Effect of phosphorus, sulphur and boron on seed yield and quality of sunflower (Helianthus annuus)

A field experiment was conducted during the spring season of 1993 and 1994 on sandy-loam soil at Hisar, to study the effect of phosphorus, sulphur and boron on seed yield and quality of 'MSFH 8' sunflower (Helianthus annus L.). Phosphorus @ 0, 30, 60 and 90 kg/ha and sulphur @ 0,25 and 50 kg/ ha increased significantly the head diameter, 100-seed weight, seed yield/plant, seed and stalk yields/ha compared with the control during both the years. However, the effects of P @ 60 and 90 kg/ha and S @ 25 and 50 kg/ha was found similar. Oil content and yield increased due to P but protein content decreased. However, the results obtained at 60 and 90 kg P/ha were at par. Sulphur increased both the oil and protein content and oil yield over the control. Application of 0.2% borax as foliar spray at 50% flowering stage increased the head diameter, 100-seed weight, seed yield, oil content and its yield but decreased the protein content. The P and S at all levels increased the hulling (%).