The crop is grown from almost MSL to an altitude of 1500 m in tropical and subtropical regions, with an annual rainfall of 60-150 cm. Very high rainfall during its growth is harmful. When grown under hot weather, it is cultivated as an irrigated crop. The winter crop is planted from August to September. For organic farming of tomato winter crop has been found to be ideal.
Well drained sandy loam soil with high level of organic contents is best suitable for tomato cultivation. Soils with high acidity are not suitable for tomato cultivation. Three to 4 q of suitable lime can be applied in the field in an interval of three years to reduce the level of acidity to tolerable limits. There is a need to go for soil testing at the beginning of the crop season.
Land preparation
The land may be ploughed and harrowed 3 or 4 times to obtain a fine tilth. About 10 tonnes of Farm Yard Manure (FYM) or vermi compost/compost @ 1-1.5 t per acre is applied at the last ploughing. Green manuring is recommended for areas with assured rainfall and also for irrigated crop. Beds are prepared against the slope and after levelling the bed, field channels of 50 cm breadth are prepared at intervals of 1 m.
The crop is grown from almost MSL to an altitude of 1500 m in tropical and subtropical regions, with an annual rainfall of 60-150 cm. Very high rainfall during its growth is harmful. When grown under hot weather, it is cultivated as an irrigated crop. The winter crop is planted from August to September. For organic farming of tomato winter crop has been found to be ideal.
Well drained sandy loam soil with high level of organic contents is best suitable for tomato cultivation. Soils with high acidity are not suitable for tomato cultivation. Three to 4 q of suitable lime can be applied in the field in an interval of three years to reduce the level of acidity to tolerable limits. There is a need to go for soil testing at the beginning of the crop season.
Land preparation
The land may be ploughed and harrowed 3 or 4 times to obtain a fine tilth. About 10 tonnes of Farm Yard Manure (FYM) or vermi compost/compost @ 1-1.5 t per acre is applied at the last ploughing. Green manuring is recommended for areas with assured rainfall and also for irrigated crop. Beds are prepared against the slope and after levelling the bed, field channels of 50 cm breadth are prepared at intervals of 1 m.
This presentation provides a comprehensive overview of the cultivation of pomegranate (Punica granatum), a subtropical fruit crop of significant economic importance. It covers key aspects such as botanical characteristics, agro-climatic requirements, propagation, orchard management, pest and disease control, and post-harvest handling. The content is structured to support academic understanding and practical application in horticultural production systems.
General Information
- Order: Myrtales; Family: Punicaceae; Scientific name: Punica granatum L.
- Chromosome number: 2n = 2x = 16, 18; Synonyms include Punica florida, P. grandiflora, P. nana, and P. spinosa.
- Pomegranate is a subtropical, non-climacteric fruit with aril as the edible portion.
- Fruit type: Balausta; exhibits low maintenance cost and is salt hardy.
- Primarily grown for its nutritional and medicinal value.
Area and Distribution
- Native to Iran (Persia), now widely cultivated in India and other countries.
- India leads global pomegranate production, with Maharashtra accounting for ~73% of area.
- Other Indian states: Gujarat, Rajasthan, Karnataka, Tamil Nadu, Andhra Pradesh, Uttar Pradesh, Punjab, Haryana.
- Major export destinations: UAE, Netherlands, UK, Saudi Arabia, Russia, Bangladesh, Egypt, Nepal, Oman.
Industrial Uses
- Consumed fresh or processed into juice, syrups, jelly, and wine.
- Juice is rich in citric acid and sodium citrate; used in pharmaceutical and food industries.
- Seed oil has industrial applications.
- Medicinal uses include treatment for digestive disorders and as a dietary supplement.
Agro-Climatic Requirements
- Thrives in semi-arid to subtropical climates; tolerates altitudes up to 1800 m.
- Requires hot, dry summers and cool winters; frost tolerant during dormancy but injured below -11°C.
- Prefers well-drained sandy loam to deep loamy or alluvial soils; salt tolerant.
- Optimal temperature: up to 38°C; adequate irrigation is essential for fruit development.
Varieties Cultivated
- Major Indian varieties: Alandi (Vadki), Dholka, Kandhari, Ganesh (GB I), Muskat, Nabha.
- Other selections: G 137, P 23, P 26, Mridula, Aarakta, Jyoti, Ruby, IIHR Selection, Yercaud 1, Co 1.
- Varieties differ in fruit size, rind color, aril color, seed hardness, and juice quality.
Notable Varieties: Characteristics
- Ganesh: High-yielding, medium-sized fruit, pinkish flesh, soft seeds, agreeable taste.
- Alandi: Medium fruit, blood red arils, sweet-acidic juice, hard seeds.
- Dholka: Large fruit, greenish-white rind, sweet-acidic juice, soft seeds; prominent in Gujarat.
- Kandhari: Large, deep red rind, dark red flesh, slightly acidic juice, hard seeds; grown in Himachal Pradesh.
- Muskat: Small-medium fruit, thick rind, moderately sweet juice, rosy seeds.
- Nabha: Medium tree, yellowish smooth skin, 65% juice, light pink arils, medium soft seeds.
Propagation
- Vegetative propagation preferred to maintain varietal traits; cuttings are most common.
- Best time for cuttings: December–January (dormant period).
- Cuttings planted directly in nursery fields; rooting enhanced with 10,000 ppm IBA in lanolin.
- Air-layering (gootee) is also practiced for propagation.
Planting Operations
- Spacing: 5 x 5 m in square system; pit size: 60 x 60 x 60 cm.
- Pits refilled with topsoil, 20–25 kg FYM/compost, and 1 kg single superphosphate (SSP).
- Best planting time: January–mid-February (North India), monsoon season (South India).
Flowering and Fruiting
- Commercial bearing starts 3–4 years after planting.
- Multiple flowering seasons: 3 in Western India, 2 in Northern India.
- Anthesis occurs between 8 AM and 4 PM, peaking at 2 PM; stigma receptive up to 5 days.
- Fruit set rates: Dholka 63.8%, Bedana 63%.
Orchard Cultural Practices: Irrigation and Interculture
- Regular irrigation essential from flowering to harvest; drought stress causes flower drop and fruit cracking.
- Winter irrigation interval: 8–10 days; summer: 4–6 days.
- Drip irrigation recommended for efficient water use.
- Shallow inter-cultivation suppresses weeds and conserves soil moisture; mulching advised.
Orchard Cultural Practices: Manuring and Training
- Apply FYM and fertilizers as per plant age; split doses recommended for nutrients.
- Manure applied at monsoon onset; fertilizers in trenches around plants.
- Immediate irrigation after manuring enhances nutrient uptake.
- Training to multi-stem system from second year; regular pruning removes weak, dead, or diseased wood.
- Apply Bordeaux paste to pruning cuts to prevent infection.
Crop Regulation and Pollination
- Flowering regulated by bahar treatments: Mrig (June–July), Hasth (Sept–Oct), Ambe (Feb–Mar).
- Fertilizer and irrigation schedules adjusted for desired bahar.
- Pomegranate is both self- and cross-pollinated; hand pollination increases fruit set.
Harvesting and Post-Harvest Handling
- Fruits mature in 5–7 months; harvest indicators: color change, softening, flattening of ridges, metallic sound when tapped.
- Harvest with secateurs/clippers to avoid fruit damage.
- Sort fruits by size, maturity, and blemishes; pack in cushioned crates or baskets.
- Transport promptly to markets to maintain quality.
Physiological Disorders: Fruit Cracking
- Caused by boron and calcium deficiencies, irregular irrigation, and environmental stress.
- Cracked fruits are susceptible to insect and fungal attack, reducing marketability.
- Mrig bahar crop is more prone to cracking.
- Control: light irrigation, windbreaks, borax spray (0.1%), GA3 spray (250 ppm) in June.
Major Insect Pests
- Pomegranate butterfly (Virachola isocrates): larvae bore into fruit, causing rot and drop.
- Bark eating caterpillar (Indarbela quadrinotata): bores into trunk, causing webbing and stem death.
- Sap-sucking insects: aphids, mealy bugs, thrips; cause stunted growth and sooty mold.
Insect Pest Management
- Remove and destroy infested fruits and plant parts regularly.
- Neem-based sprays (NSKE 5%, neem oil 3%) deter oviposition; repeat applications as needed.
- Bagging fruits post fruit set prevents pest entry.
- Bark caterpillar: clean webs, insert petrol/kerosene-soaked cotton in holes, seal with mud; alternate sprays of Carbaryl, Quinalphos, or Methomyl as per recommendations.
Major Diseases and Management
- Leaf spot and fruit spot (Xanthomonas punicae): water-soaked, dark spots on leaves and fruits; can cause defoliation and fruit cracking.
- Fruit rot (Phomopsis sp.): affects flowers and young fruits, causing premature drop and spotting; prevalent in rainy season.
- Cultural control: use disease-free seedlings, proper spacing, organic amendments, and recommended NPK.
- Chemical control: spray Captan or Dithane M-45 (0.2%) for leaf spot; Dithane Z-78 (0.2%) for fruit rot at fortnightly intervals.
- Remove and destroy infected plant parts to reduce inoculum.
Objective Questions
Q1. Which of the following is NOT a synonym for Punica granatum L.?
A. Punica florida Salisb.
B. Punica grandiflora hort. ex Steud.
C. Punica indica Roxb.
D. Punica nana L.
Answer: C
Q2. Which pomegranate variety is specifically noted for having soft seeds and being an important variety of Gujarat?
A. Alandi
B. Dholka
C. Kandhari
D. Muskat
Answer: B
Q3. The best time for making cuttings for vegetative propagation of pomegranate is:
A. March-April
B. June-July
C. December-January
D. September-October
Answer: C
Q4. Which of the following bahar treatments is associated with the highest susceptibility to fruit cracking in pomegranate?
A. Mrig bahar
B. Hasth bahar
C. Ambe bahar
D. None of the above
Answer: A
Q5. The recommended basal application per pit at planting for pomegranate includes:
A. 10-15 kg FYM + 2 kg SSP
B. 20-25 kg FYM/Compost + 1 kg SSP
C. 5 kg FYM + 0.5 kg SSP
D. 30 kg FYM + 3 kg SSP
Answer: B
Q6. Which of the following is a major symptom of pomegranate fruit borer (Virachola isocrates) infestation?
A. Yellowing of leaves
B. Offensive smell and excreta at entry holes
C. Wilting of branches
D. Leaf curling
Answer: B
Q7. Which chemical is recommended for improving rooting in pomegranate cuttings?
A. Indole-3-acetic acid (IAA)
B. Naphthalene acetic acid (NAA)
C. Butyric acid (10000 ppm in lanolin)
D. Gibberellic acid (GA3)
Answer: C
Q8. The main edible portion of the pomegranate fruit is:
A. Mesocarp
B. Endocarp
C. Aril
D. Seed coat
Answer: C
Q9. Which of the following is NOT a recommended control measure for bark eating caterpillar (Indarbela quadrinotata) in pomegranate?
A. Cleaning webs around affected portion
B. Inserting cotton swab soaked in petrol or kerosene into holes
C. Spraying neem oil (3%)
D. Sealing holes with mud
Answer: C
Q10. The pathogen responsible for leaf spot and fruit spot in pomegranate is:
A. Phomopsis sp.
B. Xanthomonas punicae
C. Alternaria alternata
D. Fusarium oxysporum
Answer: B
This presentation provides an in-depth overview of the major diseases affecting brinjal (Solanum melongena), focusing on their etiology, symptoms, epidemiology, and management strategies. Emphasis is placed on the identification and integrated control of fungal, bacterial, and physiological disorders to ensure sustainable brinjal production.
Introduction to Brinjal Diseases
- Brinjal (Solanum melongena) is susceptible to several economically significant diseases.
- Major diseases include damping off, Phomopsis blight, bacterial wilt, Fusarium wilt, Verticillium wilt, Alternaria blight, and little leaf.
- These diseases can cause substantial yield losses and affect fruit quality.
- Understanding disease etiology and epidemiology is crucial for effective management.
Phomopsis Blight (Phomopsis vexans)
- Causal organism: Phomopsis vexans (syn. Diaporthe vexans).
- Symptoms include damping off in seedlings, leaf blight, and fruit rot.
- Leaf blight: Brown, round to oval spots with grey centers and dark margins; spots may coalesce and dry.
- Fruit rot: Pale sunken spots, black pycnidia on surface, mummification of fruit if infection is severe.
Phomopsis Blight: Etiology and Epidemiology
- Pycnidia are globose to irregular, brown to black, present in affected tissues.
- Conidiophores are hyaline, simple or branched; pycnidiospores are hyaline, one-celled, subcylindrical.
- Stylospores are filiform, curved, hyaline, and septate.
- Fungus survives in plant debris and is seed-borne; spreads via rain splash, implements, and insects.
- Wet weather and high temperatures (30–32°C) favor disease development.
Phomopsis Blight: Management
- Practice sanitation: collect and destroy diseased debris, rotate crops, and use disease-free seeds.
- Seed treatment with carbendazim (0.2%) or thiophanate methyl (0.2%) is recommended.
- Spray carbendazim (0.1%), mancozeb (0.25%), or copper oxychloride (0.3%) at 10–14 day intervals upon disease initiation.
Bacterial Wilt (Ralstonia solanacearum)
- One of the most devastating diseases in solanaceous crops, especially in warm, humid regions.
- Symptoms: Sudden wilting, drooping petioles, yellowing, stunting, and browning of vascular tissues.
- Milky bacterial ooze from cut stems; excessive adventitious root formation may occur.
Bacterial Wilt: Etiology and Epidemiology
- Causal agent: Ralstonia solanacearum, a gram-negative, motile, aerobic rod with polar flagella.
- Five races and four biovars exist; in India, races 1 and 3, biovars II, III, and IV are prevalent.
- Pathogen is soil- and seed-borne, survives in plant debris, tubers, wild hosts, and weeds for up to 2 years.
- Infection occurs through wounds in roots; high soil moisture and temperature favor disease.
Bacterial Wilt: Management
- No effective chemical control; all commercial cultivars are generally susceptible.
- Practice long crop rotation with non-solanaceous crops and avoid water movement from infected to healthy plants.
- Green manuring or biofumigation with Brassica spp. can reduce soil inoculum.
- Use bacterial antagonists (e.g., Pseudomonas fluorescens, Bacillus spp.) and soil solarization with dazomet.
- Seedling dip in Streptocycline (100 ppm, 30 min) and use of resistant cultivars are partially effective.
Verticillium Wilt (Verticillium dahliae)
- Symptoms: Yellowing and wilting of lower leaves, stunted growth, V-shaped lesions from leaf margins.
- Necrosis and browning of vascular tissues; lower leaves die and fall off, leading to plant death.
- Longitudinal brown streaks visible under stem tissue, especially at the plant base.
Verticillium Wilt: Host Range and Management
- Affects tomato, eggplant, potato, pepper, cabbage, cauliflower, cucumber, and pumpkin.
- Management includes selecting resistant varieties, crop rotation, and discarding infected material.
- Soil solarization, equipment sanitation, early-maturing varieties, weed control, and mulching with resistant tree material are recommended.
Fusarium Wilt (Fusarium oxysporum f.sp. lycopersici)
- Symptoms: Yellowing of lower leaves at flowering, premature leaf death, and browning of vascular bundles.
- One or more branches may be affected; cross-sections reveal vascular discoloration.
Fusarium Wilt: Etiology and Epidemiology
- Mycelium is septate, hyaline, becoming cream-colored; some isolates produce blue or red pigment.
- Microconidia are ellipsoidal, 1–2 celled; macroconidia are falcate, 3–5 septate, hyaline.
- Chlamydospores are thick-walled, terminal or intercalary, solitary or in chains.
- Pathogen is soil-borne, survives as mycelium and chlamydospores in debris and soil.
- Spread via water, contaminated equipment, and infected transplants; favored by hot, dry weather and acidic soils (pH 5.6–6.5).
Fusarium Wilt: Management
- Practice crop rotation with non-solanaceous crops and use healthy seed.
- Avoid water movement from infected to healthy plants.
- Apply combined inorganic fertilizers and organic manures; phosphate and nitrate fertilizers reduce incidence.
- Seed treatment with carbendazim (0.2%) and drenching with carbendazim/benomyl (0.1%) are effective.
- Use Pseudomonas isolates from rhizosphere to reduce infection.
Alternaria Leaf Spots (Alternaria spp.)
- Caused by Alternaria solani and Alternaria alternata f.sp. lycopersici.
- A. solani: Dark brown concentric ring spots (target board effect), coalescing into patches, leading to defoliation.
- A. alternata: Small, angular, light brown spots on leaves, stems, and branches; no yellow halo.
Alternaria Leaf Spots: Etiology and Epidemiology
- A. solani: Septate, branched, light brown hyphae; beaked, muriform conidia with multiple septa.
- A. alternata: Conidia are 1–5 septate, found on leaflet and stem lesions.
- Pathogen survives in plant debris and is seed-borne; primary infection via conidia from soil debris.
- Secondary spread by wind, water, and insects; optimal infection temperature is 25–30°C.
Alternaria Leaf Spots: Management
- Remove and destroy infected plant debris; practice at least two years of crop rotation.
- Use healthy seed and treat with captan (0.3%).
- Remove lower foliage (15–20 cm) in indeterminate varieties to reduce humidity.
- Spray chlorothalonil (0.2%) or mancozeb (0.25%) at 10–14 day intervals.
Objective Questions
Q1. Which of the following is the causal organism of Phomopsis blight in brinjal?
A. Phomopsis vexans (Diaporthe vexans)
B. Ralstonia solanacearum
C. Verticillium dahliae
D. Fusarium oxysporum f.sp. lycopersici
Answer: A
Q2. Which structure is characteristic of Phomopsis vexans in infected brinjal tissue?
A. Pycnidia
B. Sclerotia
C. Chlamydospores
D. Oospores
Answer: A
Q3. Which of the following management practices is NOT recommended for bacterial wilt of brinjal?
A. Application of carbendazim (0.2%)
B. Long crop rotation with non-solanaceous crops
C. Use of resistant cultivars/hybrids
D. Application of bleaching powder (15 kg/ha)
Answer: A
Q4. In Fusarium wilt of brinjal, which soil condition enhances disease severity?
A. Acidic soils (pH 5.6 to 6.5)
B. Alkaline soils (pH above 7.5)
C. Neutral soils (pH 7.0)
D. Calcareous soils
Answer: A
Q5. Which symptom is most characteristic of Alternaria solani infection in brinjal?
A. Dark brown spots with concentric rings (target board effect)
B. V-shaped lesions from leaf margin
C. Mummification of fruit
D. Milky bacterial ooze from stem
Answer: A
Q6. Which of the following is a distinguishing feature of Verticillium wilt in brinjal?
A. Longitudinal light brown to cream colored streaks under stem tissue
B. Pycnidia formation on fruit surface
C. Milky ooze from cross-sectioned stem
D. Target board effect on leaves
Answer: A
Q7. Which conidial characteristic is typical of Alternaria solani?
A. Beaked, muriform, dark, with 5-10 transverse septa and a few longitudinal septa
B. Filiform, curved, hyaline, and septate
C. Subcylindrical, one-celled, hyaline
D. Falcate, 3-5 septate, hyaline
Answer: A
Q8. Which of the following is NOT a recommended chemical for seed treatment against Phomopsis blight in brinjal?
A. Streptocycline
B. Carbendazim (0.2%)
C. Thiophenate methyl (0.2%)
D. Captan (0.3%)
Answer: A
Q9. Which environmental condition favors the development of bacterial wilt in brinjal?
A. High soil moisture and high soil temperature
B. Low soil moisture and low temperature
C. Acidic soils with low nitrogen
D. Cool, dry weather
Answer: A
Q10. Which of the following statements about Fusarium wilt management in brinjal is correct?
A. Application of ammonium fertilizers increases disease development
B. Application of nitrate fertilizers increases disease development
C. Monoculture reduces disease incidence
D. Hot dry weather suppresses wilt development
Answer: A
This presentation provides a comprehensive overview of the advanced production technology of walnut (Juglans regia L.), emphasizing its botanical characteristics, ecological requirements, and commercial significance. Key aspects include origin and distribution, propagation methods, orchard management, varietal improvement, and plant protection strategies. The content integrates recent research and best practices to enhance productivity and sustainability in walnut cultivation.
Introduction & Importance
- Walnut (Juglans regia L.) is a major temperate nut crop valued for its nutritional, economic, and ecological benefits.
- Known as the ‘royal nut,’ it has historical significance in trade and mythology, with origins traced to Persia (Iran) and spread to Europe and beyond.
- Walnut is a rich source of proteins, fats, minerals, and phytochemicals, notably omega-3 fatty acids, supporting brain health.
- All parts of the walnut tree are utilized: nuts for food, oil for culinary and industrial uses, timber for furniture, and shells for abrasives and insecticide diluents.
- Walnut cultivation contributes significantly to export earnings, especially in India, and is used for reclaiming degraded lands due to its robust root system.
Origin, Distribution & Systematics
- Walnut’s center of origin is Southeast Europe and Western Asia, with fossil evidence suggesting ancient cultivation.
- Major producers include China, Iran, USA, and Turkey; in India, Jammu & Kashmir leads production, followed by Himachal Pradesh and Uttarakhand.
- The genus Juglans (family Juglandaceae) comprises about 21 species, divided into sections such as Rhysocaryon (black walnuts) and Juglans (J. regia).
- Juglans regia is the primary commercial species, distinguished by hull dehiscence at maturity and high-quality nuts.
- Other species like J. nigra (Eastern black walnut) and J. hindsii (Northern California black walnut) are important for rootstocks and timber.
Botanical Description
- Walnut is a large, deciduous tree with aromatic, pinnately compound leaves and chambered pith in shoots.
- Monoecious flowering habit: male (staminate) flowers in catkins on previous season’s growth; female (pistillate) flowers at shoot tips.
- Fruit is a true nut (drupaceous nut), with an edible portion being the lobed cotyledons inside a hard shell and involucre (husk).
- Exhibits allelopathic effects, suppressing weed growth beneath the canopy.
- Growth follows a double sigmoid curve, with two rapid periods of fruit development interspersed by slower growth.
Ecological Requirements
- Optimal altitude for commercial cultivation: 900–2500 m above sea level; superior nut quality at higher elevations but risk of frost above 2500 m.
- Requires cool autumns for dormancy induction; tolerates -11°C in dormancy but is sensitive to late spring and early fall frosts.
- Chilling requirement varies by cultivar (700–1500 hours below 7°C).
- Prefers deep, well-drained, slightly acidic soils (pH 5.5–6.5) rich in organic matter; intolerant of waterlogging.
- Annual rainfall or irrigation equivalent of 760–800 mm is necessary; shelter from strong winds is recommended.
Commercial Varieties
- Major Indian varieties: CITH Walnut-1 to 10, Hamdan, Sulaiman, and selections like Govind and Roopa; international cultivars include Chandler, Hartley, Franquette, and Serr.
- Varietal traits include nut size, shell thickness, kernel color, yield, and bearing habit (terminal vs. lateral).
- Lateral bearing trait is associated with early and higher yields; CITH-W-121 is a notable Indian accession with this trait.
- Interspecific hybrids (e.g., Paradox: J. hindsii × J. regia) are used as rootstocks for disease resistance and adaptability.
- Selection of varieties with desirable traits (precocity, nut quality, disease resistance) is crucial for productivity improvement.
Propagation
- Walnut is propagated by seeds (for rootstocks) and vegetative methods (grafting, budding) for true-to-type plants.
- Common rootstocks: J. regia (Asia), J. hindsii, J. nigra, and Paradox hybrid (USA); choice depends on soil and disease resistance.
- Vegetative propagation methods include cleft grafting, patch budding, and epicotyl grafting; success rates are improved under controlled humidity and temperature.
- Recent advances: Epicotyl grafting with dwarf rootstocks and sawdust covering yields high success; omega and V-grafting methods enhance callusing and survival.
- Micropropagation and hot water callusing techniques are being explored for mass propagation.
Planting & Layout
- Recommended planting systems: square or quincunx, with pollinizer varieties every 8th row perpendicular to wind direction.
- Spacing varies by rootstock: 12×12 m (seedlings), 10×10 m (J. regia grafted), 8×8 m (J. nigra grafted).
- Pits are prepared based on soil type and filled with a mixture of farmyard manure and topsoil.
- High-density planting (closer spacing) increases early yield and net returns, though dwarfing rootstocks are not yet widely used.
- Planting is done in late dormant or early spring, followed by immediate irrigation.
Tree Architecture & Pruning
- Walnut trees are trained to a modified central leader system with 5–6 main laterals.
- Pruning is conducted in early spring to avoid excessive bleeding; selective thinning prevents overcrowding.
- Bearing habit (terminal vs. lateral) influences tree structure and productivity; lateral bearing is linked to higher yields and precocity.
- Cluster bearing genotypes (e.g., SN-1) have been identified, offering potential for increased productivity.
- Peaches are sometimes interplanted for the first 10–15 years to utilize space and resources efficiently.
Flowering Physiology
- Walnut is monoecious and dichogamous, with male and female flowers maturing at different times to promote cross-pollination.
- Flowering period varies by cultivar and location; peak in mid-April to early May in northern India.
- Pollen viability is low and stigma receptivity is brief, necessitating overlapping bloom periods or mixed cultivar planting for effective pollination.
- Application of gibberellic acid (GA₃) can alter flowering patterns and increase flower numbers, especially in larger trees.
- Pollen can be collected and stored at sub-zero temperatures to extend viability for artificial pollination.
Orchard Cultural Practices
- Fertilizer application is based on tree age and leaf nutrient analysis; split applications of nitrogen are recommended for optimal uptake.
- Intercropping with legumes and low-growing vegetables is feasible during the early years of orchard establishment.
- Irrigation is essential during dry periods and critical growth stages, but overwatering should be avoided to prevent root diseases.
- Weed control is achieved using herbicides like simazine and diuron, along with mulching to conserve moisture and suppress weeds.
- Mulching is particularly important for young trees and after fertilizer application in mature orchards.
Harvesting & Handling of Fruit
- Harvest when 80% of hulls have split and packing tissue turns brown (PTB stage); delay reduces nut quality and increases disease risk.
- Harvesting involves manual collection or branch shaking, with multiple pickings over several weeks.
- Post-harvest handling includes cleaning, washing, and drying nuts to 8% moisture to prevent mold and rancidity.
- Grading is based on nut size and color; lighter kernels fetch higher market prices.
- Proper storage at low temperature and humidity extends shelf life and maintains quality.
Walnut Plant Protection
- Major diseases: walnut anthracnose (Gnomonia leptostyla), walnut blight (Xanthomonas campestris pv. juglandis), black line disease (cherry leaf roll virus), foot and root rot, and powdery mildew.
- Integrated management includes sanitation, resistant varieties/rootstocks, chemical sprays (e.g., Bordeaux mixture, copper, carbendazim), and proper drainage.
- Key insect pests: walnut leaf gall mite (Aceria arinoea), walnut aphid (Chromaphis juglandicola), codling moth (Cydia pomonella), walnut weevil (Alicides porrectirostis), and husk fly (Rhagoletis completa).
- Pest control strategies involve timely insecticide applications, pheromone traps, and destruction of infested fruits.
- Reducing tree size through grafted trees, dwarfing rootstocks, and pruning facilitates pest management and harvesting.
Future Thrusts
- Challenges include low productivity due to poor planting material, pollination issues, low tree density, long juvenile period, and susceptibility to pests and diseases.
- Breeding and selection for lateral bearing, short stature, early bearing, improved nut quality, and disease resistance are priorities.
- Adoption of advanced propagation techniques and high-density planting can enhance orchard profitability.
- Integrated pest and disease management, along with climate-resilient practices, are essential for sustainable walnut production.
- Continued research and extension support are needed to address emerging challenges and promote best practices among growers.
Objective Questions
Q1. Which walnut species is most commonly used as a rootstock in Asia due to its compatibility and resistance to crown rot disease?
A. Juglans regia
B. Juglans hindsii
C. Juglans nigra
D. Juglans microcarpa
Answer: A
Q2. Which method of walnut grafting resulted in the highest callused grafts and graft-take percentages according to Majd et al. (2018)?
A. Tongue grafting
B. Omega grafting
C. Saddle grafting
D. V grafting
Answer: B
Q3. What is the chromosome number of Juglans regia?
A. 2n = 28
B. 2n = 32
C. 2n = 24
D. 2n = 36
Answer: B
Q4. Which state in India contributes more than 85% of the total walnut production in the country?
A. Himachal Pradesh
B. Uttarakhand
C. Jammu & Kashmir
D. Arunachal Pradesh
Answer: C
Q5. Which walnut rootstock is most tolerant to salts in soil or irrigation and resistant to oak root fungus in California?
A. Juglans regia
B. Juglans nigra
C. Juglans hindsii
D. Juglans microcarpa
Answer: C
Q6. Which of the following is a classical example of delayed incompatibility in walnut, caused by a virus and characterized by a dark line between stock and scion?
A. Walnut blight
B. Black line formation
C. Foot and root rot
D. Powdery mildew
Answer: B
Q7. In walnut, which type of dichogamy is exhibited by the English walnut (Juglans regia)?
A. Protogyny only
B. Both protogyny and protoandry
C. Protoandry only
D. None of the above
Answer: C
Q8. According to the research by Chand et al. (2018), which accession was identified as the first indigenous Indian walnut with lateral bearing trait?
A. CITH Walnut-1
B. CITH-W-121 (IC-0622836)
C. Sulaiman
D. Hamdan
Answer: B
Q9. For maximum propagation efficiency in walnut epicotyl grafting, which combination is recommended based on Raufi et al. (2017)?
A. Standard rootstock + perlite cover
B. Dwarf rootstock + sawdust cover
C. Standard rootstock + coco-peat cover
D. Dwarf rootstock + polyethylene cover
Answer: B
Q10. Which disease of walnut is caused by Xanthomonas campestris pv. juglandis and is best controlled by spraying metallic copper?
A. Walnut anthracnose
B. Walnut blight
C. Powdery mildew
D. Foot and root rot
Answer: B
Mango, a major tropical fruit crop, is susceptible to a range of fungal, bacterial, and algal diseases that can significantly impact yield and fruit quality. Understanding the symptoms, causal organisms, and management strategies for these diseases is essential for sustainable mango production. This presentation provides an overview of the most important mango diseases, their identification, and integrated management approaches.
Major Diseases of Mango
- Anthracnose (Colletotrichum gloeosporioides)
- Powdery mildew (Oidium mangiferae)
- Mango malformation (Fusarium moniliforme var. subglutinans)
- Stem end rot (Botryodiplodia theobromae)
- Red rust (Cephaleuros virescens)
- Grey blight (Pestalotia mangiferae)
- Sooty mould (Capnodium mangiferae)
Anthracnose: Symptoms and Causal Organism
- Caused by Colletotrichum gloeosporioides, a widespread fungal pathogen.
- Symptoms include leaf spots, blossom blight, wither tip, twig blight, and fruit rot.
- Small, blister-like spots develop on leaves and twigs; young leaves wither and dry.
- Fruits show black spots; pulp hardens, cracks, and decays at ripening, leading to fruit drop.
- Severe infections cause dieback of branches and significant yield loss.
Anthracnose: Management
- Spray Pseudomonas fluorescens (FP 7) at 3-week intervals from October at 5 g/liter on flower branches.
- Apply 5–7 sprays, including applications on flowers and fruit bunches.
- Pre-storage treatment: hot water (50–55°C) for 15 minutes or dip in Benomyl (500 ppm) or Thiobendazole (1000 ppm) for 5 minutes.
- Practice field sanitation and remove infected plant debris to reduce inoculum.
Powdery Mildew: Symptoms and Causal Organism
- Caused by Oidium mangiferae (syn. Acrosporium mangiferae).
- Affects leaves, flowers, panicle stalks, and young fruits.
- White powdery growth appears on affected parts; severe infection leads to leaf shedding.
- Infected fruits fail to develop and may drop at pea size.
- Pathogen survives as dormant mycelium in leaves; spreads by airborne conidia.
Powdery Mildew: Management
- Dust plants with fine sulphur (250–300 mesh) at 0.5 kg/tree.
- First application after flowering, second after 15 days.
- Alternatively, spray wettable sulphur (0.2%), Carbendazim (0.1%), Tridemorph (0.1%), or Karathane (0.1%).
- Ensure good air circulation and avoid excessive irrigation to reduce humidity.
Mango Malformation: Symptoms and Causal Organism
- Caused by Fusarium moniliforme var. subglutinans.
- Three symptom types: bunchy top phase, floral malformation, and vegetative malformation.
- Bunchy top: thickened, stunted shoots with rudimentary leaves in nursery plants.
- Vegetative malformation: excessive, swollen branches with short internodes, forming bunches.
- Floral malformation: abnormal panicles, dried malformed heads persisting on trees; witches’ broom appearance.
Mango Malformation: Management
- Destroy diseased plants and use disease-free planting material.
- Spray 100–200 ppm NAA (naphthalene acetic acid) during October to reduce incidence.
- Prune diseased parts along with 15–20 cm of healthy tissue.
- Follow up with Carbendazim (0.1%) or Captafol (0.2%) sprays.
Stem End Rot: Symptoms and Causal Organism
- Primarily caused by Botryodiplodia theobromae (syn. Diplodia natalensis).
- Initial symptom: darkening of epicarp around fruit pedicel, forming a circular black patch.
- Under humid conditions, infection spreads rapidly, turning the whole fruit black within days.
- Pulp becomes brown and soft; disease often spreads from dead twigs and bark, especially during rains.
Stem End Rot: Management
- Prune and destroy infected twigs to reduce inoculum.
- Spray Carbendazim or Thiophanate-methyl (0.1%) or Chlorothalonil (0.2%) at fortnightly intervals during rainy season.
- Maintain orchard hygiene and avoid injuries to fruits during harvest.
Red Rust: Symptoms and Causal Organism
- Caused by the algal pathogen Cephaleuros virescens.
- Rusty, circular, slightly elevated spots appear on leaves and young twigs.
- Spots may coalesce to form irregular lesions; mature spores fall off, leaving a cream to white velvety texture.
- Reduces photosynthetic area and weakens affected branches.
Red Rust: Management
- Spray Bordeaux mixture (0.6%) or copper oxychloride (0.25%) on affected trees.
- Remove and destroy heavily infected plant parts to limit spread.
Grey Blight: Symptoms and Causal Organism
- Caused by Pestalotia mangiferae.
- Brown spots develop on leaf margins and tips, enlarging and turning dark brown.
- Black acervuli (fruiting bodies) appear on spots; fungus survives on leaves for over a year.
- Spread by wind-borne conidia; severe during monsoon with 20–25°C temperature and high humidity.
Grey Blight: Management
- Remove and destroy infected plant parts to reduce inoculum.
- Spray copper oxychloride (0.25%), Mancozeb (0.25%), or Bordeaux mixture (1.0%).
Sooty Mould: Symptoms and Causal Organism
- Caused by Capnodium mangiferae, a saprophytic fungus.
- Superficial black mycelial growth develops on leaves, stems, and fruits.
- Fungus grows on honeydew secreted by sap-sucking insects (jassids, aphids, scale insects).
- Black encrustation reduces photosynthetic activity and fruit quality.
Sooty Mould: Management
- Simultaneously manage sap-sucking insects and sooty mould.
- Spray systemic insecticides such as Monocrotophos or methyl demeton to control insect vectors.
- Apply starch solution (1 kg starch/maida in 5 liters water, boiled and diluted to 20 liters) to affected parts; dried starch flakes remove fungus.
Objective Questions
Q1. Which pathogen is responsible for causing anthracnose in mango?
A. Colletotrichum gloeosporioides
B. Oidium mangiferae
C. Fusarium moniliforme var. subglutinans
D. Botrydiplodia theobromae
Answer: A
Q2. Which of the following is NOT a symptom of mango malformation caused by Fusarium moniliforme var. subglutinans?
A. Bunchy top phase in nursery
B. Black encrustation on leaves
C. Floral malformation
D. Vegetative malformation
Answer: B
Q3. Which management practice is recommended for controlling powdery mildew in mango?
A. Dusting fine sulphur at 0.5 kg/tree
B. Spraying Bordeaux mixture 1.0%
C. Treating fruits with hot water at 50-55°C
D. Spraying Monocrotophos
Answer: A
Q4. Which disease of mango is characterized by the formation of black encrustation on leaves due to fungal growth on sugary secretions?
A. Sooty mould
B. Grey blight
C. Red rust
D. Anthracnose
Answer: A
Q5. Which chemical is NOT recommended for the management of mango anthracnose before storage?
A. Benomyl (500 ppm)
B. Thiobendazole (1000 ppm)
C. Wettable sulphur (0.2%)
D. Hot water treatment at 50-55°C
Answer: C
Q6. The causal organism of stem end rot in mango is:
A. Diplodia natalensis
B. Cephaleuros mycoides
C. Pestalotia mangiferae
D. Capnodium mangiferae
Answer: A
Q7. Which symptom is specifically associated with red rust of mango?
A. Rusty, circular, slightly elevated spots on leaves
B. Brown spots with black acervuli on leaf margins
C. Black spots on fruit with hardening of pulp
D. Black encrustation affecting photosynthesis
Answer: A
Q8. Which of the following is a recommended management strategy for grey blight in mango?
A. Spraying copper oxychloride 0.25%
B. Dusting with fine sulphur
C. Spraying systemic insecticides
D. Dipping fruits in Benomyl solution
Answer: A
Q9. What is the primary mode of secondary spread for powdery mildew in mango?
A. Air borne conidia
B. Rain splash
C. Insect vectors
D. Soil-borne sclerotia
Answer: A
Q10. Which of the following is NOT a recommended management practice for sooty mould in mango?
A. Spraying systemic insecticides for insect control
B. Spraying starch solution to remove fungus
C. Spraying Bordeaux mixture 1.0%
D. Removing flakes formed by dried starch
Answer: C
Sapota (Manilkara achras), commonly known as sapodilla or chiku, is a tropical fruit crop of the family Sapotaceae. It is valued for its nutritional and economic significance, thriving in diverse agro-climatic conditions and marginal lands. Effective management of soil, climate, nutrients, and water, along with addressing specific problems, is essential for optimizing sapota cultivation and yield.
Introduction and Importance
- Sapota (Manilkara achras) is a tropical fruit introduced from Central America, widely cultivated in India.
- Commonly known as sapodilla or chiku, it belongs to the family Sapotaceae.
- Fruits are recommended for patients with tuberculosis and children with primary complex due to their nutritional value.
- Offers high economic returns, even under marginal land and low-input conditions.
Climate and Soil Requirements
- Grows well from sea level up to 1200 m altitude, preferring warm, moist climates.
- Optimal temperature range: 11°C to 34°C; annual rainfall: 1250–2500 mm.
- Best suited to coastal climates but adaptable to both dry and humid regions.
- Prefers deep, well-drained, porous soils such as alluvium, sandy loams, red laterites, and medium black soils.
- Tolerates moderate soil and irrigation water salinity.
Propagation and Planting
- Propagation is mainly through grafting onto Manilkara hexandra (Pala) rootstock.
- Planting season: June to December; recommended spacing: 8 x 8 m (standard), 8 x 4 m (high density).
- Pits of 1 m³ are prepared and filled with topsoil, 10 kg FYM, 1 kg neem cake, and 100 g lindane (1.3%).
- Grafts are planted with the graft union at least 15 cm above ground and staked for support.
Nutrient and Water Management
- Immediate and regular irrigation is crucial after planting; water copiously post-planting, then every 10 days until establishment.
- Annual application of FYM and NPK fertilizers, increasing with tree age; mature trees (6th year onwards) require 50 kg FYM, 1 kg N, 1 kg P, and 1.5 kg K per tree.
- Fertilizers should be applied in September–October, 45 cm from the trunk, and incorporated into the soil up to the leaf drip line.
Aftercare and Intercropping
- Regular removal of rootstock sprouts, water shoots, criss-cross, and lower branches is essential for healthy growth.
- Legumes and short-duration vegetable crops can be intercropped during the pre-bearing stage to improve soil fertility and income.
Plant Protection and Disease Management
- Leaf webber: Controlled by spraying phosalone at 2 ml/liter.
- Hairy caterpillars: Managed with endosulfan at 2 ml/liter (note: endosulfan use is restricted in many countries; safer alternatives are recommended).
- Budworm: Controlled by phosalone spray at 2 ml/liter.
- Sooty mould: Treated by spraying a 5% solution of boiled maida or starch (1 kg in 20 liters water).
Harvesting, Ripening, and Yield
- Fruits are ready for harvest when dull brown and the skin beneath is lighter in color; mature fruits lose brown scaly material and have reduced latex.
- Harvesting is done by hand picking; main seasons are February–June and September–October.
- Ripening is accelerated by placing fruits in airtight chambers with 5000 ppm Ethrel and 10 g NaOH pellets.
- Yield starts from the third year, reaching 20–25 t/ha/year in mature orchards.
Objective Questions
Q1. What is the ideal annual rainfall range for optimal sapota cultivation?
A. 500-1000 mm
B. 1250-2500 mm
C. 3000-4000 mm
D. 100-500 mm
Answer: B
Q2. Which rootstock is commonly used for grafting sapota plants?
A. Manilkhara zapota
B. Manilkhara hexandra
C. Achras sapota
D. Pouteria campechiana
Answer: B
Q3. What is the recommended spacing for high density planting of sapota?
A. 10 x 10 m
B. 6 x 6 m
C. 8 x 4 m
D. 12 x 12 m
Answer: C
Q4. Which of the following soils is NOT considered ideal for sapota cultivation?
A. Deep alluvium
B. Sandy loam
C. Red laterite
D. Heavy clay with hard pan
Answer: D
Q5. At what minimum height above ground should the graft joint be positioned when planting sapota?
A. 5 cm
B. 10 cm
C. 15 cm
D. 25 cm
Answer: C
Q6. Which chemical is recommended for spraying against sapota leaf webber?
A. Endosulfan
B. Phosalone
C. Lindane
D. Ethrel
Answer: B
Q7. What is the total amount of FYM (Farm Yard Manure) recommended per tree for a 6-year-old sapota?
A. 10 kg
B. 20 kg
C. 30 kg
D. 50 kg
Answer: D
Q8. Which intercrops are suitable during the pre-bearing stage of sapota?
A. Cereals and oilseeds
B. Legumes and short duration vegetables
C. Tubers and spices
D. Plantation crops
Answer: B
Q9. What is the recommended method for ripening harvested sapota fruits?
A. Exposing to sunlight
B. Dipping in ethylene solution
C. Keeping in airtight chamber with 5000 ppm Ethrel + 10 g NaOH pellets
D. Spraying with gibberellic acid
Answer: C
Q10. Which of the following is a clear sign of sapota fruit maturity?
A. Fruit turns bright green
B. Brown scaly materials disappear from the surface
C. Milky latex content increases
D. Stigma becomes sticky
Answer: B
This lecture provides a comprehensive overview of Papaya (Carica papaya L.), focusing on its soil and climate requirements, water and nutrient management, propagation, and the extraction and uses of papain. Emphasis is placed on cultivation practices, pest and disease management, and the economic significance of papaya in tropical and subtropical agriculture. The lecture also addresses the physiological and reproductive biology of papaya, highlighting its importance in sustainable horticultural production.
Introduction and Economic Importance
- Papaya (Carica papaya L.) belongs to the family Caricaceae and has a chromosome number of 2n=18.
- Native to Tropical America, papaya was introduced to India in the 18th century and is now widely cultivated in tropical and subtropical regions.
- Major producing states in India include Bihar, Assam, Maharashtra, Madhya Pradesh, and Andhra Pradesh, with a cultivation area of approximately 34,000 ha.
- Papaya is valued for its high vitamin A content (2000 IU/100g) and is consumed fresh or processed into products like jam, jelly, and nectar.
- The fruit is a significant source of the proteolytic enzyme papain, which has diverse applications in medicine and industry.
Botanical Characteristics and Sex Expression
- Papaya plants exhibit dioecious, hermaphrodite, and gynodioecious sex forms, influencing fruit set and orchard management.
- Dioecious types have separate male and female plants, while hermaphrodite and gynodioecious types bear both flower types on the same plant.
- Male flowers are borne on long panicles; female flowers are solitary and larger, with a prominent ovary.
- Fruit morphology varies: globular from female flowers and elongated from bisexual flowers.
- Sex expression is influenced by environmental factors (temperature, day length) and growth regulators (e.g., GA, ethrel, SADH, phosphon-D).
Soil and Climate Requirements
- Papaya thrives best in deep, well-drained loamy soils with uniform texture up to 1.8 m depth.
- Good drainage is essential; even brief water stagnation can cause collar-rot disease.
- Optimal temperature range is 35–38°C; papaya is sensitive to frost and extreme heat.
- Windbreaks are recommended in areas prone to strong winds to prevent tree damage.
- Regions with mild temperatures and low incidence of viral diseases, such as Tamil Nadu, are ideal for year-round cultivation.
Propagation and Planting
- Papaya is primarily propagated by seeds, which are collected from mature, healthy fruits and cleaned before sowing.
- Seedlings are raised in nursery beds or polythene bags; the latter method produces more vigorous plants.
- For dioecious varieties, 2–3 seedlings per pit are planted to ensure sufficient female plants; excess males are removed after sex identification.
- Planting is done in pits of 45 x 45 x 45 cm at 1.8 x 1.8 m spacing, accommodating about 3000 plants/ha.
- The best planting time coincides with the onset of the South-West monsoon or during mild weather periods.
Nutrient and Water Management
- Papaya requires regular and balanced fertilization due to its rapid growth and continuous fruiting habit.
- Recommended nutrient application includes 10 kg FYM/plant as basal and 50 g each of N, P, and K per plant bimonthly, or 250 g N, 250 g P2O5, and 500 g K2O per plant/year in split doses.
- Peak nutrient uptake occurs between flowering and harvesting stages.
- Regular irrigation is essential, typically every 8–10 days, but waterlogging must be avoided to prevent root diseases.
- Intercropping with short-duration vegetables is possible during the pre-bearing stage.
Harvesting, Yield, and Post-Harvest Handling
- Fruits mature 12–14 months after planting, with continuous cropping possible for up to 2 years.
- Harvesting is done when fruits change from green to yellowish-green, using careful hand picking to avoid damage.
- Average yield per tree ranges from 50 to 100 fruits; high-yielding varieties can produce 100–160 t/ha.
- Fruits for local markets are stored in straw layers; for distant transport, they are packed in straw-lined bamboo baskets.
- Yield and fruit quality depend on the proportion of female and hermaphrodite trees in the orchard.
Papain Extraction and Uses
- Papain is a proteolytic enzyme extracted from the latex of unripe, fully developed green papaya fruits.
- Latex is collected by making shallow incisions on the fruit surface, preferably using non-metallic tools to prevent discoloration.
- Collected latex is sun-dried or artificially dried at 50–55°C, then powdered and stored in airtight containers.
- Papain is used in medicine (digestive aid, ulcer treatment), food industry (meat tenderizer, beer clarification), textiles, cosmetics, and other industrial applications.
- Factors affecting papain yield include fruit size, maturity, and varietal characteristics; potassium metabisulphite may be added to improve quality and shelf life.
Pest and Disease Management
- Papaya is susceptible to several diseases, notably collar-rot, mosaic virus, and leaf curl virus, especially in poorly drained or virus-prone areas.
- Good field sanitation, use of disease-free seeds, and resistant varieties are key preventive measures.
- Regular weeding and removal of infected plants help reduce disease incidence.
- Common pests include fruit flies, aphids, and red spider mites; integrated pest management strategies are recommended.
- Windbreaks and proper irrigation management also contribute to reducing pest and disease pressure.
Objective Questions
Q1. Which of the following statements about papaya sex expression is correct?
A. Gynodioecious papaya plants bear both female and bisexual flowers on the same plant.
B. Dioecious papaya plants have both male and female flowers on the same plant.
C. Hermaphrodite papaya plants never produce male flowers.
D. All papaya plants are monoecious by nature.
Answer: A
Q2. What is the recommended fertilizer dose per plant per year for higher yield in papaya according to the Indian Institute of Horticulture Research, Bangalore?
A. 250 g N, 250 g P2O5, 500 g K2O in six split applications
B. 100 g N, 100 g P2O5, 200 g K2O in two split applications
C. 50 g N, 50 g P2O5, 100 g K2O in one application
D. 500 g N, 500 g P2O5, 1000 g K2O in twelve split applications
Answer: A
Q3. Which of the following is NOT a recommended use of papain extracted from papaya?
A. Clarifying beer
B. Tenderizing meat
C. Increasing fruit sweetness
D. Pre-shrinking wool
Answer: C
Q4. What is the main reason for providing wind breaks in papaya cultivation?
A. To prevent wind damage to trees
B. To increase soil fertility
C. To enhance fruit sweetness
D. To control pest infestation
Answer: A
Q5. Which of the following factors does NOT influence sex expression in papaya?
A. Growth regulators like GA and ethrel
B. Season of planting
C. Soil drainage
D. Environmental temperature
Answer: C
Q6. What is the preferred method of propagation for papaya and why?
A. By seeds, because vegetative methods are not economical
B. By cuttings, because it ensures true-to-type plants
C. By grafting, because it increases fruit size
D. By tissue culture, because it is faster
Answer: A
Q7. During papain extraction, why are non-metallic instruments preferred for tapping and collecting latex?
A. To prevent discoloration of the latex
B. To increase latex yield
C. To avoid contamination with soil
D. To reduce labor cost
Answer: A
Q8. Which papaya species is known as 'mountain papaya' and thrives at elevations between 1500 to 2000m in the Western Ghats?
A. Carica candamarcensis
B. Carica monica
C. Carica papaya
D. Carica pubescens
Answer: A
Q9. What is the main consequence of failing to use controlled pollination (sib mating) in papaya seed production?
A. Deterioration of variety and mixed progeny types
B. Increased fruit size
C. Higher papain content
D. Reduced need for irrigation
Answer: A
Q10. According to TNAU recommendations, what is the basal application of farmyard manure (FYM) per papaya plant?
A. 10 kg per plant
B. 1 kg per plant
C. 25 kg per plant
D. 50 kg per plant
Answer: A
This presentation provides an in-depth overview of major diseases affecting brinjal (eggplant), focusing on their pathogens, symptoms, epidemiology, and management strategies. Emphasis is placed on the biology of the causal agents, disease cycles, and integrated approaches for effective control. Understanding these aspects is crucial for sustainable brinjal production and minimizing crop losses.
Little Leaf Disease of Brinjal
- Caused by Phytoplasma, an ovoid to spherical pathogen localized in phloem sieve tubes.
- Characterized by small, yellow, soft leaves with shortened petioles and internodes, giving a bushy appearance.
- Axillary buds enlarge but remain stunted; flowering is rare and flowers, if present, remain green.
- Fruiting is uncommon; any formed fruits are hard, necrotic, and often mummified.
- Pathogen survives in weed hosts and is transmitted mainly by jassids (Hishimonas phycitis) and less efficiently by Empoasca devastans.
Epidemiology and Management of Little Leaf Disease
- Collateral hosts include Datura spp., Vinca rosea, Argemone mexicana, chilli, tomato, and tobacco.
- Disease cycle involves survival in weed hosts and transmission by insect vectors.
- Management includes use of tolerant varieties (Pusa Purple Round, Pusa Purple Cluster, Arka Sheel).
- Destruction of infected plants and eradication of solanaceous weeds are essential.
- Chemical control: Spray methyl demeton (2 ml/L) or apply phorate granules; seed dip in tetracycline (10–50 ppm) recommended.
Bacterial Wilt of Brinjal
- Caused by Ralstonia solanacearum, a Gram-negative, motile rod with polar flagella.
- Race 1 infects solanaceous crops (tomato, eggplant) and some non-solanaceous hosts.
- Symptoms include sudden wilting, leaf epinasty, yellowing, stunting, and browning of vascular tissues.
- Whitish bacterial exudate may be observed from cross-sections of infected stems.
Epidemiology and Management of Bacterial Wilt
- Pathogen is both soil- and seed-borne, surviving in plant debris, wild hosts, and weeds.
- Spread occurs via irrigation water, infested soil, and contaminated tools.
- Favored by high soil moisture and temperature.
- Management: Grow resistant varieties (Pant Samrat, Arka Nidhi, Arka Neelakantha, Surya, BB 1, 44, 49).
- Practices include crop rotation with non-solanaceous crops, green manuring (Brassica spp.), soil solarization, and biological control (Pseudomonas fluorescens, Bacillus spp., Erwinia spp.).
Integrated Management of Bacterial Wilt
- Nursery: Treat seeds with talc-based Pseudomonas fluorescens (10g/100g seed); apply to nursery soil (50g/kg soil).
- Main field: Dip seedlings in P. fluorescens or Bacillus subtilis suspension (25g talc formulation/L water) for 20–30 minutes before transplanting.
- Drench leftover solution around root zones (50 ml/plant) to enhance protection.
Phomopsis Fruit Rot (Blight) of Brinjal
- Severe in tropical and subtropical regions; first reported in India (Gujarat, 1935).
- Pathogen produces septate, hyaline mycelium; pycnidia become erumpent with age.
- Conidia are of two types: alpha (subcylindrical) and beta (filiform, curved); perfect stage forms perithecia with bicelled ascospores.
- Attacks all growth stages, causing damping-off in nurseries, collar rot in young plants, and fruit rot in mature plants.
Symptoms and Epidemiology of Phomopsis Fruit Rot
- Leaf symptoms: Circular to irregular grayish-brown spots with light centers; yellowing and premature leaf drop.
- Stem lesions: Dark brown, oval, with grayish centers and pycnidia; can cause cankers and plant toppling.
- Fruit symptoms: Pale, sunken spots that enlarge and become watery, leading to soft rot and mummification.
- Pathogen is seed-borne and survives in plant debris as mycelium and pycnidia.
- Dissemination via rain splash, irrigation, tools, and insects.
Management of Phomopsis Fruit Rot
- Remove and destroy diseased crop debris to reduce inoculum.
- Practice crop rotation and summer ploughing to minimize pathogen survival.
- Use disease-free seed; hot water treat seed at 50°C for 30 minutes.
- Seed treatment with thiophanate methyl (1g/kg seed) recommended.
- Spray thiophanate methyl or carbendazim (0.1%) twice at 20-day intervals for effective control.
Cercospora Leaf Spot of Brinjal
- Caused by Cercospora spp., leading to significant yield losses under high humidity.
- Symptoms: Large, circular to irregular brown or grayish-brown leaf spots; coalescence leads to premature leaf drop and occasional fruit rot.
- Fungus survives in infected plant debris and seeds; warm days, cool nights, and high humidity favor disease development.
- Transmission facilitated by moist wind, irrigation water, and insects.
Management of Cercospora Leaf Spot
- Adopt cultural practices: Destroy crop debris, rotate crops, use disease-free seeds, and maintain wider plant spacing.
- Initiate fungicidal sprays (zineb 0.25%, carbendazim 0.1%, or thiophanate methyl 0.1%) at disease onset.
- Repeat sprays at 10–14 day intervals for sustained protection.
Objective Questions
Q1. Which pathogen is responsible for little leaf disease in brinjal?
A. Phytoplasma
B. Ralstonia solanacearum
C. Cercospora melongenae
D. Phomopsis vexans
Answer: A
Q2. Which vector is considered a less efficient transmitter of little leaf disease in brinjal?
A. Hishimonas phycitis
B. Emposca devastans
C. Bemisia tabaci
D. Myzus persicae
Answer: B
Q3. Which management practice is NOT recommended for bacterial wilt of brinjal?
A. Use of resistant varieties like Pant Samrat and Arka Nidhi
B. Green manuring with Brassica species
C. Spraying methyl demeton
D. Soil solarization with transparent polyethylene sheet
Answer: C
Q4. What is the main symptom of Phomopsis fruit rot on brinjal fruits?
A. Small pale sunken spots that enlarge and cover the fruit surface
B. Water-soaked lesions with concentric rings
C. Powdery white growth on fruit surface
D. Black streaks along the fruit
Answer: A
Q5. Which of the following is NOT a collateral host for little leaf phytoplasma in brinjal?
A. Datura fastuosa
B. Vinca rosea
C. Brassica juncea
D. Argemone mexicana
Answer: C
Q6. Which of the following is a recommended seed treatment for managing Phomopsis fruit rot in brinjal?
A. Tetracycline 10-50 ppm
B. Hot water at 50°C for 30 minutes
C. Carbendazim 0.5% for 10 minutes
D. Copper oxychloride 0.2%
Answer: B
Q7. Which environmental condition most favors the development of Cercospora leaf spot in brinjal?
A. High humidity and heavy persistent dews
B. Low temperature and dry weather
C. High soil salinity
D. Alkaline soil pH
Answer: A
Q8. Which symptom is characteristic of bacterial wilt in brinjal?
A. Sudden wilting and death of infected plants
B. Mosaic pattern on leaves
C. Leaf curling and stunting
D. Brown pustules on stems
Answer: A
Q9. Which of the following is NOT a management strategy for little leaf disease in brinjal?
A. Destruction of affected plants
B. Eradication of solanaceous weed hosts
C. Crop rotation with solanaceous crops
D. Seed dip in tetracycline
Answer: C
Q10. Which type of conidia produced by Phomopsis fruit rot pathogen has an unclear role in disease epidemiology?
A. Alpha conidia
B. Beta conidia
C. Gamma conidia
D. Delta conidia
Answer: B
This presentation provides an in-depth overview of the major insect pests affecting okra and other vegetable crops, focusing on their identification, life cycle, damage symptoms, and management strategies. Emphasis is placed on integrated pest management (IPM) approaches, highlighting the importance of biological, cultural, and chemical control methods for sustainable crop protection.
Okra Shoot and Fruit Borer (Earias spp.) – Identification and Biology
- Key species: Earias vitella and Earias insulana (Family: Noctuidae; Order: Lepidoptera).
- E. vitella adults have pale whitish forewings with a broad greenish band; E. insulana adults have uniformly green forewings.
- Larvae are brown with dorsal white streaks; pupae are brown and boat-shaped.
- Eggs are laid on tender shoots, flower buds, and young fruits; each female lays up to 250 eggs.
- Life cycle duration: 3 weeks in summer, 4 weeks in winter; up to 12 generations per year.
Economic Importance and Nature of Damage – Okra Shoot and Fruit Borer
- Serious pest of okra, cotton, ambadi, and other malvaceous plants.
- Larvae bore into tender shoots, flower buds, and fruits, causing withering and drying of shoots.
- Infested flower buds and fruits drop prematurely; remaining fruits show exit holes and become deformed.
- Significant yield losses due to direct feeding and secondary infections.
Management of Okra Shoot and Fruit Borer
- Install pheromone traps at 12 per hectare for monitoring and mass trapping.
- Collect and destroy affected fruits and plant parts to reduce larval population.
- Release egg parasitoid Trichogramma chilonis (100,000/ha) and predator Chrysoperla carnea larvae (10,000/ha).
- Apply Bacillus thuringiensis (2 g/l) or dust carbaryl 10% DP (25 kg/ha) as biopesticides.
- Recommended insecticides: Azadirachtin, emamectin benzoate, phosalone, pyridalyl, quinalphos (follow label rates and safety guidelines).
Leaf Hopper (Amrasca biguttula biguttula) – Identification and Damage
- Belongs to Family: Cicadellidae; Order: Hemiptera.
- Nymphs and adults suck sap from the underside of leaves, injecting toxic saliva.
- Damage symptoms: hopper burn, leaf crinkling, browning, stunted growth, and reduced fruit set.
- Severe infestations can cause significant yield reduction.
Management of Leaf Hopper
- Remove and destroy affected plant parts to reduce pest reservoirs.
- Encourage natural enemies such as spiders (Distina albina) and chrysopids (Chrysopa cymbela).
- Apply foliar sprays of dimethoate, methyl demeton, or fipronil at recommended concentrations.
Whitefly (Bemisia tabaci) – Identification and Damage
- Family: Aleurodidae; Order: Hemiptera.
- Nymphs and adults feed on leaf sap, causing loss of plant vigor and luster.
- Acts as a vector for yellow vein mosaic virus (YVMV), leading to yellowing of veins and stunted growth.
- Heavy infestations result in significant yield losses and virus spread.
Management of Whitefly
- Remove and destroy infested plants to prevent spread.
- Use yellow sticky traps for monitoring and mass trapping.
- Apply insecticides such as acetamiprid, thiamethoxam, or profenophos at recommended rates.
Aphids (Aphis gossypii, Myzus persicae) – Identification and Damage
- Family: Aphididae; Order: Hemiptera.
- Nymphs and adults suck sap from leaves, causing yellowing, deformation, and drying of plants.
- Secrete honeydew, promoting sooty mold growth and reducing photosynthesis.
- Can transmit plant viruses, compounding crop losses.
Management of Aphids
- Seed treatment with imidacloprid or thiamethoxam for early protection.
- Use yellow sticky traps to monitor and reduce aphid populations.
- Encourage natural predators and parasitoids for biological control.
Red Spider Mite (Tetranychus telarius/urticae) – Identification and Damage
- Family: Tetranychidae; Order: Acarina.
- Colonies found on the underside of leaves, protected by silk webbing.
- Polyphagous pest infesting brinjal, okra, beans, and other crops.
- Feeding causes blotches, leaf discoloration, and eventual drying and defoliation.
Management of Red Spider Mite
- Spray wettable sulphur (3–5 g/l) or dust sulphur (20–25 kg/ha) for effective control.
- Apply dicofol (2.7 ml/l), propargite (3 ml/l), or abamectin (150 ml/ha) as acaricides.
- Repeat sprays at 10-day intervals for severe infestations.
Leaf Roller (Sylepta derogata) – Identification and Damage
- Family: Pyralidae; Order: Lepidoptera.
- Caterpillars fold leaves from tip upwards and feed within the folded area.
- Infested leaves wither, dry up, and larvae remain concealed in leaf folds.
Management of Leaf Roller
- Remove and destroy folded leaves along with larvae to reduce pest population.
- Apply carbaryl 0.2% spray or dust 10% carbaryl at 20 kg/ha for chemical control.
Objective Questions
Q1. Which distinguishing feature is correct for the adult Earias insulana moth?
A. Forewings are uniformly silvery green
B. Forewings are pale with a wedge-shaped green band
C. Forewings are brown with white streaks
D. Forewings are sky blue in color
Answer: A
Q2. What is the approximate number of generations per year for Earias spp. on okra?
A. 4
B. 8
C. 12
D. 16
Answer: C
Q3. Which insecticide and dose is correctly matched for whitefly management on okra?
A. Acetamiprid 0.4 g/l
B. Carbaryl 10% DP 25 kg/ha
C. Dicofol 2.7 ml/l
D. Imidachloprid 5 kg/seed
Answer: A
Q4. Which parasitoid is released for biological control of okra shoot and fruit borer?
A. Trichogramma chilonis
B. Chrysoperla carnea
C. Distina albina
D. Chrysopa cymbela
Answer: A
Q5. What is the main symptom of leafhopper (Amrasca biguttula biguttula) infestation on okra?
A. Hopper burn
B. Sooty mould
C. Yellow vein mosaic
D. Webbing on leaves
Answer: A
Q6. Which pest acts as a vector for yellow vein mosaic virus in okra?
A. Bemisia tabaci
B. Amrasca biguttula biguttula
C. Aphis gossypii
D. Sylepta derogata
Answer: A
Q7. Which management practice is NOT recommended for red spider mite control?
A. Spray with 0.2% sulphur
B. Spray with 0.03% dicofol
C. Spray with Bacillus thuringiensis
D. Dusting with sulphur @ 20-25 kg/ha
Answer: C
Q8. Which is a correct host plant for Earias spp. besides okra?
A. Cotton
B. Tomato
C. Potato
D. Apple
Answer: A
Q9. Which statement is true regarding the larva of Earias vitella?
A. Brownish with white streaks dorsally and pale yellow ventrally
B. Brown with a white median longitudinal streak
C. Green with black spots
D. Yellow with red bands
Answer: A
Q10. Which control measure is specific for leaf roller (Sylepta derogata) on okra?
A. Removal and destruction of leaf fold along with caterpillar
B. Spray with acetamiprid 0.4 g/l
C. Release of Trichogramma chilonis
D. Use of yellow sticky traps
Answer: A