ONION PPT
- 1. ONION
- 2. Introduction • Common name : onion • Scientific name: Allium cepa • Family: Alliaceae • Origin: Asia
- 5. Distribution
- 13. Medicinal Value
- 18. Botany • Biennial herb • Leaves are tubular • Bulbs are formed by attachment of swollen leaf base to underground part of stem • Flowers are produced during second phase after bulb formation • Flowering structure : umbel
- 19. Types of onion 1.COMMON ONION :Allium cepa var cepa (2n=16) Most widely cultivated Large bulb Propagated through seeds Used in salad and curries
- 20. 2.Multiplier onion/potato onion : Allium cepa var aggregatum(2n=16) Small bulbs in cluster Propagated through small bulbs Used for seasoning curries
- 21. Based on color
- 27. Varieties
- 39. Cultivation Soil: • Well drained ,loose & friable • Rich in humus • Highly sensitive to acidity & alkalinity • Ph:5.8-6.5 • Clay soils are not preferred due to small and deformed bulbs are produced
- 40. Climate: • Cool and moist • Average rainfall : 75-100mm • Optimum temperature: vegetative growth :12.8-23°C bulb formation:20.25°C • Long day type cultivated in hilly tracks • Short day type cultivated in plains • Low temperature in early stage cause bolting whereas high temperature results in small sied bulb
- 41. Methods of planting 1.Broadcasting /drilling of seeds : • Direct sowing @ 30cm • Saves labour for transpalnting • High seed requirement -25kg/ha • Weeding should be done at intervals of 10days • When bulbs are 6-8 weeks old,seedling should be thinned to proper distance
- 43. 2.Transpalnting method • Most common method practiced for irrigated crops • In plains seeds are sown during October- November for a rabi crop • In hills seed are sown during March-June • Seeds are sown in well prepared nursery bed of 1.2mt width ,7.5-10cm height and conventional length • Seed rate -8-10kg/ha • Seedlings can be transplanted after 8 weeks, seedlings should be 15cm height and 0.8cm neck diameter is ideal • seedlings transplanted at spacing of 15*10cm
- 45. 3.planting of bulbs • This method practiced in hill slope and terrece cultivation • Medium to small sized bulbs are used for planting ,large sized bulbs results in early bolting ang high cost • Medium sized bulbs obtained from june crop used for planting in September-October • Bulbs are dribbled at 45*15cm • 1-1.2t of bulbs are required for planting
- 46. Manures and fertilisers • 20-25t of FYM at time of ploughing • 125kg N,75 kg P2O5,125 Kg K2O • Entire dose of p & k are applied at time of final land preparation • Nitogen to be top-dressed in 2 splits first half at 3-4 weeks after transplanting ,second half at 2 months after transplanting
- 47. Irrigation • Requirement of watere varies with stages of crop • Requires less water after establishment of seedling • Maximunm requirement of water is at maturity stage around 3 months after transplanting • In kharif 8-10 irrigations • Late kharif crops requires 12-15 irrigation • In rabi season 15-20 irrigation
- 49. Weeding and interculture • Herbicides used for control are Tenoran @ 2.5 Kg/ha 3-5 weeks after transplanting Applications of Basalin @ 1 l/ha immediately after transplanting Stomp @ 3.35 l/ha after transpalnting and before first irrigation with one hand weeding
- 50. Plant protection 1. Damping off- fusarim spp , pythium spp • Seed rotting • Pre emergence & post emergence damping off seedlings whenever onion grown from seeds • Seed treatment with thiram @2.5/kg • Drenching of nursery bed with captaf @2.5g/l of H2O
- 51. Purple blotch-Alternaria porri • Large bleached lesions with purple centre , rapidly enlarged leading to rot of infected bulbs • Spray Dithane M-45 @ 0.25% with sticker triton 0.1% first spray on appearance of disease followed by spray @ 15 days interval
- 53. Black mould :Aspergillus niger • Common storage disease • Black powdery mass of spores of black mould on exterior of scales • Colored varieties are more susceptible than white ones • Protect bulbs from moisture after harvest • Store the bulbs @ 0°C
- 55. Bottom rot / basal rot : fusarium oxysporum • Soil borne disease • Yellowing and dying back from the tips of leaves • Follow crop rotations upto 4 years • 2-3 times summer ploughing • Store the bulbs @ 0-1c • Soil drenching with captaf or thiram @0.2%
- 56. v
- 57. Thrips : Thrips tabaci • Both larvae and adults causes injury • Feed by rasping surface of leaves and sucking liberated juice • Silvery appearance • Spray 0.1% Malathion +0.1% Sandovit ,4sprays @ 15 days interval • Spray metasystox @ 1ml/l of H2O+Sandovit 0.1%
- 60. Harvesting & Yield • 3-5 months after transplanting depending on variety • Best time for harvesting of Rabi onion is one week after 50-70% neck fall • Kharif since tops do not fall but after colour of leaves changes to slightly yellow , tops start drying • Harvesting is done by pulling out plants • Average yield of big sized onions=25-30t/ha small sized onions =16-20t/ha multiplier onions =15-18t/ha
- 62. Post harvest management Drying & curing : • Drying is an additional process of aiding th skin color to remove field heat • In northern India kharif season curing requires 2- 3 weeks along with tops rabi bulbs cured in field for 3-5 days in windrow method • Curing for 10-12 days in shade helps in development of more no of skins and heir retention for longer period
- 63. Grading : • Cured bulbs are graded on size and depending on market • Big sized onions are demand in Delhi • medium to big sized onion in bangalore ,hyderabad,bhopal • Medium bulbs in kolkata ,patna • Small sized onions in north eastern regions
- 65. Storage : • Cured bulbs are stored in well ventilated rooms • Pre harvest spray o maleic hydrazide (2000-2500ppm) prevents rotting and sprouting of bulbs stored @ room temperature • At BARC,trombay irradiatin of bulbs with low doses (4000- 9000krads) of gamma rays is effective • Bulbs harvested in kharif can be stored @ 0.2-2.2c under cold storage • NHRDF&NAFED erected storage structures in Nasik i.e 3 types 1.panipat type 2 tiered 2.3tier onion store 3.2 tier model were established by government
- 66. Panipat type 2 storied structure: • Storage capacity -4t • 15% less loss than conventional method Three tier model store: pimpal gaon, nasik • Storage capacity=750t • 20% less loss than conventional method Two tier model store: lasal gaon ,nasik • Storage capacity=50t/tier • 15% less loss than conventional loss
- 67. Packaging & Transportation • Onions are packed in jute/ gunny bags • Onions stocks are transported in carts, tractors,trucks for local markets • By railway for long distance within the country • Through ventilated ships ,motor boats the onions are transported to gulf and south east asian countries
- 68. Marketing • About 60-65% is consumed internally and used as seed materials and 5% is exported • The cooperatives like NAFED plays a significant role in marketing • Lasalgaon in MAHARASTRA is the biggest onion market in India
- 69. Dehydrated onion Advantages :Storage stability and ease of preparation Commercial processing plants have a shrinkage ratio of 7:1-17:1 with moisture content of 4% Dehydreated onion sold in many forms as slices , chopped ,minced , granulated & powdered
- 70. Characteristics of dehydrated onion bulbs • White / red / yellow onion preferred • TSS should be 15-20 brix • Small neck with tall globe shape • Large bulbs • Pungency should be high • Bulbs should have good stability with minimum shrinkage and rotting • Moisture content should be around 80%
- 71. Seed production • Onion is a cross pollinated crop • Isolation distance should be 1000-1600m and 500m is recommended for certified and foundation seed production • Seed to seed method and bulb to seed methods are commonly followed
- 81. References • Text book of vegetables and tubercrops and spices-ICAR • Vegetable crops production technology- R.VHOUDHARY R.S.DHAKA