temp.
185 Cabbage: show best growth at 15-20ºC, over 25ºC growth is arrested having 0ºC as minimum, but cabbage with hardening can survive up to -10ºC (for short period of time).Young plants of less than 6mm in stem growth can tolerate colder and hotter temp than older plants.After juvenile stage, the plant flowers when temp less than 10ºC for 5-6 weeks, while if temp is lower, the plant will flower in shorter period of time.So it is not photoperiod sensitive, but vernalization effect.
186 Cauliflower: early type (snow ball) can form curd at 17ºC as optimum, when having 14-20ºC → is good range for increasing quality curd, while from 20-25ºC → poor quality curd, so selection provides cultivars that can show good curds at temp higher than 20ºC which is good for tropical conditions.Early type doesn't need cold temp for curd.Late type (winter): it requires cold period before heading, so it should be sown not too late, and its better to use intermediate types that form heads below 10ºC.Early types show not true flowers when curd but undifferentiated shoot apices while winter or late one (which need cold temp treatment) show true floral primordial.The East Indian cauliflower is tolerate to high temp and to high RH% since it is resulted from various selections → adaptation to local climate and for earliness in addition to crossing of local x snow ball resulting in Indian cauliflower as Early Potato, Early Market and Early Benares which can produce good curds above 20ºC having 30ºC as maximum → (large curds) and having 23ºC as minimum. This doesn't need low temp as snow ball or winter to make seeds (16ºC is low enough to give seeds).
187 Green curds: excessive exposure to sunlight → chlorophyll. Types of defects in cauliflower curd:Blindness: injury by low temp, slightly above 0ºC when plants are at 7-leaf stage, or by freezing injury during early curd stages → x curd.Button: as a result of transplanting quite large transplants which directly go into the generative of flowers phase producing smaller than normal heads. Also poor environmental conditions which arrest vegetative growth → buttoning.Ricey: disorder of head (like boiled rice) as a result of development of small white flower buds which related to high temp (20-25ºC) during curd and more by rapid growth and heavy N side-dressing.Leaves in curd: as exposing to warm temp after curing → reversion to vegetative growth.Green curds: excessive exposure to sunlight → chlorophyll.Head shape: low temp (below 14ºC) promotes flat heads, while high temp (over than 20ºC) promotes formation of conical shaped heads.
188 Propagation:Either by direct seeding or transplanting, this is more practiced in cold climate and for hybrid seeds.Hardening of seedling before transplanting is important by being exposed gradually into low temp for about 10 days or by water stress or by both together. Then transplanted at 90 x 90 cm apart incase of large heeded cabbage or at 45 x 90 cm incase of small heads, watering of soil during or directly after transplanting is important.Soil:Cole crops grow well in all soil types, but do best in rich sandy loam, loam or silt loam which should be slightly acidic to slightly alkaline (pH of ), but if too acidic → lime attition.
189 Fertilization:They need about 110 kg, kg, kg of N, P and K respectively.Quantity to be added depends on richness of soil.Nitrogen shortage leads to low yield, delays maturity, low quality, and low firmness.Phosphorus shortage causes "whiptale" of cauliflower.Harvest and storage:Reach the maturity of full head size, which is related to cultivars and can be detected by experience of farmer.Crop should be stored at 0ºC x % RH where cabbage can remain up to 6 months while cauliflower up to 1 month.Nutritive value: rich in vitamin C, provitamin A, good level of protein.Main pests are aphids, warms, botrytis, P.M.
190 Vegetables legumesFamily: LeguminosaeLegume: botanically is a plant in the family Leguminosae.Annual or pereninal dicotyledon.At immature stage → vegetables eating pods and/or seed.List of vegetable legumes in pages 253, 254, 255.They are mostly of alternate, compound pinnate leaves showing butter fly flower.Pollinated either by self or cross pollination with mainly Bees for cross.They are Hypogeal (cotyledon as in pea → remain under soil surface) or Epigeal (over soil surface) as beans.
191 Nitrogen Fixation:Legume plants are notable for their ability to fix atmospheric nitrogen, due to a symbiotic relationship with certain bacteria known as rhizobia found in root nodules of these plants, through out nitrogenase enzyme that presented in bacteria and activated by Fe and Mo.When plant dies, N levels in the soil will be increased.
192 Peas Pisum Sativum Origin and Botany: Originated in the eastern Mediterranean region, and in the near east.Annual herbaceous plant, with a life cycle of one year. It is a cool season crop grown in many parts of the world; planting can take place from winter through to early summer depending on location.Peas have showing alternate leaves.Peas have both low-growing and vining cultivars. The vining cultivars grow thin tendrils from leaves that coil around (climb) any available supportTerminal tip is tendril → called indeterminate, or could be of bushy or dwarf growth habit → called determinate, showing flower at the axil of leaves which usually self pollinated.Showing Blooms at 9-10 leaves in early cultivars and at leaves in late cultivars, having 2-10 seeds /pod.Seeds can be smooth or wrinkled.
193 Culture:Cool season crop, grown in wide range of soil type from light sandy loams to heavy clays with presence of draining conditions since pea can not tolerate water soaking status, having pH range of as optimum.In Temperate regions peas planted in spring to avoid sever wind or in late fall where frost effect is still tolerable.In Tropics and Subtropics peas planted in high elevation which remains cool. They are sown at 2-4 cm depth x 5cm between plants x 38cm between rows using kg/ha of seeds showing on increase in germination rate up to 18ºC then it will decrease.If the field has not been used for cropping of peas in the resent years then → seeds should be inoculated with Rhizobium bacteria before being planted.
194 Staking is needed for climbing types, if dying → yield is lower. N, P added at rates of 90 kg/ha, and about 100 kg/ha respectively, they are mended as preplanting since its later in N fixation will be used.If soil status is of low K, then a balanced fertilizer of NPK will be used.Peas grow best at mean temp of 13ºC-18ºC → mature in days according to cultivar.Noticing that before bloom crop can with stand some frost while at flowering and pod production become susceptible to frost.
195 Harvest and storage:At full pods stage, not hard or starchy seeds, under cool conditions, it can remain for longer period than at warmer condition where starch accumulates rapidly, (quality lasts for few days), while with cool conditions it can last for longer period.Either by hand, or machine and separations by flotation → various species gravity, then after harvest → should be cooled quickly at 0ºC to decrease the conversion of sugar into starch and to decrease respiration rate.So, seeds can be stored for 3 weeks at 0ºC, or for 2 weeks at 5ºC especially in controlled atmosphere (5-7% CO2).
196 Pests and diseases:The pea leaf weevil is an insect that damages peas and other legumes, (damage plant and pods).Aphids, leaf miner, wire worn, nematodes.Bacterial blights: caused by water socked lesions, P.M., D.M.Yellow leaves, pea mosaic as viral diseases → stunting and mottling of leaves.Crop rotation can help in controlling diseases.
197 Common Bean Phaseolus Vulgaris Origin and Botany Originated in Central America (from Mexico to Pero).warm season crop (in tropics).Its is an herbaceous annual plant with alternate trifoliate leaves.Indeterminate and bushy or dwarf, grown up to fleshy pods (immature seeds).Indeterminate reaches to 2-3 m height, while determinate reaches from cm, where after 4-8 leaves terminating with inflorescence showing self pollination (self fertilized).Forming 4-12 seeds/pod of 0.7 – 1.5 cm in length /seed, weighting 0.2 – 0.6g/seed.
198 Culture:Warm season crop (that makes germination faster), it germinates at 30ºC as optimum, and stops at 10ºC of soil temp.At 35ºC germination % is decreased, and if air temp less than or equal 10ºC, it can injure seedlings.They are planted at 5-10 cm apart x between rows x 2-4 cm depth using kg/ha, which should be treated with fungicide (pesticides) before being seeded. Handling of seed is important since cracked seed coat or cotyledon → have low germination %.Light airy of good drainage soil is the best for growing and for bacterial activity of N-fixation.Inoculation with Rhizobium bacteria is important if the field was not cultivated with been in the recent years.Preplanting fertilization of kg of N/ha, 100kg/ha of P, 70kg/ha of K can be dressed beside row of plants. Also well decomposed manure be used.
199 In temperate regions, it is planted in spring after frost danger finished. In hot humid tropics diseases will develop rapidly, so plant it in medium rainfall areas.Indeterminate beans need support to climb.Moisture stress will decrease yield drastically at flowering and pod formation.Increase temp at flowering → makes abortion; hot dry winds destroy the delicate flowers.Some cultivars have been developed to tolerate high temp as California Red that set pods at 38ºC at anthesis stage
200 Harvest and storage:Need days to harvest pods according to cultivar, dwarfing cultivars needs less time.The harvest of pods is when plant have grow to 3/4 of their maximum length (full size), and when seeds are succulent.Storage: at 5ºC can remain up to 25 days, below this range (0-2.5ºC) induces chilling injury within days.Above 5ºC the storage life decreased as temp increased, where at 25ºC pods will be at fair condition after 4-5 days.
201 Pests and diseases:Anthracnose of common bean: causing circular sunken spots with black edges and pinkish center → free seeds.Common bacterial blight: Red spots on stem and pods → may cause plant defoliation in sever cases.Bean common mosaic virus: Curley top and mosaic viruses → induces stunt, deformed, and curling of leaves. It is transmitted by aphids forming necrotic mosaic patterns on leaves.Aphids, Mites, Thrips, White fly, and nematodes.P.M. that can be controlled by sulfur dust Rust in cool region → resistant cultivars are used.Nutritional value:Good source of cholesterol-lowering fiberIt provides virtually fat free high quality proteinRed lima Bean which is almost like common Beans.
202 Tomato Family:Solanaceae Genus:Solanum Species:Lycopersicum Synonyms: Lycopersicon esculentumOrigin:Native to South America, Mexico and Central America.Botany:Tomato plants are vines, typically growing above the ground if supported.Tomato plant vines are typically pubescent, meaning covered with fine short hairs. These hairs facilitate the vining process, turning into roots wherever the plant is in contact with the ground and moisture, especially if there is some issue with the vine's contact to its original root. It is Tomato plants are dicots, herbaceous, annual shrubby plant in temperate zones, or could be perennial of short life in tropics.Can be determinate (bushy compact growth), and indeterminate.
203 Climate:Adapted to wide range of climatic and soil conditions → so it shows wide distribution all over the world either protected or in open field of tropics.Temp means should be over 16ºC, but if temp drops below 12ºC tomato gets chilling injury especially if it remains for long period below this degree.The optimum range is 21-24ºC, but the minimum soil temp for seed germination is 10ºC, while 30ºC is optimum and 35ºC is maximum.Also, if light intensity is more than 1000 foot candle → it will affect negatively on growth and flowering, but if light intensity falls down → then supplemented light is needed to increase the photoperiod.
204 Flowering and fruit set: If temp degree is more than 38ºC for 5-10 days → this will cause poor fruit set since the pollens and eggs will be destroyed.After anthesis (flowering), if temp is more than 38ºC for 1-3 days → this will also cause poor fruit set since embryo destroyed.If minimum night temp is more than 25-27ºC for few days → this will cause poor fruit set before and during anthesis except incase of tropical cultivars that can tolerate this level.At 10ºC or below → abortion.Using of IAA and gibberellins can increase fruit set avoiding puffy fruits by Gibb presence.
205 Fruit Ripening:Tomatoes are often picked unripe (and thus colored green) and ripened in storage with ethylene. Unripe tomatoes are firm. As they ripen they soften until reaching the ripe state where they are red or orange in color and slightly soft to the touch.Ethylene is a hydrocarbon gas produced by many fruits that acts as the molecular cue to begin the ripening process.Tomatoes ripened in this way (ripened in storage with ethylene) tend to keep longer but have poorer flavor and a mealier, starchier texture than tomatoes ripened on the plant. They may be recognized by their color, which is more pink or orange than the other ripe tomatoes' deep red, depending on variety.Optimum ripening temp is from 18-24ºC, but less than 13ºC poor ripening and slow, and below 10ºC chilling injury and → no fruit ripenes.32ºc green mature fruit will not formed red color since lycopen (one of the most powerful natural antioxidant) is inhibited → yellowish color of ripen fruit in storage.Also more than 40ºC as mean temp → fruit remains green since chlorophyll degrading mechanism is inactivated.
206 Culture:Soil: Sandy loam to clay loam of high organic matter content, pH range is from , plant can't with stand flood for long period, so well-drained soil is important.Planting in high beds avoiding using infested soil with nematodes or bacterial wilt, using also resistant cultivars to fusarium wilt strain and verticillium wilt in infested soil.Incase of poor soil, 112, 22 kg N, P, K /ha are used, incorporating about 11, 17 of N, P below seeds (during land preparation) and the rest as plants reach up to cm.Also manure is recommended and N is important to increase yield either direct seeding or transplanting at cm apart x m between rows for indeterminate and x for bushy plants.
207 2.Moisture: over watering is detrimental, when plants are small → frequent watering produce low quality fruits, so frequent watering becomes less as plant gets older (because of more efficient root system).Roots can reach cm deep in the soil or more unless it will be blocked by hard pan or reach layer or water table.At cool conditions, the ETP from tomato field reach to 0.3 cm/day while at hot conditions → it reaches 1 cm/day, as ETP.B.E. Rot is physiological disorder related to un uniformity in water availability and to Ca deficiency.Harvest and storage:Tomato requires about days to start the harvesting of fruits (depending on the cultivar, climate condition = temp and photoperiod).For fresh market, it is harvested at fall green mature stage then ripened during transportation or in storage, which should occur at temp degrees more than 10ºC since below that temp chilling injury happens, as temp is more than 10ºC the rate of ripening will be faster.Light is also important for development of red pigment lycopene.
208 Days from mature green at 20ºC Table: Maturity stages of tomato ripening are:DescriptionDays from mature green at 20ºCStageStill ↑ in size, angular in shape, dull green, immature seeds that not germinate.-Immature greenBright green to whitish green, rounded waxy skin, seed embedded in gel, they are mature and can germinate → only and not before this stage → can ripen.Mature greenPink color at blossom while the placenta is pinkish.2BreakerPink covering 10 – 30% of fruit starting from blossom.4TurningUp to 30 – 60% is of pink – red color.6PinkUp to 60 – 90% is of pink – red color.8Light redAt least 90% of fruit of red color.10Red
209 Storage:Mature green should be stored at 13-18ºC x 85-90% of RH where no chilling injury and fruits will ripen at temp degrees more than 18ºC.Rapid ripening up to 30ºC, but more than that temp, red pigment not formed, fruit color is orange to yellow.Pests and diseases:One common tomato disease is tobacco mosaic virus, and for this reason smoking or use of tobacco products are discouraged around tomatoes. The signs are blotchy yellow and green spots on plant leaves.Various forms of mildew and blight are also common tomato afflictions as verticillium and fusarium wilt which causes yellowing of leaves and reddish brown color of vascular stem system.Nematode that makes knot, like swellings of roots → but resistant cultivars are available.Phytophthora as soil born diseases due to wet soil.Bugs, worms, and mites.Thrips that cause spotted wilt vines.Tomato Yellow Leaf Curling Virus (TYLCV).
210 Nutritive value:Tomato fruits produce the most powerful lycopene, carotene, anthocyanin, and other antioxidants.Ripened tomatoes are good source of vitamin A (provitamin), and when ripened on vines, it’s a good source of vitamin C, while if its red off → it has low vitamin A and vitamin C content.As weeds parasites: orobanche:
211 Eggplant Family:Solanaceae Genus:Solanum Origin: Native to India. Species:melongenaSolanum melongenaOrigin:Native to India.Botany:The stem is often spinyThe fruit contains numerous small, soft seeds, which are edible, but are bitter (even if mature or low water levels) because they contain (an insignificant amount of) nicotinoid alkaloids, unsurprising as it is a close relative of tobacco.It is a delicate perennial often cultivated as an annual.It grows cm height, bearing oval shaped or elongated oval fruits showing indeterminate growth.Most fruits are purple to blackish purple skin color with white flesh.Yellow skin is the indication of fruit maturity.
212 Climate:Warm season crop, so it needs continuous warm season during growth up to fruit maturity, having 22-30ºC as optimum, 17ºC as minimum → so night also should be of warm weather where pollen deformity increase at 15-16ºC, so it should transplanted during warm spring especially in northern hemisphere.Long fruit cultivars are more tolerant to high temp.Flowering starts after 6th to 14th leaves formation (early to late according to cultivar) noticing that eggplant is insensitive to day length for flowering.
213 Culture:Good light intensity is required.Preferring soil of pH from , avoiding flooding of water since it causes root rot.Light sandy soil if planted in early spring (get ready and warm earlier), or it can be planted in loam soil for late production.If rain fall is high, it is planted in raised beds and at water shortage → but this gives poor fruit color and bitter fruit taste.Optimum soil temp for seed germination is 30ºC having the range of 20-35ºC.Seedlings are transplanted at 2-3 true-leaf stage.Also, it can be propagated by layering of stem → adventitious shoots from immersed nodes, then rooting branches will be detached as new seedlings.IAA and NAA growth regulators (plant hormones) can be used for cuttings propagules.Requires 150 kg/ha of N, P, and K.
214 Harvest and storage:Needs from days from transplanting to harvest of first fruits that can continue at favorable conditions up to 2-3 month (according to cultivar, climatic conditions …).Also can be rejuvenated by pruning back of unproductive diseased free plants then provide nutrients and water in proper manner.Harvesting done at full size fresh fruits (before seed maturity which becomes yellow in color).Storage:At 10-15ºC x 85-90% RH → remain 10 days with good quality, while below 10ºC chilling injury occurs then after removing from such storage conditions, pitting and decay occurs after several days at room temp.
215 Pests and diseases:Many pests and diseases which afflict other solanaceous vegetables, such as tomato, pepper , and potato, are also troublesome to eggplants. For this reason, it should not be planted in areas previously occupied by its close relatives.Four years should separate successive crops of eggplantsIn tropical regions: eggplant Lace lug, aphids, mite leaf hoppers, flea beetles, fruit borer, nematodes.In temperate regions: flea beetles, potato beetles, aphids, spider mites, nematodes.Black wilt, Anthracnose, verticillium (fungal disease), mosaic virus, fruit rot.
216 Pepper Family:Solanaceae Genus:Capsicum This Genus Capsicum includes many species, as:1- Capsicum annuum: Sweet pepper2- Capsicum frutescens: Chili pepperOrigin:Native to Mexico, Central America, and Northern South America (Andes mountains)..
217 Botany:Annual in temperate regions, and perennial in tropical regions.Self-pollinated crop (on Bell-like Pod-like berry fruits, (pungent or non pungent) cultivars.Needs slightly high temp than tomato for growing since it is more sensitive to cool and to wet weather.Hot cultivars are more tolerant to high temp than sweet cultivars.Below mean of 16ºC → no fruit set as well as over 32ºC.Maximum temp for fruit set of bell pepper occurs between 16-21ºC.Culture:Warm season crop, so it needs warm climate and it has long growing season showing tolerability to extreme hot weather than tomato or eggplant.Favoring light, fertile, well-drained soil.Can be transplanted or seeded directly, but after frost period showing optimum germinating temp of 30ºC and 35ºC as maximum.
218 4.They are planted at 40-60 cm x 75-90 cm between rows. 5.It needs: kg/ha of N, and 22 kg/ha of P, while K is not added unless its availability in soil is low.Harvest and storage:Needs days from transplanting to fruit harvest (immature) at full size and still green incase of bell pepper.Also hot pepper is harvested for fresh consumption while still green, but for processing it is harvested when ripe (red color).The best storage temp is 7ºC-10ºC where green pepper can remain days below this range → chilling injury causing cell to die and fruit decay.
219 Pests and diseases of pepper: Flea beetle, Cut worms, aphids, vegetable weevils, grace hoppers, wire worms, corn seed maggots, leaf miner, and caterpillars where these mainly damage plant and/or fruit.Tobacco mosaic virus, tobacco etch virus, potato Y virus and cucumber mosaic virus, curly to P virus that causes curl up ward and yellowing of old leaves, spotted wilt which causes die back of growing plants.Nematodes: gall formations on the roots.Phytophthora root rot: rotting of roots under high temp and high soil moisture, so good management of water application is important.Seedling damp-off by Rhizoctonia solani.Pythium and Phytophthora which attack seeds and seedlings before being emerged throughout the soil.
220 Nutritive value:They are rich in pro vitamin A, vitamin C at mature stage.Capsecin is the active component of chili peppers, it is responsible for pungent flavor, it concentrates in septa and placenta tissues of fruit and in seeds of hot pepper.
221 CucurbitsGenerally:Plants of the family Cucurbitaceae are called cucurbits.Most are climbing (twining, tendril-bearing plants) or prostrate (as gourd).They are dicotyledonous, tropical or subtropical (few of temperate origin).Most of the plants in this family are annual vines, some are perennials (Cucurbita ficifolia) = figleaf or buffalo gourd = يقطين).All are frost sensitive.Mainly for fruit consumption.Flowers are unisexual, with male and female flowers on different plants (dioecious) or on the same plant (monoecious).
222 Sex expressions are:Hermaphrodite: has functional ♀ and ♂ flower parts (perfect flower).Monoecious: plants has both ♂ and ♀ flowers.Gynomonoccious: plants have some hermaphrodite and some ♀ flowers.Andromonoccious: plants have some hermaphrodite and some ♂ flowers.Trimonoccious: plants have hermaphrodite and ♂ and ♀ flowers.Gynoecious: plants all flowers as ♀ flowers.Anaroecious: plants all flowers as ♂ flowers.Dioecious: have ♂ flowers in plants and ♀ on others
223 Most cucurbits showing extensive root system, trailing stems with branches arised from nodes, simple leaf of 3-5 lobes showing also tendrils that born from leaf axil (except in bush or dwarf squash cultivars).Fruit is an inferior berry or pepo.Considered as warm season crop, day-neutral crop, as photoperiod (12 hr days).
224 Family:Cucurbitaceae Genus:Cucumis CucumberFamily:CucurbitaceaeGenus:CucumisSpecies:sativusCucumis sativusOrigin:Cucumbers originated in India, since Cucumis hardwickii is the wild type of cucumber that found in Himalaya.
225 Botany:The cucumber is a creeping vine that roots in the ground and grows up trellises or other supporting frames, wrapping around ribbing with thin, spiraling tendrils. The plant has large leaves that form a canopy over the fruit.It is annual herbaceous cultivated for immature fruits, prostrated reach up to 1-3 m, 3-5 lobed simple leaves and angled stems.It is monoecious, where under long days and high temp, it gives high number of ♂ flowers than ♀ flowers, but under short days it gives high number of ♀ flowers than ♂, although it is day neutral.The main vector of pollination is bees while the parthenocarpic fruit cultivars don’t need pollination.Gynoecious lines are used to produce F1 hybrid seeds using of ethephon (spray) → only ♀ flowers are produced show white or black spins or fruits, white is the marketable character since it retains the green color for long period, while black spin fruits are used for picking since better color retention will be occurred as fruits kept in brine.
226 Culture:Warm season crop showing best growth at 18-30ºC, and suffer from chilling injury below 10ºC.It needs well drain fertile loam soil of pH range fromTransplanting of seedlings: if naked, it is difficult (but with growing media, it becomes good), or by direct seeding, (hard to transplanting since the rate of vegetative growth is higher than root formation for new transplantings).Germinating at 25-35ºC as optimum temp needs about 3 days.Spacing is from cm in rows x 1.2 m apart or in beds of cm width.It needs 70, 110 and 70 kg/ha of NPK, where N can be divided in two halves, first halve during soil preparation, and the remainder is applied either frequently (with irrigation water) or as a side-dressing after plants are thinned at 3-4 true-leaf stage.Adequate soil moisture is needed for good yields (since fruit has 95% water) especially in tropical (dry regions), when temp increase during plant development in the growing season where the minimum of 400 mm of water should be provided to ensure good yield production.
227 Harvest and storage: Storage: For fresh market: fruits are harvested before reaching fully elongated and mature seeds (when seeds are still succulent).For picking: fruits can remain on plant for longer period.A period of 55-70days is needed from planting to first harvest according to climatic conditions, cultivar …Storage:If storage temp lower than 10ºC → chilling injury suffering and shriveling of fruits can occur, so the optimum storage condition is 12ºC-13ºC x 95% RH, while at 15ºC fruits yellowing and faster degradation are occured.If fruits are kept in plastic packages, then fruits need longer duration since plastic bags retards moisture loss.
228 Pests and diseases: Nutritive value: Cucumber beetle, squash bug, melon aphids, Nematodes, fusarium wilt, Anthracnos, D.M., P.M., curly top mosaic virus, squash mosaic virus, Botrytis, Sclerotia.Nutritive value:High water content, about 96%, so it is a good source of minerals and also vitamin C.Bitterness is related to cucurbitacins that concentrated in the upper part of fruit (near connection to stem) and also influenced by growing conditions as water stress.
229 Family:Cucurbitaceae Genus:Cucumis MuskmelonFamily:CucurbitaceaeGenus:CucumisSpecies:meloCantaloupe: Cucumis meloHoneydew: Cucumis meloOrigin:Tropical and subtropical west Africa as primary origin, while Iran, southern Russia, India and east China is the secondary one.
230 Botany:It is monoecious or andromonoecious, annual plant, showing long trailing vines (prostrated) but shallow lobed (more rounded) leaves.Varieties of Cucumis melo includes:The Cantalupensis group includes the European "cantaloupe" with skin that is rough and warty, not netted.The Inodorus group includes "honeydew melon", "casaba melon" or "winter melon". These have smooth rinds and do not have a musky odor. Honeydew has a smooth, white rind and sweet green flesh. When eaten, the texture is similar to a reticulated cantaloupe, but the flavor more subtle and sweeter. Classified sometimes as Cucumis melo inodorus. شمام أصفر شتويThe Flexuosus group, also known as "snake melon". المتطاولThe Reticulatus Group includes the "netted melon", "American" cantaloupe". Other common names are the "Persian melon." المشبك (الإيراني)
231 5.The Conomon group is the "Oriental pickling melon". لامع 6.The Chito group is the "garden melon." Also known as "mango melon". منجا7.The Dudaim group is the "vine pomegranate". رمانThese vary in fruit size, shape, smooth or sutured or netted skin, white to green to yellowish green to yellow to yellowish brown to orange with yellow or green back grounds, that at maturity accumulate sugar in fructose, glucose and sucrose forms which upon ripening becomes fleshy soft and release aromatic essences.
232 Culture:Warm season crop that needs days from planting to harvest.Having 18ºC-24ºC optimum temp for growth favoring arid conditions (avoid fungal diseases).Needs deep well-drained fertile soil 7-5 light alkaline pH since it is sensitive to acidic conditions.Light sandy soil or sandy loam soil gives early yield, while good yield obtained from heavier soils but not clay or peat soil.Its recommended to add kg/ha, kg/ha of N and P, and some K if its availability is low, half of the quantity is placed beside seeds, and the rest is side-dressed shortly after thinning (at 4-6 true-leaf stage).They are planted cm depth x cm apart x cm between rows or in beds.Adequate moisture of soil is required up to last week before fruit begin to ripen.At 30cm spacing: 1-2 fruits/plant at the same time, if more than 2 → then small fruits and of low s.s.
233 Harvest and storage:In cantaloupe: the formation of abscission zone between fruit and peduncle, the change in the color of the area touching soil into yellow, and slight aroma to be smelled from blossom end.In Honeydew: change in color to yellowish white, waxy feel, and slight aroma from blossom end, but there is No abscission zone as in Persian melons.Both cantaloupe and honeydew are harvested for shipment before ripe eating stage, and then at room temp, it controls its ripening in few days, while honeydew needs ethylene treatment → as its soft from blossom end, and contains aromatic compounds.So, cantaloupe and honeydew are recording 8-14% and 10-16% of total sugar content respectively.
234 Storage: In the case of cantaloupe that doesn’t need Ethylene: It needs directly hydro cooling in ice water to decrease respiration rate, so low sugar loss, then transfer it to 10ºC storage place.Hard ripe fruits should be stored at 4-5ºC to fasten ripening for 4-10 days, then at 15-16ºC from 1-2 days x 95% RH.In the case of honeydew, the following treatment:Unripe mature melons: with white back ground, and some light green color showing fine hairs → no aroma and hard blossom end → so it can be treated with 200ppm ethylene gas at temp degrees > 20ºC.Initiated ripening: white back ground and slight wax surface, blossom end is slightly springy and had a slight aroma → ethylene gas treatment at 200ppm is not essential but could be beneficial.
235 c.Ripe fruit: creamy white color back color and waxy surface, total blossom end is springy with good aroma → no ethylene treatment.d.Slightly over ripe: creamy white to pale yellow back ground color, and quite waxy surface, strong aroma but the flesh is soft → the quality is lower than (ripe fruit above) but still edible.d.Over ripe: entire yellow surface, soft and strong fermented odor, soft flesh, springy and mealy → not edible.So, honeydew doesn’t need precooling, but after ethylene treatment of unripe in (a),stay it at 16ºC from 2-2½ day, then at 7-10ºC, from 3-4 days, while in (b) and (c), they can be stored at 7-10ºC from 2-3 weeks in 85-90% RH, but below 5ºC chilling injury occurs.
236 Pests and diseases: Nutritive value: Aphids, green peach aphid, cucumber beetle, leaf-hopper, leaf miner, red mite nematodes, wire worms, and seed maggot of corn.Pythium, Rhizoctonia attack seedlings, fusarium, phytophthora, alternarica which caused blights, P.M, D.M.Bacterial wilt that transmitted by cucumber beetle.Viral diseases: cucurbits mosaic viruses transmitted by aphids or seeds.Nutritive value:Rich in β-carotene: against lung cancer.Cantaloupe melons are a good source of potassium, Vitamin A, and folate.Useful laxative
237 Family:Cucurbitaceae Genus:Citrullus Water melonFamily:CucurbitaceaeGenus:CitrullusSpecies:lanatusCitrullus lanatus or Citrullus vulgarisOrigin:Originated in southern Africa, where it is found growing wild, now found native in north and west Africa.Botany:Monoecions, annual, large pinnate lobed leaves, give sweet juice, oblong or ellipsoidal or spherical fruit reach to or more than 12kg/ fruit, flesh may be of white, yellow, pink to red color at mature stage.This flowering plant produces a special type of fruit known as a berry, which has a thick rind (exocarp) and fleshy center (mesocarp and endocarp).Seeds may be white, greenish, yellow, brown, red or black containing high quantity of CHO, fats, and protein.
238 Culture:Warm season crop, needs long growing season (4 months of frost free weather).Temp degrees over 21ºC are good for growth.Good draining, sandy loam, to loam soils, is preferred, then heavier soils can be used, but with avoiding continuous use of the same land except if cultivars are resistant to fusarium wilt.So, crop rotation once every 4-6 years is good.If you have Nematodes with Fusarium → rotation done each 10 years.Its recommended to add kg/ha, kg/ha of N and P respectively, and some K if its availability is low following the same process as muskmelon.
239 Planting density: 1-2 m in rows x 2 Planting density: 1-2 m in rows x m apart over a beds after thinning which should be done carefully.Optimum soil temp for fastest germination is 25-35ºC, where at 20ºC it needs 12 days, and at 15ºC → poor growth.Minimum of 380 mm of water are needed in light soils (since this plant has deep roots), while in heavy soils, crop quality may be less.Since F.C. condition maintain for longer time, ♂ flowers are formed firstly then ♀ flowers, which will be pollinated by bees, so hives of bees are necessary.Low quality fruits are related to poor pollination.Pruning to 2 or 3 fruits/plant is necessary for larger size fruits and high sugar content.
240 Harvest and storage:Needs days according to, cultivar and growing conditions as temp.Fruits normally harvested when the flesh is sweet but not over ripe.Ripeness is related to the following criteria:The touched part to the soil changes into light yellow color.Thumping where immature fruits give a high pitched sound and mature fruits give low pitched sound.The tendril that directly opposite to fruit peduncle becomes brown and dry.Also samples from time to time to taste since most fruits of a comparable size have same stage of ripeness.Also refractive index of the juice that measure the percent of soluble solids which should be at least 10.5% at the center of fruit which supposed to give high percent, then the next highest percent is in the blossom end, then in the upper side, while the bottom (ground spot) and stem have the lowest.
241 Storage: Pests and diseases: Warm conditions that needs 13ºC-16ºC storing temp for 2 weeks to avoid chilling injury.If needed to be stored for longer period, then 7-10ºC is needed.Below 10ºC → flesh color fades.Also 80-85% RH is sufficient since water loss through waxy rind is very low.Pests and diseases:Aphids, cucumber beetle that attack leaves, stems and very young fruits, spider mites.Nematodes.Fusarium wilt, root rot by Pythium and Phytophthora spp.Viral diseases: Potyviruses that transmitted by leaf hoppers → cause curly and yellowing of old leaves and stunting growth and dark green color of new leaves. Watermelon mosaic virus transmitted by aphids → cause molting of leaves and stunt growth, with no fruits.Nutritive value: Good source of water and energy in dry conditions especially if sources of water are contaminated, and it’s a good source of fibers (for digestion).