Off-season Onion Cultivation
Onion is one of the most used bulbous crop in the world used in cooking vegetable as a flavoring & spice crop. Its price is so much fluctuating in Nepal due to low production within country & higher import from India which makes its supply very unstable especially during the festival periods.
Seasonal onion is harvested during Baisakh-Jestha whereas off-season onion harvesting is done during Kartik-Mangsir. Through off season cultivation, not only bulb but also leaves can be used as vegetable. It is planted from Jestha to Bhadra & harvested from Bhadra to Mangsir/Poush as off-seasonal crop. The price of onion tends to reach Rs. 125-250 per kg during Dashain Tihar season which makes this crop as golden crop for cultivation by farmers. It can be cultivated either using seedlings or through setts (small bulbs).
Detailed technique for off-season cultivation of onion through seedlings: –
- Fertile soil with good drainage facility situated at higher elevation.
- Easy irrigation facility.
- Sandy loam soil
- Less weed invasion especially mothe jhar.
- Selection of suitable variety of onion.
- Growing healthy seedlings.
- Extra vitamins, micro-nutrients & nutrition needed for better performance than seasonal cultivation.
- Earlier sprouting of bulb after harvest.
Seedling Development technique:
It can be cultivated upto 2400 meters altitude from Terai to High Hills of Nepal through this technique.
- Agrifound Dark Red
|Geographical location||Nursery time|
|Terai, Inner-Terai||Mid Ashad to Mid Shrawn|
|Low Hills||Mid Ashad to Mid Shrawn|
|Mid Hills||Mid Jestha to Ashad|
|High Hills||Mid Baisakh to Mid Jestha|
600 grams seed is essential for 1 ropani of land.
In order to kill the seed borne disease pathogens & for higher yield, seed treatment is very important. SAAF or Navistin @ 2gram/liter water/600 grams seed is used for seed treatment continued for 1 hour. After treatment seed must be shade dried before sowing in the nursery.
- Bed with 1m width & of convenient length is prepared with 20-30 cm height from ground level.
- Soil treatment with soil solarization or drenching of Navistin or Bavistin @ 2gram/liter water is done for healthy seedlings growth.
- East west direction of nursery during rainy season must be ensured.
- 5 kg FYM, 10 grams DAP, 10 grams Potash, crystal 1 gram, charged granule (Jaim) fertilizer 5 grams & 5 grams malathion is mixed and applied in 1 square meter area.
Rows are made at 7cm distance in the prepared beds with 2cm depth & seed to seed distance 1-2 cm. Cover the seed with loose soil & FYM lightly & irrigate immediately with proper mulching until germination.
- Protection from rain:
Protection from rain is primary important during off-season cultivation. For this cover the nursery bed with plastic at 1.5m height with 300-500-gauge thickness with allowing only partial sunlight to enter. For Mid-Hills, the height of plastic hemisphere must be 75 cm from the ground. Remove the plastic of this hot seed bed avoiding rain from 9 am to 3 pm.
- Plant protection:
After seedling emergence, for disease control, spray SAAF @1ml/liter water in the nursery till it wets the soil properly for 2 times. Spray multiplex @ 1ml/liter water for 2 times along with regular weeding.
Main field Preparation:
After the land selection as per mentioned in the above paragraph, it is ploughed 3-4 times, prepare the beds with 1m width & of convenient length with 20-30 cm height from ground.
Bed to bed distance is maintained as 30 cm with good drainage.
Off-season cultivation requires higher fertilizer amount than seasonal cultivation. Intermix the recommended fertilizer per ropani in the last ploughing of field.
- 1500 kg well decomposed FYM.
- 15 kg DAP, 15 kg Potash, 5kg Urea
- Mustard oil cake: 25 kg
- Liberal Boron 50 grams, Chelated Zinc 75 grams
- Biotin Lime or Biopitin Sulphur 2kg
- Meat or Blood meal: 25 kg
During sunny day, seedling transplantation must be done at the evening time. Planting distance differs according to bulb production or vegetable purpose.
Bulb production: 15-20 cm * 10-15 cm (RR * PP)
Bulb with vegetable: 10 cm * 10 cm (RR * PP)
Seedling treatment is must to prevent disease attack in seedlings before planting. Dip the seedlings in solution with Bavistin @ 2gram, HighPower @ 2ml & Streptocycline @ 1 tea spoon in 1-liter water for 30-45 minutes followed by transplanting.
Additional Manuring & Vitamins:
At 14th, 28th & 42nd day of transplanting, animal urine diluted in water or urea must be sprayed. Also apply liberal boron containing lime & boron @1gram, Calcium @ 1gram /liter water. Apply phosphorus @ 2ml/liter water after 2-3 days after transplanting. Apply Sulphur @ 15 DAT & 30 DAT.
Weeding & Irrigation:
During rainy season weed problem is recurrent in onion crop. yield loss will account 20-45% if weed control cannot be done during the initial days after transplantation. Use Targa Super @4ml/liter water herbicide for monocot weeds & Jaragon @ 3ml/liter water for dicot weeds after 10-12 days of transplantation. Hand weeding for 2 times after spraying herbicide is necessary. Irrigate if necessary. Stop irrigation 15-20 days before harvesting.
Spray Blitox 50 @ 2gram/liter water 12-15 days after transplantation. Thrips & mites are problem causing in onion which can be managed by spraying Servo Agray @ 10ml/liter water at 12-15 DAT & 30-35 DAT.
Harvesting & Yield:
For leafy vegetables, it is ready for harvesting after 60 days of transplantation. 1400-1800 kg leafy vegetable per ropani can be harvested whereas bulb is ready to harvest after 130-150 days after transplantation. Spray maleic hydrazide @ 1-2 gram/liter water 15-20 days before harvesting to prevent immediate sprouting of bulb. Average yield ranges between 1500-2000 kg bulb/ropani according to place & variety.