Cultivation of Onion for Bulb Purpose
Raising of Seedlings:
1. Onion seedlings are raised on nursery beds prepared at high lying area.
2. Nursery beds 3 m long, 1.5 m broad and 10 cm high are prepared.
3. Seedrate is 5 to 6 kg per hectare.
4. The seed is sown crosswise in rows made 10 cm apart from each other.
5. Seed is covered by giving thin layer of soil.
6. Beds are first irrigated at 3 to 4 days interval and later on at 8 to 10 days interval.
7. Seedlings become ready for transplanting within 45 to 60 days when they attain the height of 10 to 15 cm.
Preparation of Land for Transplanting:
1. The land is ploughed 2 to 3 times.
2. Colds are crushed with the help of main or harrow.
3. 25 to 30 tons of FYM is mixed into the soil.
4. 2 to 3 harrowing are given to brought the soil to a fine tilth.
Time of Transplanting:
1. Onion can be grown at any time during the year.
2. But most suitable time for transplanting onion in Maharashtra is July in Kharif and November in Rabi.
Transplanting of Seedling:
Transplanting of onion can be done by two methods:
a) Flat Bed Method:
1. Flat beds of 4m x 2.5m sizes are prepared with the help of sara yantra.
2. The beds are soaked well by giving pre transplanting irrigation.
3. Seedlings are transplanted at 15 cm x 7 cm distance.
4. Only one healthy, vigorous growing seedling is transplanted at each spot.
5. The bulbs obtained in flat beds are medium in size but the per hectare yield is high as compared to ridge and furrow method.
b) Ridge and Furrow Method:
1. The ridges and furrows are prepared at 45 cm distance.
2. One soaking irrigations is given before transplanting.
3. Seedlings are transplanted on both the sides of the ridges by keeping 10 cm distance between two plants.
4. Only on healthy seedling is transplanted at each spot.
5. The bulbs obtained in this method are large in size but yield per hectare is less as compared to flat bed method.
Seedrate: Seedrate of onion for bulb purpose is 5 to 6 kg seed/ha.
Spacing:
a) Flat bed method – 15 x 7 cm
b) Ridge and furrow – 22.5 x 10 cm
Manuring:
1. 25-30 tons FYM per hectare is mixed into soil at the time of land preparation.
2. The dose of fertilizer is 50 kg N, 25kg P2O5 and 50 kg K2O/ha.
3. Out of this 25 kg N and complete dose of P and K is applied to the bed just before transplanting.
4. The remaining dose of 25 kg N is applied one month after transplating.
Irrigation:
1. In kharif the crop is taken on rain water and usually there is no need of irrigation.
2. In case of rabi crop first light irrigation is given just before the transplanting.
3. Second light irrigation is given 4 days after transplanting.
4. Other irrigations are given at 10 to 12 days interval in winter and at 7 to 8 days interval in summer.
5. In all it needs 15 to 18 irrigations is more at bulb development stage.
6. The need of irrigation is more at bulb development stage.
7. Irrigation shall be stopped 15 to 20 days prior to date of harvesting.
Intercultivation:
1. Weed intensity reduces the yield of bulbs thus frequent weedings are necessary to keep the field weed free.
2. Generally three hand weeding are given at one month interval after transplanting.
Harvesting:
1. Harvesting time of onion depends upon the purpose, variety and planting time.
2. For green leaves or vegetable purpose onions can be harvested at any time when leaves are green and not fibrous.
3. For bulb purpose onion become ready for harvesting in 120to 140 days.
4. At maturity the leaves turn yellow in colour and start drying form tips.
5. When 75% leaves dried and droop down harvesting is done.
6. The bulbs are pulled out by hand or dug out with the help of Kudali.
7. The leaves and roots of bulbs are cut down.
Yield:
1. Av. Yield of kharif onion – 12 to 15 tons/ha.
2. Av. Yield of rabi onion – 20 to 25 tons/ha.