Advisory for the month of May 2022
A. For rabi onion crop ready to harvest
1. Irrigation should be stopped 10-15 days before harvesting.
2. Crop should be harvested after it attains 50% neck fall.
3. If bolting is observed, the bolted plants should be harvested immediately.
4. Harvested bulbs may be left in the field for three days for curing, bulbs covered with tops. This makes bulbs firm and dry and helps in improving shelf life.
5. After three days of field curing, the tops should be removed leaving 2.0-2.5 cm stalk above the bulbs and bulbs should be shade cured for 10-12 days for better storage.
6. Onion bulbs should be stored in bottom and side ventilated storage structures.
7. Properly graded, well cured and cleaned bulbs should be marketed for fetching better price in the market.
B. Field preparation for kharif onion nursery
For early kharif onion nursery, seeds should be sown after 15th May particularly in Karnataka and Western Maharashtra. Following points may be considered while preparing nursery.
1. About 0.05 hectare nursery area is recommended for getting seedlings to transplant in one hectare.
2. Deep ploughing is recommended for exposing the insect pupae and weed seeds to sunlight.
3. The debris of previous crops, weeds and stones should be removed before bed preparation.
4. Apply half ton of well decomposed farmyard manure in 0.05 ha.
5. Raised bed of 10-15 cm height, 1m width and length as per convenience need to be prepared.
6. Application of pre-emergence herbicide pendimethalin @ 0.2 % immediately after sowing is recommended to control weed in nursery.
7. About 5-7 kg seeds are required to raise seedlings for one hectare.
8. Seeds should be treated with thiram @ 2 g/kg seed before sowing to avoid damage from damping off disease.
9. Application of Trichoderma viride @ 1250 g/ha mixed with well decomposed FYM before sowing is also recommended to manage damping off and raise healthy seedlings.
10. Seeds should be sown in lines at 50 mm to 75 mm apart. After sowing, the seeds should be covered with fine powdered farmyard manure or compost followed by light watering.
C. For stored onion and garlic bulbs
1. The stored bulbs should be checked regularly. Rotted or infected bulbs, if any, should be removed and dumped in a pit.
2. Proper ventilation be assured and excess moisture should be avoided.
D. For standing onion seed crop ready for harvest
Those who have not yet harvested onion seed crop, they should do it now. Following points may be considered.
1. Seed umbels should be harvested when 50% of the seeds in the umbel turn black.
2. Umbels should be harvested periodically three to four times after maturity.
3. Umbels should be dried in open sun and threshing of seed can be done by rolling or threshing machine.
4. Cleaned seed should be packed in 400 Gauge poly packs after drying to <6% moisture content.