What kind of soil suits for Onion farming? : – Onion can be cultivated in a wide range of soils from sandy loam to clay loam with good drainage facilities. The optimum ph would be 6.5 – 7.5.
Climatic conditions: – It is adapted to temperature range of 13-24ᵒ C for vegetative stage and 16-21ᵒ C for blubbing stage, 30-35ᵒ C at maturity and harvest. The best performance can be obtained in a mild weather without the extremes of cold, heat and excess rainfall.
Season:
Kharif Season May-September Onion only
Late Kharif season August-February Onion only
Rabi Season October-April Onion and Garlic
Seed quantity per hectare: – 7 to 9 kh/ha (Note: 1 ha = 2.48 acres)
Nursery raising for Onion: – Seeds are shown on raised beds of 1.2 m width and 3-4m length. The seedlings will be ready for transplanting in 454-50 days after sowing.
Preparation of soil or field: – Plough the land to get fine tilth and incorporate FYM 20 t/ha or 10 tons FYM and 5 tons poultry manure or vermin compost at the time of the ploughing. Form flat bed or broad based furrow (BBF) for planting. Spacing: – 15X10 cm for both.
Fertilizers:
Kharif season Oniion 100:50:50:50 kg NPKS/ha
Late kharif Onion 150:50:50:50 kg NPKS/ha
Rabi season Onion 150:5080:50 kg NPKS/ha
Apply 50% N and 100% P, K & S as basal dose and remaining 50% of N to be applied in two splits at 30 & 45 days after transplanting. Top dressing must be completed before bulb development.
Irrigation in Onion farming: – Irrigation is necessary at the time of transplanting/dibbling of cloves and light irrigation should be done on third day after planting and subsequent irrigation will be done at 7-10 days interval depending upon the soil condition and season. Water the transplants immediately after planting. Because of the shallow root system, onion requires frequent furrow irrigation. Avoid overhead irrigation, which causes foliage diseases. If the foliage has an unhealthy, yellowish tint the plants are being over irrigated. The soil will be overly dry around an under-watered crop and may become cracked. Onions harvest, the greater the need for water. If the onion does not get enough water it will not make a large bulb. When the necks start falling over and the onions mature, watering should be discontinued and the soil allowed drying.
Micro irrigation & fertigation in onion farming: – By using drip and sprinklers, irrigation should be done once in three days. The operating pressure for drip system is 1.5 kg/cm 2 and for rotary micro fertilizers (Urea). Apply 50% N as basal dose and remaining 50% of N to be applied in seven splits (10 days interval up to 70 days after transplanting) through drip.
Weeding control and management in onion farming: – Crop- should be kept weed free for good bulb yield. For transplanted onion, pre emergence application of Oxy-flurofen (Goal) @ 0.15-0.25 kg ai/ha or fluchloralin (Basalin) @ 1.0 kg/ha or Pendimethalin (Stomp) 3.5 l/ha combined with one hand weeding was found effective in both kharif and Rabi seasons.
For onion nursery and direct seeded crop, application of Pendimethalin @ 3ml/liter just after sowing is found best in controlling weeds without affecting the germination, seedling growth and final stand.
Cropping rotation: – Crop rotation is very important in onion farming process soybean in kharif season is the best crop rotation which improves soil fertility as well as monetary returns.
Harvesting, Yielding & storage: – Onion should be harvested at 50% neck fall stage. Follow harvesting of onion bulbs at right stage of maturity. It is important in deciding storage life of onion as bulbs may be stored for about six months.
The onion bulbs, reach maturity when the plants cease to produce new leaves and roots. In onion, neck fall is the indication of maturity. Time of harvesting depends on several factors like planting season, cultivar, market price and condition of the crop. In general, when about 50 percent neck fall is seen crop is harvested. Onion for storage should be fully developed. Thick-neck bulbs which result due to premature harvesting do not store well. Late harvesting leads to increased respiration, subsequent susceptibility to diseases and excessive sprouting during prolonged storage and left in field sunburn is also noticed. Bulbs are harvested by hand pulling if soil is light; they are also harvested by hand implements. Kharif crop, since the growth continues forced toppling should be taken up to stop growth 15 days before harvesting. Onion along with tops are kept in field for 2-3 days, curing for 3-4 days is necessary to remove excess moisture from outer skin and neck to reduce shrinkage and development of color in storage.