Plant nutrient management

• Yield of 2 t/ha of seed and 3.2 t/ha of stover and 0.8t/ha of roots remove 82 kg N, 13 kg P, 60 kg K, 9.4 kg S, 37 kg Ca and 22 kg Mg from the soil.
• Apply FYM @ 5-10t/ha.
• Availability of N affects Seed per head and yield of oil content.
• P and K generally improve the oil content of the seed.
• For Irrigated condition: 60:80:60 NPK kg/ha.
• For Rainfed condition: 40:50:40 NPK kg/ha.
• For Short duration cultivar: 30:40:30 NPK kg/ha.
• Apply S @ 25kg/ha to improve oil content, number of seed per head and seed weight.
• Spraying of 0.2% Borax at ray floret opening stage increase seed filling, yield and oil content.
• Spray of ZnSO4 @1% (1 kg/ha in 100 liter of water).
• N is applied in 3 split doses viz; ½ at basal, ¼ at button stage (25 DAS) and ¼ at flowering stage (45 DAS)
• In Nepal, 6 t FYM/ha and NPK @ 60:40:20 kg/ha is recommended.

Irrigation Management

• Raised as a rainfed crop in rainy season.
• Critical stages: Bud initiation (30-40 DAS), Flower opening (40-60 DAS) and Seed filling (50-80 DAS).
• Optimum depth of irrigation is 5-7cm.
• In winter season sunflower, irrigate thrice after 40, 75 and 110 DAS (4-5 leaf stage, flowering stage and grain filling stage).
• A final irrigation 14-21 days after 50% of heads have flowered gives maximum yield.

Intercultural operations

• Hand pollination to improve seed filling.
• Loss upto 30-50 % occurs due to weeds.
• Critical period is the first 30-40 DAS.
• Parasitic weed includes Orobanche cumara and Cuscuta indecora.
• Weeding and hoeing 1st at 15-20 DAS and 2nd at 30-45 DAS.
• Alachlor, Pendimethalin @1.5 kg a.i.ha as pre-emergence.
• Nitrofen @0.5 kg a.i./ha as post-emergence.

Harvesting and Threshing

• Tall cultivars are usually ready for harvesting in 120-160 DAS and short types at 50-120 DAS.
• Ready to harvest when bark of the heads turns yellow or brown, lower leaves and stem turn brown or dark brown and seed moisture content is 10-12%.
• Heads are cut manually and stacked in the threshing yard and after sun drying, they are threshed by beating with sticks.
• Moisture reduced to 10% for safe storage.
• Store in airtight metallic bins and place in dry and cool areas.

Yield

• 2-3 t/ha in sunflower growing areas.
• About 1-1.5 t/ha is possible in Nepal and India.