Impact of Different Levels of Phosphorus on the Growth, Yield and Oil Content of Sunflower (Helianthus annuus L.)

Abstract

Phosphorus (P) is the second most important limiting mineral nutrient for crops. In the current study randomized complete block design was kept to determine impact of different levels of phosphorus on the growth, yield and oil content of sunflower. Experiment consists of six treatments of phosphorus levels repeated three times. The variety HO-1 was treated with different phosphorus levels: 00, 40, 50, 60, 70, and 80 kg ha^-1.Experiment analysis of variance (ANOVA) shows significant difference (P<0.05) for all growth, yield and oil content characteristics due to treatments. Maximum plant height (185.00 cm), maximum stem girth (5.00 cm), maximum head diameter (29.51 cm), maximum seed head^-1(1624.50 head^-1), maximum seed weight head^-1 (55.60g), maximum seed index (1000-seed weight, g) (105.67g), maximum seed yield (2782.2 kg) ha^-1 and maximum oil content (41.00%), were recorded in P₆ where phosphorus was applied @ 80 kg ha^-1, followed by P₅ where phosphorus was applied @ 70 kg ha^-1 with (180.58cm) maximum plant height, (4.86 cm) maximum stem girth, (24.71 cm) maximum head diameter, (1606.20 head^-1) maximum seed head^-1, (54.30 g) maximum seed weight head^-1, (105.40 g) maximum seed index (1000-seed weight, g), (2720.5kg) maximum seed yieldha^-1 and  (40.59%) maximum oil content. However, P₁ 00 kg ha^-1 (control) shows that the smallest plant height (162.18 cm), minimum stem girth (4.04 cm), minimum head diameter (24.12 cm), minimum seeds head-1 (1307.30head-1), minimum seed weight.perhead^-1 (50.70 g), seed index (103.33 g), minimum seed yield (2539kg ha^-1) and minimum oil content (39.28%). It was also observed that sunflower performance was at par with T₆ and T₅. From the present study it is concluded that sunflower performed equally better at T₅ and T₆. Hence, for economic yield T₆ is recommended. It was concluded that the impact of varying phosphorus levels on sunflower growth, yield, and oil content reveals significant correlations, emphasizing the critical role of phosphorus in optimizing sunflower productivity