Effect of Organic and Inorganic Fertilizers on Growth, Yield Components and oil Production of Sunflower (Helianthus Annuus L.)

Abstract

A field experiment was conducted to evaluate the effects of organic and inorganic fertilizers on growth, yield components, seed yield, oil content and oil yield of sunflower (Helianthus annuus L.). Seven fertilizer treatments were evaluated, comprising an unfertilized control, FYM, vermicompost, 100% recommended NPK, and combinations of FYM or vermicompost with 50 or 100% recommended NPK. Fertilizer application significantly improved sunflower growth and productivity compared with the control. The highest plant height (185.4 cm), stem diameter (2.42 cm), number of leaves plant⁻¹ (30.2), head diameter (19.84 cm), seeds head⁻¹ (1,982.6), seed weight head⁻¹ (84.7 g) and 1000-seed weight (61.42 g) were recorded with FYM @ 5 t ha⁻¹ + 100% recommended NPK (T₆). The same treatment produced the maximum biological yield (12,946 kg ha⁻¹), seed yield (2,865 kg ha⁻¹), oil content (43.26%) and oil yield (1,239 kg ha⁻¹). Compared with the control, T₆ increased seed yield by 41.96% and oil yield by 62.25%. Organic amendments applied alone also improved growth and yield, although their effects were generally lower than those obtained from integrated nutrient application. The correlation analysis revealed strong positive relationships of seed yield with seeds head⁻¹ (r = 0.97**), head diameter (r = 0.95**), biological yield (r = 0.94**), stem diameter (r = 0.92**), 1000-seed weight (r = 0.91**), plant height (r = 0.89**) and oil content (r = 0.86**). Overall, FYM combined with full recommended NPK was the most effective treatment for enhancing sunflower growth, seed productivity and oil production under the experimental conditions.