Vegetable production

In short

Olericulture is the science of producing vegetables — annual and biennial herbaceous crops grown for their edible roots, tubers, bulbs, stems, leaves, flowers, fruits or seeds. India is the world's second largest vegetable producer after China, with roughly 200+ million tonnes a year from about 11 million hectares, led by potato, onion, tomato and brinjal; West Bengal and Uttar Pradesh top overall production, while Maharashtra dominates onion. The subject carries heavy weight in B.Sc Horticulture exams (Olericulture I and II, Seed Production, Protected Cultivation) and in ICAR-JRF/SRF, ARS and state horticulture-officer papers. Employers — seed companies (Syngenta, Nunhems, Namdhari, Mahyco, Rasi), agri-input firms, polyhouse integrators, contract-farming and retail-sourcing teams (Reliance Fresh, BigBasket, ITC), NHM/MIDH projects and FPOs — test crop-wise package of practices, seed rate–spacing–yield arithmetic and post-harvest handling in technical rounds.

Explained

Scope, classification and cropping systems

• Olericulture = vegetable science; vegetable = a succulent, usually annual plant part eaten cooked or raw, generally low in calories and rich in vitamins, minerals and fibre.
• Botanical classification (the one examiners expect): Solanaceae (tomato, brinjal, chilli, potato), Cucurbitaceae (gourds, cucumber, melons, pumpkin), Brassicaceae/Cruciferae (cabbage, cauliflower, knol-khol, radish, turnip), Fabaceae/Leguminosae (pea, cowpea, French bean, cluster bean), Malvaceae (okra), Alliaceae/Amaryllidaceae (onion, garlic), Apiaceae (carrot, coriander), Chenopodiaceae/Amaranthaceae (beet, palak, amaranth), Asteraceae (lettuce), Convolvulaceae (sweet potato), Dioscoreaceae (yam), Araceae (colocasia, elephant foot yam).
• Classification by part used: root (carrot, radish, beet), tuber (potato), bulb (onion, garlic), leafy (palak, amaranth, methi), cole (cabbage, cauliflower), fruit (tomato, brinjal, okra, cucurbits), pod (pea, beans), salad (lettuce, celery), perennial (drumstick, curry leaf, asparagus).
• Classification by temperature: cool-season — hardy (cabbage, pea, onion, garlic, spinach) and half-hardy (carrot, cauliflower, potato, beet, lettuce); warm-season — tender (tomato, chilli, French bean) and very tender (okra, cucurbits, cowpea, amaranth). Cool-season crops are *rabi* in the plains and *kharif* in the hills.
• Classification by soil reaction tolerance: very acid-tolerant (sweet potato, watermelon), moderately tolerant (tomato, carrot), sensitive (onion, cabbage, beet, cauliflower — want pH 6.0–7.0).
• Seasons: *kharif* (Jun–Oct: okra, cowpea, gourds, brinjal), *rabi* (Oct–Feb: cole crops, pea, carrot, radish, onion, potato), *zaid/summer* (Feb–May: cucurbits, okra, amaranth).
• Systems: sole cropping; intercropping (radish/palak between cole crop rows; onion with sugarcane); multiple and relay cropping; ratoon (brinjal, chilli); kitchen/nutrition garden — a 5-cent (about 200 m²) plot in 10–12 beds supplying a family of five, with perennials on the boundary and leafy crops on bund slopes; high-density planting and protected cultivation.
• Advantages of vegetable farming: short duration and quick returns, high yield per unit area, high employment per hectare, suits small holdings, nutritional security. Limitations: perishability and 15–25% post-harvest loss, price volatility (onion, tomato), heavy pesticide dependence, labour intensity, assured irrigation needed.

Nursery raising, propagation and planting

• Direct-sown crops: okra, cucurbits, pea, beans, carrot, radish, beet, palak, coriander, amaranth, methi. Transplanted: tomato, brinjal, chilli, cole crops, onion, lettuce. Vegetatively propagated: potato (tubers), garlic (cloves), sweet potato (vine cuttings), colocasia/yam (corms, setts), drumstick (seed or cuttings).
• Raised-bed nursery: bed 1 m wide × 3 m long × 15 cm high, sterilised by solarisation (transparent polythene, 25–30 µm, for 3–4 weeks in summer), formalin 2% drenching (cover 3 days, aerate 15 days) or *Trichoderma viride*/*T. harzianum* amendment; seed treated with carbendazim at 2–3 g/kg or *Trichoderma* at 4–10 g/kg.
• Protray nursery (the commercial standard): 98- or 104-cell trays with sterile coco-peat (plus vermiculite/perlite), one seed per cell, germination in a chamber then under insect-proof (40–50 mesh) net house; gives uniform, disease-free, root-intact seedlings with near-100% establishment and saves hybrid seed.
• Seedling age at transplanting: tomato/brinjal/chilli 25–35 days (4–6 leaves), cabbage/cauliflower 25–30 days, onion 6–8 weeks; hardening by withholding water and exposing to sun for 4–7 days.
• Planting methods: flat bed; ridge and furrow (cucurbits, potato); raised bed with drip and plastic mulch (tomato, capsicum, melons); pit system for cucurbits (60 × 60 × 45 cm pits, 2–3 plants per pit); paired-row on broad beds for drip economy.
• Vegetable grafting: tomato/brinjal on wild *Solanum torvum* or *S. sisymbriifolium* for bacterial wilt and nematode resistance; watermelon on bottle gourd/pumpkin for *Fusarium* and flood tolerance — tube/splice and cleft grafting are the usual methods.
• Transplanting care: evening transplanting, root dipping in *Trichoderma* or imidacloprid slurry, immediate life-saving irrigation, gap filling within a week.

Nutrient, water and canopy management

• Soil: deep, well-drained sandy loam to loam, pH 6.0–7.0, organic carbon above 0.5%; FYM 20–25 t/ha generally, up to 40–50 t/ha for potato and onion.
• Fertiliser doses vary by state package of practices; typical general recommendations (kg/ha N:P₂O₅:K₂O): tomato 100–150:60–80:60–80; brinjal 100–150:50–60:50–60; chilli 100–120:60:60; cabbage 120–150:60–80:60–80; cauliflower 120–150:60–80:60–80; onion 100–125:50:50; potato 150–180:80–100:100–120; okra 80–100:50:50; cucurbits 60–80:40–50:40–50; legumes 20–25:60–80:40–50 (nitrogen only as a starter, since they fix N). Always confirm against the local SAU recommendation and soil-test values.
• Nutrient placement: full P and K plus one-third to half N basal; remaining N in 2–3 splits at 30 and 45–60 days. Micronutrients: boron 10–15 kg borax/ha against cauliflower browning/hollow stem and beet internal black spot; molybdenum against cauliflower whiptail; calcium against tomato blossom-end rot; zinc and sulphur (onion, garlic — S improves pungency and keeping quality).
• Fertigation through drip: 100% water-soluble fertiliser gives 25–30% fertiliser saving and 20–40% yield gain; EC of the root zone kept around 1.5–2.5 dS/m.
• Critical irrigation stages: tomato — flowering and fruit development; onion — bulb formation (stop 10–15 days before harvest); potato — stolonisation and tuber bulking; cole crops — head/curd initiation; peas — flowering and pod filling. Fluctuating moisture causes fruit cracking (tomato), hollow heart and knobby tubers (potato), splitting (radish, carrot).
• Drip irrigation saves 30–50% water with 20–50% higher yield; plastic mulch (25–50 µm black or black-silver, silver side up) conserves moisture, suppresses weeds, raises early yield and repels aphids/whitefly.
• Canopy and growth operations: staking of tomato and pole beans; training on bower/pandal or trellis for pointed gourd, bitter gourd, cucumber (improves fruit quality and spray coverage); pruning to 1–2 stems in polyhouse tomato and capsicum; earthing up in potato (30–35 days, prevents greening) and onion; blanching of cauliflower curd and celery; removal of lower leaves and side shoots.
• Weed management: 2–3 hand weedings/hoeings; pre-emergence pendimethalin about 1.0 kg a.i./ha in tomato, onion, potato; metribuzin in potato; stale-seedbed technique. Follow the label approved by the Central Insecticides Board and Registration Committee (CIBRC) under the Insecticides Act, 1968.
• Growth regulators: NAA 20–50 ppm or 2,4-D 2–5 ppm for tomato fruit set in summer; ethephon for ripening; GA₃ for leafy-crop vigour; maleic hydrazide 2,500 ppm pre-harvest spray to delay onion/potato sprouting; TIBA/ethrel for sex expression in cucurbits.
• Physiological disorders (frequently asked): tomato — blossom-end rot (Ca deficiency/moisture stress), cat-face, sun-scald, fruit cracking, puffiness; cauliflower — buttoning (N deficiency/early maturity), riceyness, whiptail (Mo), browning (B), blindness; cabbage — head splitting, tip burn; potato — hollow heart, black heart (O₂ deficit in storage), greening; onion — bolting, doubles, thick neck; carrot — forking, splitting; brinjal — little leaf (phytoplasma, vector *Hishimonus phycitis*).

Crop-wise highlights, varieties and pest management

• Tomato: *Solanum lycopersicum*, self-pollinated, 2n = 24. Spacing 60 × 45 cm (open) / 60 × 30 cm (polyhouse). Varieties/hybrids — Pusa Ruby, Pusa Rohini, Arka Vikas, Arka Rakshak (triple disease resistance), Arka Samrat, Pusa Hybrid-4, Abhinav, Naveen. Key problems: early blight, late blight, bacterial wilt, ToLCV (whitefly-borne), *Tuta absoluta* (South American leaf miner, now widespread in India), fruit borer (*Helicoverpa armigera*).
• Brinjal: 60–90 × 60 cm; Pusa Purple Long, Pusa Kranti, Arka Shirish, Arka Neelkanth, Punjab Sadabahar. Shoot and fruit borer (*Leucinodes orbonalis*) is the main pest — clip and destroy infested shoots, pheromone traps at 10–12/ha. Bt brinjal is not approved for commercial cultivation in India.
• Chilli/capsicum: chilli 60 × 45 cm; capsicum largely polyhouse-grown (Indra, Bomby, Orobelle, California Wonder); thrips–mite complex causes *murda*/leaf curl; anthracnose (die-back) in chilli.
• Okra: 45–60 × 20–30 cm, seed rate 8–10 kg/ha (summer up to 15–18 kg/ha); Arka Anamika, Arka Abhay, Parbhani Kranti, Pusa Sawani (YVMV-susceptible now); yellow vein mosaic virus (whitefly) is the key constraint; harvest every 2–3 days at tender stage.
• Onion: 15 × 10 cm from seedlings, seed rate 8–10 kg/ha; Agrifound Light Red, Bhima Super, Bhima Shakti, N-53, Pusa Madhavi; thrips and purple blotch (*Alternaria porri*), Stemphylium blight. Harvest at 50–70% neck fall; curing 3–4 days in field plus 2–3 weeks in shade; ventilated bottom-and-side storage structures.
• Garlic: clove planting 15 × 10 cm, 500–600 kg cloves/ha; G-41, Bhima Omkar, Yamuna Safed.
• Potato: seed tubers 2.5–3.0 t/ha of 30–40 g size, 60 × 20 cm; Kufri Jyoti, Kufri Pukhraj, Kufri Chipsona-1/3 (processing, high dry matter and low reducing sugars), Kufri Bahar; late blight (*Phytophthora infestans*) is managed by mancozeb then cymoxanil/metalaxyl mixtures; seed produced through the seed plot technique in the Indo-Gangetic plains (aphid-free window, haulm cutting at low aphid counts) and by micropropagation/aeroponics at ICAR-CPRI, Shimla.
• Cole crops: cabbage 45 × 45 cm, cauliflower 45–60 × 45 cm. Maturity groups of cauliflower — early/Indian (Kunwari, Early Kunwari — tropical types, 20–27 °C for curding), mid (Pusa Synthetic, Improved Japanese), late/snowball (Pusa Snowball K-1, Snowball-16 — European types needing 10–16 °C, which is why snowball types bolt or fail in the plains in September).
• Cucurbits: monoecious (gourds, cucumber, pumpkin); andromonoecious (muskmelon); dioecious (pointed gourd, ivy gourd). Bitter gourd 1.5–2.0 × 0.6 m; watermelon 2.5–3.0 × 0.6–0.9 m. Pusa Vishesh, Arka Harit, Pusa Naveen (bottle gourd), Arka Manik (watermelon), Pusa Madhuras (muskmelon). Fruit fly (*Bactrocera cucurbitae*) — cue-lure traps at 10–20/ha, bait splash, destruction of fallen fruit; downy and powdery mildew; red pumpkin beetle at cotyledon stage.
• Peas and beans: pea 30 × 10 cm, 80–100 kg seed/ha; Arkel, Azad P-1, Pusa Pragati, Kashi Nandini; powdery mildew and rust; *Rhizobium* seed inoculation.
• IPM backbone: resistant varieties, crop rotation, summer deep ploughing, border crop of maize/bajra, yellow sticky traps (whitefly/aphid) and blue (thrips) at 10–12/ha, pheromone traps, *Trichogramma* and *Chrysoperla* releases, neem formulations (azadirachtin 1,500 ppm), NPV, *Bacillus thuringiensis*, need-based CIBRC-approved chemicals with the pre-harvest interval and waiting period respected — essential for FSSAI MRL compliance and for export consignments under APEDA's residue monitoring.

Protected cultivation and seed production

• Structures: naturally ventilated polyhouse (the dominant Indian type, 200 µm UV-stabilised film), fan-and-pad greenhouse, insect-proof net house (40–50 mesh), shade net (35–75%), walk-in tunnel, low tunnel (off-season cucurbit nursery in north India), plastic low-cost rain shelter.
• Suited crops: indeterminate tomato, coloured capsicum, parthenocarpic/gynoecious cucumber (seedless, no pollination needed), leafy salads, and high-value nursery raising. Yields rise several-fold — polyhouse tomato 150–250 t/ha/year against 25–40 t/ha in the open; capsicum 80–120 t/ha/year.
• Supports: drip fertigation with venturi or dosing pump, CO₂ enrichment (rarely in India), bumblebee or mechanical vibration pollination for tomato, soil solarisation/grafting against soil-borne wilt, hydroponics and NFT for leafy greens, vertical and terrace farming in cities.
• Subsidy and schemes: MIDH (Mission for Integrated Development of Horticulture) with NHM and NHB components funds polyhouses, shade nets, pack houses, cold stores and primary processing; PMKSY "per drop more crop" funds micro-irrigation; Operation Greens (TOP — tomato, onion, potato) supports price stabilisation and the cold chain; FPO promotion under the 10,000-FPO scheme. Subsidy rates and cost norms are revised periodically — check the current NHB/MIDH cost norms before quoting a figure.
• Vegetable seed production: classes are nucleus → breeder → foundation → certified, with tags — foundation white, certified blue, truthfully labelled opal/green — under the Seeds Act, 1966, Seed Rules, 1968 and Seeds (Control) Order, 1983; central certification and quality norms come through the Central Seed Certification Board and the Minimum Seed Certification Standards. (A Seeds Bill to replace the 1966 Act has been proposed repeatedly but is not yet enacted.)
• Isolation distances (MSCS, broad values): self-pollinated tomato/pea 50 m (foundation) and 25 m (certified); cross-pollinated cucurbits and onion 1,000 m (foundation) and 500 m (certified), carrot 1,000 m and 800 m, while cabbage, cauliflower and radish need 1,600 m (foundation) and 1,000 m (certified) — confirm the exact figure in the current standards.
• Techniques: seed-to-seed (onion, carrot, radish, beet) versus bulb-to-seed/root-to-seed (onion, carrot — gives better genetic purity); in-situ versus transplanted stecklings; hybrid seed production by hand emasculation and pollination (tomato), male sterility (onion — CMS, chilli, carrot), gynoecy (cucumber) and self-incompatibility (cabbage, cauliflower); roguing at vegetative, flowering and maturity stages.
• Seed quality: germination minimum generally 60–70% for most vegetables (70% tomato/brinjal/onion, 65% okra, 60% chilli and cucurbits, 75% pea and beans), genetic purity 98% (certified) and 99% (foundation); vigour tested by speed of germination and seedling-vigour index; stored at 10–15% RH equivalent moisture (5–8% seed moisture, 7–9% in moisture-pervious packs).

Harvesting, post-harvest handling and marketing

• Maturity indices: tomato — mature green, breaker, turning, pink, red-ripe (distant market harvested at breaker); okra — 4–6 days after anthesis, tender and snapping; cauliflower — compact curd before riceyness; cabbage — firm head; onion — 50–70% neck fall; potato — haulm senescence, skin set after dehaulming 10–15 days before digging; muskmelon — full slip and aroma; watermelon — dull thump, yellow ground spot, dried tendril; pea — well-filled pods, tenderometer reading.
• Operations: harvesting in cool hours → pre-cooling (room cooling, forced-air, hydro-cooling) → cleaning/washing → sorting and grading (NHB/AGMARK grade specifications; Agmark grading under the Agricultural Produce (Grading and Marking) Act, 1937) → waxing (fruit vegetables) → packing in CFB boxes or plastic crates (jute/gunny for onion and potato) → cold chain transport.
• Storage: most vegetables 0–2 °C and 90–95% RH; chilling-sensitive crops stored warmer — tomato 10–13 °C, cucumber and okra 7–10 °C, pumpkin 10–13 °C; potato 2–4 °C for table and 10–12 °C with sprout inhibitor (CIPC) for processing to avoid cold-induced sweetening; onion and garlic 0 °C or 25–30 °C with 65–70% RH (never intermediate, which triggers sprouting). Zero-energy cool chamber (double brick wall with wet sand, ICAR design) gives 10–15 °C drop for village-level holding; CA/MA packaging extends life in high-value crops; 1-MCP and ethylene management for ripening control.
• Value addition: dehydrated onion and garlic flakes/powder, tomato puree, paste and ketchup, potato chips and French fries (Chipsona varieties), frozen peas and mixed vegetables, pickles, minimally processed fresh-cuts, ready-to-eat packs.
• Regulation and marketing: FSS Act, 2006 with FSSAI contaminant/MRL regulations and the Food Safety and Standards (Packaging and Labelling) rules; Legal Metrology packaged-commodity declarations; APMC mandis and e-NAM electronic trading; direct marketing, farmer markets (Rythu Bazar, Apni Mandi), contract and institutional supply; GST on fresh unprocessed vegetables is nil, while processed vegetable products attract GST (slabs are 5%/18%/40% since 22 September 2025 — the exact rate depends on the product's classification). Organic and export produce needs NPOP certification and APEDA registration.

Key points

• Olericulture — the science of production, handling and marketing of vegetables; India is the world's second largest producer, with potato, onion, tomato and brinjal the biggest crops.
• Season classification — hardy and half-hardy cool-season crops are rabi in the plains; tender and very tender warm-season crops are kharif and summer.
• Protray nursery — one seed per cell in coco-peat under insect-proof net gives uniform, virus-free seedlings and the biggest single saving on costly hybrid seed.
• Hardening — withholding water and exposing seedlings to the sun 4–7 days before transplanting cuts transplant shock.
• Spacing drives plant population — population per hectare = 10,000 ÷ (row spacing × plant spacing in metres).
• Seed rate falls sharply with transplanting and hybrids: okra 8–10 kg/ha direct-sown against tomato 150–200 g/ha for hybrids in protrays.
• Earthing up — soil drawn to the ridge in potato and onion to prevent tuber greening (solanine) and to support bulbs.
• Blanching — excluding light from a cauliflower curd or celery stalk to keep it white and tender.
• Critical irrigation stage — the growth phase where moisture stress causes the largest yield loss; onion's is bulb formation, potato's is tuber bulking.
• Physiological disorders are nutritional or environmental, not pathogenic: whiptail (Mo), browning (B), buttoning (N), blossom-end rot (Ca/moisture).
• Key vector-borne viruses — okra YVMV and tomato ToLCV by whitefly; managing the vector, not the virus, is the control.
• Grafting on *Solanum torvum* or on bottle gourd gives soil-borne wilt and nematode resistance where rotation is impossible.
• Seed classes — nucleus, breeder, foundation (white tag), certified (blue tag), truthfully labelled; governed by the Seeds Act, 1966 and Seeds (Control) Order, 1983.
• Hybrid seed tools — hand emasculation (tomato), CMS (onion, carrot), gynoecy (cucumber), self-incompatibility (cole crops).
• Chilling injury — tomato, cucumber, okra and pumpkin are damaged below about 7–13 °C, so they are never stored at 0 °C.
• Onion and garlic storage — either near 0 °C or 25–30 °C at 65–70% RH; the intermediate band triggers sprouting.
• MIDH/NHM and PMKSY are the central schemes funding polyhouses, micro-irrigation, pack houses and cold stores; Operation Greens covers tomato, onion and potato.
• Pre-harvest interval — the minimum gap between last spray and harvest; ignoring it breaches FSSAI MRLs and rejects export consignments.

Formulas and examples

Example 1 — plant population and expected yield in tomato. Spacing 60 cm × 45 cm.

• Population = 10,000 ÷ (0.60 × 0.45) = 10,000 ÷ 0.27 = 37,037 plants/ha.
• With 25 marketable fruits per plant averaging 80 g: yield per plant = 25 × 0.080 = 2.0 kg.
• Yield = 37,037 × 2.0 = 74,074 kg = 74.1 t/ha (gross); at 10% culls, marketable ≈ 66.7 t/ha.

Example 2 — fertiliser calculation for cabbage (120:60:60 kg/ha N:P₂O₅:K₂O).

• DAP for 60 kg P₂O₅ = 60 × 100 ÷ 46 = 130.4 kg/ha; this supplies N = 130.4 × 0.18 = 23.5 kg.
• MOP for 60 kg K₂O = 60 × 100 ÷ 60 = 100 kg/ha.
• Balance N = 120 − 23.5 = 96.5 kg → urea = 96.5 × 100 ÷ 46 = 209.8 kg/ha.
• Schedule: full DAP + MOP + about 70 kg urea basal; 70 kg urea at 25 days; 70 kg urea at 45 days.

Example 3 — seed rate for okra from first principles. Spacing 45 × 20 cm; 1,000-seed weight 60 g; germination 85%, purity 98%, field establishment 85%.

• Population = 10,000 ÷ (0.45 × 0.20) = 111,111 plants/ha.
• Seeds needed = 111,111 ÷ (0.85 × 0.98 × 0.85) = 111,111 ÷ 0.708 = 156,936 seeds.
• Weight = 156,936 × 60 ÷ 1,000,000 = 9.4 kg/ha — matching the recommended 8–10 kg/ha.

Example 4 — economics of one acre of open-field tomato (illustrative; prices vary by region and season).

• Yield 25 t/acre; 24 t marketable sold at ₹8/kg = ₹1,92,000 gross.
• Net return = 1,92,000 − 1,10,000 = ₹82,000/acre; B:C ratio = 1,92,000 ÷ 1,10,000 = 1.75.
• At a distress price of ₹3/kg, gross = ₹72,000 → loss of ₹38,000 — the arithmetic behind tomato price crashes and Operation Greens.

Example 5 — drip water requirement for capsicum in a polyhouse. ETo 5 mm/day, Kc 1.05, spacing 50 × 40 cm (canopy area allotted 0.20 m²), wetting factor 1.0 (full bed wetted).

• Per plant = 5 × 1.05 × 0.20 × 1.0 = 1.05 litre/plant/day.
• Population in 1,000 m² = 1,000 ÷ 0.20 = 5,000 plants → 5,250 litre/day = 5.25 m³/day.
• Running a 2-litre/hour dripper per plant: 1.05 ÷ 2 ≈ 32 minutes/day, best split into two pulses.

Where it is used

• Seed industry: Syngenta, Bayer-Nunhems, Namdhari, Mahyco, Rasi, Sungro, East-West and NSC/state seed corporations hire for hybrid seed production, parental line maintenance, production supervision and quality-control labs.
• Protected cultivation and agri-engineering firms: polyhouse design, drip-fertigation schedules, crop consultancy for capsicum, cucumber and exotic salads around Pune, Nashik, Bengaluru, Kolar and Himachal.
• Retail and processing sourcing: Reliance Fresh, BigBasket, Zomato/Blinkit supply chains, ITC, Pepsico (contract potato for chips), Hindustan Foods and dehydration units in Mahuva and Gondal (onion/garlic flakes) — roles in procurement, grading, quality and cold chain.
• Government and development: state Department of Horticulture (Horticulture Officer, Horticulture Development Officer), NHM/MIDH project units, NHB, KVKs, ICAR institutes (IIVR Varanasi, IIHR Bengaluru, CPRI Shimla, DOGR Pune), ATMA, FPO and FPC cluster management.
• Entrepreneurship: protray nursery businesses, kitchen-garden and terrace-farming services, organic vegetable boxes, exotic vegetable production for hotels, seed dealerships licensed under the Seeds (Control) Order.
• Exams: ICAR-JRF/SRF and ARS, state PSC horticulture/agriculture officer, NABARD and bank agriculture officer, IBPS-AFO and ICAR-NET papers draw directly on spacing, seed rate, varieties and disorders.

Interview questions

• Q: Which four vegetables lead Indian production, and which states lead them? A: Potato, onion, tomato and brinjal; West Bengal and Uttar Pradesh lead overall vegetable output, Uttar Pradesh and West Bengal lead potato, Maharashtra and Madhya Pradesh lead onion.
• Q: Why is a protray nursery preferred over a raised-bed nursery for hybrids? A: It gives disease-free, uniform seedlings with the root ball intact, near-total establishment, and uses a fraction of the seed — decisive when hybrid seed costs thousands of rupees per 10 g.
• Q: How do you calculate plant population from spacing? A: Divide 10,000 m² by the product of row and plant spacing in metres; 60 × 45 cm gives about 37,000 plants per hectare.
• Q: What causes buttoning in cauliflower and whiptail? A: Buttoning comes from nitrogen deficiency or planting an early variety too late, so small curds form on stunted plants; whiptail is molybdenum deficiency, common in acidic soils.
• Q: Why do snowball cauliflower varieties fail in the plains during September? A: They are European types needing 10–16 °C for curd initiation; at plains temperatures they grow vegetatively or form loose, ricey curds.
• Q: Why is tomato not stored at 0 °C? A: It is chilling-sensitive — below about 10 °C it develops pitting, uneven ripening and loss of flavour; 10–13 °C is used instead.
• Q: What is the seed plot technique in potato? A: Producing healthy seed tubers in the Indo-Gangetic plains by planting in the aphid-free window (October), with regular aphid monitoring and haulm cutting when aphid counts cross the threshold, so virus spread is avoided.
• Q: How do you control brinjal shoot and fruit borer without heavy spraying? A: Clip and destroy wilted shoots and bored fruits weekly, use pheromone traps at 10–12 per hectare, grow resistant long types, rotate crops, and spray only on threshold with approved chemicals.
• Q: Why is onion harvested at 50–70% neck fall and then cured? A: That is physiological maturity with maximum bulb weight; curing dries the neck and outer scales, seals the bulb against rot and sets it up for months of storage.
• Q: What is the difference between seed-to-seed and bulb-to-seed in onion seed production? A: Seed-to-seed is an uninterrupted crop taken straight to flowering — cheaper but with no chance to rogue off-type bulbs; bulb-to-seed harvests and selects bulbs before replanting, giving far better genetic purity.
• Q: A grower's tomatoes show sunken black patches at the blossom end. Diagnosis? A: Blossom-end rot — a calcium transport failure from fluctuating soil moisture, high EC or excess nitrogen, not a disease; correct irrigation uniformity, mulch, and apply calcium nitrate or foliar calcium.
• Q: What does pre-harvest interval mean commercially? A: The legally and label-specified gap between the last pesticide application and harvest; violating it leaves residues above FSSAI maximum residue limits and gets consignments rejected by retailers and export buyers.
• Q: Which cucurbit needs no pollination in a polyhouse and why? A: Parthenocarpic gynoecious cucumber — it sets seedless fruit without fertilisation, which is why insect-proof polyhouses suit it.

Common mistakes

• Dividing by spacing in centimetres instead of metres (or using 1,000 instead of 10,000 m²) and reporting plant populations off by orders of magnitude.
• Forgetting that DAP already supplies nitrogen, so urea is over-applied by about 25 kg N per hectare.
• Calling physiological disorders diseases and recommending fungicides for whiptail, browning or blossom-end rot.
• Quoting one seed rate for a crop regardless of method — direct-sown, transplanted, hybrid and protray rates differ several-fold.
• Storing all vegetables at 0 °C in answers, ignoring chilling-sensitive crops and the onion/garlic double-temperature rule.
• Mixing up botanical families and pollination behaviour — stating cucurbits are self-pollinated, or giving tomato the 1,000 m isolation distance meant for cross-pollinated crops.
• Writing "spray until the pest is gone" without the economic threshold, approved label dose or pre-harvest interval.
• Quoting old scheme or subsidy percentages from a textbook; MIDH/NHB cost norms are revised periodically and must be checked before being stated.

Related topics

Fruit production · Floriculture and landscaping · Spices and medicinal crops · Plant breeding and vegetable seed technology · Post-harvest technology and value addition · Plant pathology and entomology of horticultural crops