Advisory for August 2024
A. For Transplanting Kharif Onion Seedlings
- Field Preparation:
- Plough and disk the field thoroughly to remove debris and soil clods.
- Organic Manure Application:
- Apply 15 tons per hectare (t/ha) of Farmyard Manure (FYM), or 7.5 t/ha of poultry manure or vermicompost during the last ploughing. Level the field properly before bed preparation.
- Bed Preparation:
- Use Broad Bed Furrow (BBF) method with 15 cm height and 120 cm top width, and a 45 cm furrow. This helps drain excess water and reduce anthracnose disease.
- BBF method is suitable for drip and sprinkler irrigation.
- Irrigation Setup:
- For drip irrigation, each BBF should have two drip laterals (16 mm size) at 60 cm apart with inbuilt emitters. The distance between emitters should be around 30-50 cm with a discharge flow rate of 4 L/hr.
- For sprinkler irrigation, the distance between laterals (20 mm) of micro sprinklers should be 6 m with a discharge rate of 135 L/hr.
- Chemical Fertilizer Application:
- Apply fertilizers at the rate of 75:40:40 kg N, P2O5, K2O per hectare. Also, apply sulfur based on soil sulfur content: 30 kg/ha for soils with more than 25 kg/ha available sulfur and 45 kg/ha for soils with less.
- Apply 25 kg nitrogen and the full dose of P2O5, K2O, and sulfur at planting. Apply the remaining nitrogen in two splits at 30 and 45 days after transplanting.
- For drip systems, apply 25 kg nitrogen as a basal dose during transplanting, and the rest in six splits through drip irrigation over 60 days, at 10-day intervals. Apply P, K, and S as a basal dose during transplanting.
- Biofertilizer Application:
- Use 5 kg/ha each of Azospirillum and phosphorus-solubilizing bacteria with inorganic fertilizers as a basal dose.
- Herbicide Application:
- Apply oxyfluorfen @ 23.5% EC (1.5-2.0 ml/L) or pendimethalin @ 30% EC (3.5-4 ml/L) before or during transplanting.
- Transplanting Guidelines:
- Transplant 35-40 days old seedlings at a spacing of 15×10 cm (15 cm between rows and 10 cm between plants).
- Avoid using over-aged or under-aged seedlings. Trim the top third of seedlings before transplanting.
- Dip roots in carbendazim solution (0.1%) before transplanting to reduce fungal diseases.
- Provide irrigation immediately after transplanting and three days later for good establishment.
B. For Standing Kharif Onion Crop
- If there is continuous rainfall, drain excess water properly to avoid anthracnose incidence.
- Apply first top dressing of nitrogen @ 25 kg/ha at 30 days after transplanting.
- If nitrogen deficiency appears (yellowing of leaves), apply foliar urea @ 10 g/L to correct it.
- During continuous rainfall for three days, high humidity (>85%), or cloudy conditions, apply a first prophylactic spray with benomyl @ 0.2% to control anthracnose.
- After 15 days of the first spray, apply a second spray with methomyl (0.8 g/L) and mancozeb (2.5 g/L) to manage foliar diseases and thrips.
C. For Raising Late Kharif Onion Nursery
- Use about 0.05 hectare nursery bed area and 5-7 kg of seeds to get seedlings for transplanting one hectare.
- Deep plough the soil to expose insect pupae and weed seeds to sunlight.
- Remove debris, weeds, and stones before bed preparation.
- Apply half a ton of well-decomposed farmyard manure to 0.05 ha.
- Prepare raised beds of 10-15 cm height, 1 m width, and length as convenient.
- Apply pre-emergence herbicide pendimethalin @ 0.2% to control weeds in the nursery.
- Treat seeds with carbendazim @ 1-2 g/kg seed before sowing to avoid soil-borne diseases.
- Apply Trichoderma viride @ 1250 g/ha to manage damping-off and raise healthy seedlings.
- Apply 4:1:1 kg NPK/500 m2 before seed sowing.
- Sow seeds in lines 50-75 mm apart, cover with fine powdered farmyard manure or compost, and water lightly. Use drip or sprinkler irrigation.
- Hand weed 20 days after sowing.
- Apply 2 kg N/500 m2 after hand weeding.
- Drench with metalaxyl @ 0.2% to control soil-borne diseases 10-15 days after sowing. For foliar disease incidence, apply mancozeb/tricyclozole/hexaconazole @ 0.1%.
- If thrips infestation is high, apply foliar fipronil/profenophos @ 1 ml/L.
D. For Stored Rabi Onion and Garlic Bulbs
- Monitor stored bulbs regularly for sprouting and rotting. Remove any rotted or bruised bulbs immediately. Ensure proper ventilation.
- Spread onion bulbs in heaps up to 4-5 feet high.
- Store garlic bulbs with leaves in ventilated storage structures by hanging or in circular heaps tapering towards the top.
Note: Profenophos, fipronil, and methomyl are recommended only when thrips damage is visible. Metalaxyl, benomyl, mancozeb, hexaconazole, and tricyclozole are recommended only when the disease incidence is visible.