Two field experiments were conducted at the Research and Experimental Station of Moshtohor, Faculty of Agriculture during 1988 and 1989 seasons to study the effect of nitrogen, phosphorus and potassium fertilizer levels on growth charac¬ters, yield, yield components, oil content and oil yield of sunflower (Helianthus annuus, L.) var. Mayak. Application of nitrogen increased plant height, number of leaves/plant, stem diameter, leaf area dm2 /plant, head diameter, weight of head, weight of 100-seed, weight of seeds/plant, seed yield and oil yield/fad. However, oil content was signifi¬cantly decreased. Phosphorus (16 kg P205/fad.) showed a significant increase in all previous characters. All the studied characters were affected significantly by application of potassium fertilizer (24 kg K2O/fad.) except L.A. dm2 /plant and seed yield/plant. The interaction effect of nitrogen x phosphorus, nitrogen x potassium, phosphorus x potassium and nitrogen x phosphorus x potassium were not significant for all traits under study In both seasons. The highest seed yield of sunflower under study was obtained by applying 60 kg N/fad., 16 kg P205/fad. and 24 kg K20/fad to the soil. |
