Field Crops> Sunflower (Helianthus annuus L.)> Manures and Fertilisers

Sunflower is an exhaustive crop and responds well to nitrogen phosphorus and potash. A crop of sunflower yielding 14 quintals of grain perhec tare exhausts 175 kg N, 65 kg P₂O₅ and 225 kg K₂O from one hectare land. Therefore, it is necessary to add adequate amount of manures an; fertilisers in the field of sunflower. Nitrogen is essential for vegetative growl' but to improve the seed size and its proper filling and to increase oil coptent liberal supply of phosphorus is essential. Potash also helps in grain filling and disease resistance. A dose of 60-80 kg nitrogen, 60 kg P₂O₅ and 40 kg K₂0 per hectare has been found optimum for sunflower. Two-third quantity of nitrogen and whole of phosphorus and potash should be applied as basal dose at the time of sowing. Remaining dose of nitrogen should be topdressed at the time of second irrigation (flowering stage).