Big Onion Cultivation PDF

06/12/2022 Cultivation of Condiments Cultivation of Onions 1. Onion - Big Onion...

06/12/2022 Cultivation of Condiments Cultivation of Onions 1. Onion - Big Onion Cluster Onion 2. Chilli Kamani Ratnayake, PhD Dept. of Horticulture & Landscape Gardening 11.11.2022 Big Onion Cultivation Coverage: Importance, Botany and Morphology Allium cepa Climatic requirements Recommended varieties Physiology of growth and yield Factors affecting bulb formation Big onion True Seed Production ©HC 21042 Kamani Ratnayake 4 Variety of onions in the world… Importance Pungency - Vital ingredient in cooking Spice - in East Vegetable - in West Traditional medicine – helps digestion and prevent muscle pain Shallot Rich source of P, Fe, Vitamin A Cash crop – good income source ©HC 21042 Kamani Ratnayake 5 ©HC 21042 Kamani Ratnayake 6 1  06/12/2022 Botany of Big Onion Stem – underground, thin, leaves form from the apical Family: Amarylidiaceae part of the stem Allium cepa ©HC 21042 Kamani Ratnayake 7 ©HC 21042 Kamani Ratnayake 8 Leaf bases – converts to sheath & cover stem Inflorescence – Umbel type, 50-200 flowers, Sheaths – form the pseudostem cross pollinated Root system- Superficial ©HC 21042 Kamani Ratnayake 9 ©HC 21042 Kamani Ratnayake 10 Seeds – Triangular, black, viability is < 1 yr Ecological Requirements Biennial plant, but grown as an annual Best adapted to DZ, during Yala Also LCIZ Long days - favourable for bulb formation Rainfall – 750 mm during growing season Need a dry, sunny weather of about 1 ½ months at crop maturity > 70% RH induce diseases Soil – prefer sandy loam/ RBE Optimum pH – 6.5-7.8 ©HC 21042 Kamani Ratnayake 11 ©HC 21042 Kamani Ratnayake 12 2  06/12/2022 Recommended Varieties Pusa Red Recommended for Sri Lankan conditions considering factors such as Developed at New Delhi, India - high yield Well adapted to DZ of Sri Lanka - seed setting ability 90 - 100 days to mature the crop - storage adaptability Average yield = about 20 - 25 t/ha - pungency High pungency, Light pink in colour - colour, etc. ©HC 21042 Kamani Ratnayake 13 ©HC 21042 Kamani Ratnayake 14 Kalpitiya selection Rampure Bulb colour is slightly pink Developed in India Well adapted to DZ Medium pungency Mature in 85- 90 days 85-90 days for maturity Yield - about 15-20 t/ha Better storability Light pink in colour High pungency ©HC 21042 Kamani Ratnayake 15 ©HC 21042 Kamani Ratnayake 16 Agri-found Light Red N 53 Developed in India by mass Takes 90-100 days for maturity selection Well adapted to DZ Bulbs are dark red As a yala crop under irrigation High pungency Pink in colour Mature in 90-100 days Average yield = about 15-20 t/ha Good storability / keeping quality ©HC 21042 Kamani Ratnayake 17 ©HC 21042 Kamani Ratnayake 18 3  06/12/2022 Nasic Red Bombay Red Mainly cultivated as a vegetable Harvest in 90 – 100 DAP Dark red in colour Dark red bulbs Poor storability High pungency Moderate storability ©HC 21042 Kamani Ratnayake 19 ©HC 21042 Kamani Ratnayake 20 Dambulla Selection Dambulu Red Locally produced recommended variety Harvest in 85 – 90 DAP Light pink colour bulbs Potential bulb yield 30 t / ha Potential seed yield 650 kg / ha High pungency Onion seeds Good storability produced in Sri Lanka Suitable for true seed production in SL ©HC 21042 Kamani Ratnayake 21 ©HC 21042 Kamani Ratnayake 22 Physiology of Growth and Yield Newly released variety Formation MIBO 1 Seedling development –Tiny embryo (1/10th of seed) –Germination in 3 - 4 days –Opt. temp. for germination – 21-27 0C –Optimum sowing depth – 6-12 mm –Further burial hinders seedling emergence ©HC 21042 Kamani Ratnayake 23 ©HC 21042 Kamani Ratnayake 24 4  06/12/2022 Growth of young plants - Vegetative phase: Cavity formation from germination to 4th leaf stage inside mature - Thickness of the main stem attains its leaves maximum ©HC 21042 Kamani Ratnayake 25 ©HC 21042 Kamani Ratnayake 26 Bulb Formation Factors affecting bulb formation - Thickening of basal part of the plant indicates bulb formation Photoperiod Mainly long day crop Prefer 12 – 15 h of day length Few short day and day neutral varieties ©HC 21042 Kamani Ratnayake 27 ©HC 21042 Kamani Ratnayake 28 Temperature Rainfall High RF at maturity - serious damages Impact couples with day length – Excess moisture - rotting of bulbs To overcome, sometimes, Ethephon is used Warm Temp +LD – Enhance bulb formation (2-chloroethyl phosphonic acid) Cold Temp +SD – Enhance leaf growth, Apply as a foliar spray delay and reduce bulb formation Accelerate bulb maturity Optimum 30 – 35 0C ©HC 21042 Kamani Ratnayake 29 ©HC 21042 Kamani Ratnayake 30 5  06/12/2022 Plant size Nitrogen level Large plants – bigger bulbs Antagonistic effect Should cut down after vegetative phase ©HC 21042 Kamani Ratnayake 31 ©HC 21042 Kamani Ratnayake 32 Flower stalk formation – Bolting If grown for bulbs, remove flower stalks manually at the initial stage Low temperature – induce bolting < 100C – immature bolting Unwanted process in commercial cultivations Reduce quality and size of bulbs ©HC 21042 Kamani Ratnayake 33 ©HC 21042 Kamani Ratnayake 34 Cultivation & Management Practices Big Onion Bulb Production Starts with ‘’true seeds’’ Nursery management Why? Small seeds – embryo 1/10 Healthy, vigorous seedlings Easy supervision Low seed requirement – 6 - 7 kg/ha (when high quality seeds are used) ©HC 21042 Kamani Ratnayake 02.12.2022 35 ©HC 21042 Kamani Ratnayake 36 6  06/12/2022 Requirements for a nursery site Steps of Nursery Preparation ? Sterilization ? ? Sequential cultivation of onion for several ? seasons - increase soil pathogens Tray nursery ©HC 21042 Kamani Ratnayake 37 ©HC 21042 Kamani Ratnayake 38 Land Preparation Fertilizer application for nursery beds Inorganic fertilizer - 1 day before sowing Requirement/bed – Urea – 15 g, TSP – 30 g, MOP – 15 g For Kalpitiya area / high sandy soils – Nursery Bed Preparation add only TSP-30 g, Size – 3 m × 1 m × 15 cm then add 15 g urea after 2 weeks Need 150 beds to provide seedlings for 1 ha 15 g MOP after 4 weeks ©HC 21042 Kamani Ratnayake 39 ©HC 21042 Kamani Ratnayake 40 Seed treatments Thiram / Captan – 4 - 6 g/kg of seeds Homai – 4 g/kg Germination – completed in 8 – 10 days Seed sowing Depth – 1 cm In rows 10 – 15 cm apart Rate – 7.5 - 8.5 kg/ha 40 - 50 g / bed 1 kg of seeds – enough for 14 - 15 beds Cover with straw mulch after seed sowing ©HC 21042 Kamani Ratnayake 41 ©HC 21042 Kamani Ratnayake 42 7  06/12/2022 Maintenance of Nursery Nursery Maintenance (contd.) Cover beds with white polythene - protect from If poor growth – heavy rains and sunlight during initial stage – add 15 g of urea/gallon of water/ bed Best time for seed sowing – Mid March-mid May Nursery period: about 1 month (35 – 42 days from sowing) Start hardening of plants 10 days before transplanting ©HC 21042 Kamani Ratnayake 43 ©HC 21042 Kamani Ratnayake 44 Field Planting of Onion Kalpitiya – No bed preparation Land and bed preparation Planted directly on flat lands Add well decomposed cattle manure (10-12 t/ha) Mainly raised beds Sunken beds for dry areas with a good drainage & sandy soil ©HC 21042 Kamani Ratnayake 45 ©HC 21042 Kamani Ratnayake 46 ©HC 21042 Kamani Ratnayake 47 ©HC 21042 Kamani Ratnayake 48 8  06/12/2022 ©HC 21042 Kamani Ratnayake 49 ©HC 21042 Kamani Ratnayake 50 Planting materials Seedlings – 4 – 5 weeks old, ≥ 3 leaves – 15 – 18 cm tall Dry sets ©HC 21042 Kamani Ratnayake 51 ©HC 21042 Kamani Ratnayake 52 Transplanting of seedlings Dip seedlings in a fungicide solution for about 5-10 min. Spacing – 10 cm × 10 cm/ 8 cm × 8 cm – 100 – 156 plants / m2 ©HC 21042 Kamani Ratnayake 53 ©HC 21042 Kamani Ratnayake 54 9  06/12/2022 Fertilizer application kg/ha – for areas except Kalpitiya Urea TSP MOP BD (1 - 2 d before planting) 65 100 50 TD1 (3 WAP) 65 - - TD2 (6 WAP) 65 - 25 ©HC 21042 Kamani Ratnayake 55 ©HC 21042 Kamani Ratnayake 56 For Kalpitiya – kg/ha Irrigation N source TSP MOP Maintain moisture in bed up to about 2 – 3 BD (1 - 2 d before 150 100 50 inch. depth during 1st week after transplanting planting) (NH4)2SO4 For sandy soil – apply water twice a day TD1 (3 WAP) 65 - - From 2nd week 3 - 4 days interval Urea Stop irrigation 2 weeks before harvesting TD2 (6 WAP) 65 - 25 Urea ©HC 21042 Kamani Ratnayake 57 ©HC 21042 Kamani Ratnayake 58 Methods of Irrigation Surface irrigation –Most popular method in the DZ –Build a bund surrounding 3 - 4 beds –Drains around each bed ©HC 21042 Kamani Ratnayake 59 MI onion fields ©HC 21042 Kamani Ratnayake 60 10  06/12/2022 ©HC 21042 Kamani Ratnayake 61 ©HC 21042 Kamani Ratnayake 62 Flooding –Mainly for sunken beds ©HC 21042 Kamani Ratnayake 63 ©HC 21042 Kamani Ratnayake 64 Micro irrigation methods Fertigation with drip irrigation Drip irrigation Application of soluble/liquid fertilizer with – Apply water to the root zone irrigation water – Reduce wastage of water by 50% – Reduce disease spread through irrigation water ©HC 21042 Kamani Ratnayake 65 ©HC 21042 Kamani Ratnayake 66 11  06/12/2022 Sprinkler irrigation Weed management Good method due to closer spacing Need only 2/3 of the water requirement Manual weeding in 3, 4 and 6 WAT of surface irrigation Carefully Chemical control – Cheaper Pre-emergent weedicides ©HC 21042 Kamani Ratnayake 67 ©HC 21042 Kamani Ratnayake 68 Harvesting and Postharvest Practices Maturity index – of Big Onion Bulbs Yellowing of leaves and 50% leaf fall at neck area (50% neck fold stage) After 85-100 days from transplanting Stop pesticide application 3 weeks before harvesting Stop irrigation 2 weeks before harvesting ©HC 21042 Kamani Ratnayake 69 ©HC 21042 Kamani Ratnayake 70 When 50% leaf fall is observed press a Air dry harvested bulbs under shade for about wooden plank on other leaves and let them 2 - 3 days in the field – increase bulb colour dry for 1 - 2 weeks and storability – narrowed neck Then harvest (uproot) all the bulbs Some farmers add maleic hydrazide before harvesting to increase storage life ©HC 21042 Kamani Ratnayake 71 ©HC 21042 Kamani Ratnayake 72 12  06/12/2022 Storing / curing 2. Cut off dried leaves leaving 1 inch above the neck and store in well ventilated racks in a Partial removal of moisture shed 2 methods 1. Tie up bulbs as a bunch using dry leaves and hang in a well ventilated place ©HC 21042 Kamani Ratnayake 73 ©HC 21042 Kamani Ratnayake 74 Importance of curing Lay bulbs in a thin layer Increase storability and reduce post harvest losses Can store about 2 t of bulbs/ 15 ×13 ft. store If well cured – Sealed neck, 2 - 3 scale leaves are dried, shiny bulbs Can supply heat during rainy periods Average yield 8 – 10 t / Ac ©HC 21042 Kamani Ratnayake 75 ©HC 21042 Kamani Ratnayake 76 Storage of onion Peak production – Aug. – Sept. Maleic hydrazide sprayed at 50% leaf fold So, need to store for 1 – 2 months stage reduce sprouting losses during storage Varieties with good storability: Over dose of N application drastically reduce the storage life ©HC 21042 Kamani Ratnayake 77 ©HC 21042 Kamani Ratnayake 78 13  06/12/2022 Bulbs could be stored up to 10 cm thickness Carbendazim sprayed to the crop ( 8 g/10 L ) without affecting the storability two weeks before harvesting decrease rotting Medium size (50-60 g) bulbs are the most losses in storage suitable for storage ©HC 21042 Kamani Ratnayake 79 ©HC 21042 Kamani Ratnayake 80 Environments with low RH ( < 80%) and moderate temperature (20 - 300C ) are Onion Pests and Diseases: suitable for storage –Practical class ©HC 21042 Kamani Ratnayake 81 ©HC 21042 Kamani Ratnayake 82 Major Pests Major Diseases Bulb rot Thrips Purple blotch Anthracnose are the major diseases in Maha season due to unfavourable weather ©HC 21042 Kamani Ratnayake 83 ©HC 21042 Kamani Ratnayake Purple blotch 84 14  06/12/2022 Anthracnose ©HC 21042 Kamani Ratnayake 85 ©HC 21042 Kamani Ratnayake 86 Big onion True Seed Production Only certain cultivars produce flowers in Sri Lanka ©HC 21042 Kamani Ratnayake 87 ©HC 21042 Kamani Ratnayake 88 06.12.2022 True seed production Select true-to-type bulbs weighing 60 - 80 g Onion seeds - Mainly imported from India Store these bulbs in a well ventilated place for about 1½ - 2 months before planting Some produced in Sri Lanka Select best bulbs from a Yala cultivation and plant at the end of December to early January (Maha season) ©HC 21042 Kamani Ratnayake 89 ©HC 21042 Kamani Ratnayake 90 15  06/12/2022 Can produce seed requirement for 1 ac by 300-500 mother bulbs Plant mother bulbs on raised beds with spacing of 22.5 x 22.5 cm ©HC 21042 Kamani Ratnayake 91 ©HC 21042 Kamani Ratnayake 92 The crop should be covered with white polythene at 3 ft height at rains and night To attract insects to increase pollination - crops like sunhemp around onion crop Mature seeds can be harvested - 3 months after planting Seeds must be well dried, if not germination ability will lose quickly ©HC 21042 Kamani Ratnayake 93 ©HC 21042 Kamani Ratnayake 94 True seed production under CIC Agribusiness poly-tunnels during Maha season Local big onion seed production in Dambulla Rainy weather during December to April - cause to fail the seed crop due to high disease incidences Therefore, grown in poly tunnels in which sides are open for ventilation Higher true seed yield can be obtained ©HC 21042 Kamani Ratnayake 95 ©HC 21042 Kamani Ratnayake 96 16  06/12/2022 ©HC 21042 Kamani Ratnayake 97 ©HC 21042 Kamani Ratnayake 98 ©HC 21042 Kamani Ratnayake 99 ©HC 21042 Kamani Ratnayake 100 30,000 kg of bulbs are used in 10 acres of land True seed production by to obtain 2000 kg of seeds. Hayleys Agriculture Ltd. ©HC 21042 Kamani Ratnayake 101 ©HC 21042 Kamani Ratnayake 102 17  06/12/2022 Cultivation in Poly tunnels by Heyleys (Dambulla) ©HC 21042 Kamani Ratnayake 103 ©HC 21042 Kamani Ratnayake 104 ©HC 21042 Kamani Ratnayake 105 ©HC 21042 Kamani Ratnayake 106 Mature seeds ready to harvest ©HC 21042 Kamani Ratnayake 107 ©HC 21042 Kamani Ratnayake 108 18  06/12/2022 Separating seeds Drying ©HC 21042 Kamani Ratnayake 109 ©HC 21042 Kamani Ratnayake 110 Mother bulb storage (Dambulla) Vernalization (Heyleys) Helps produce more flowers Keep mother bulbs at 10 - 15 0C for about 3 weeks before planting Induce flower bud formation For synchronized flower formation and seed production Can harvest at one time How is vernalization treatment done in Sri Lanka?? ©HC 21042 Kamani Ratnayake 111 ©HC 21042 Kamani Ratnayake 112 Production of Dry Sets Production of dry sets Use small cured dry bulbs obtained from Prepare nurseries in May-June for Maha nurseries after 8-10 weeks planting & Dec – Jan for Yala planting Apply 15g urea + 10g MOP in 1 gallon of water (4½ l) 3 and 5 weeks after sowing – apply water to wash off the remaining fertilizer on leaves Crop establishment using dry sets is not much popular Stop watering when plants produce about 1 cm diameter bulbs ©HC 21042 Kamani Ratnayake 113 ©HC 21042 Kamani Ratnayake 114 19  06/12/2022 After 2 weeks – carefully press the leaves with a wooden plank and let them dry When leaves are dry uproot the plants Tie up bulbs with dry leaves and hang in a well ventilated place Can use for planting after 6 - 8 weeks ©HC 21042 Kamani Ratnayake 115 ©HC 21042 Kamani Ratnayake 116 20