Impact of Planting Time and Silicon Levels on Yield and Yield Components of Sunflower (Helianthus annuus L.)

A field study was carried out to evaluate the interactive impact of planting times of sunflower hybrid with different silicon levels on yield and yield contributing components. sunflower hybrid hysun-33 was selected as a test crop. the experiment was laid out in randomized complete block design with split plot arrangement. sowing times (10 and 15 february) were placedin main plots and silicon levels (0,23,26,69 kg ha-1) were assigned to sub plots. the crop was grown upto harvesting and data were recorded according to the standard procedures. the results showed that significantly maximum economic yield (2.60 ton ha-1) was observed in 10 february sown sunflower where silicon was applied @ 23 kg ha-1. silicon application significantly enhanced the plant height (223.92 cm),head diameter (23.83 cm),1000-achene weight (62.27 g),biological yield (10.82 t ha-1) harvest index (28.53),protein content (21.97) and oil contents (44.05%). planting time had no positive effect on achene protein and oil percentage. the interaction of early and late sown sunflower with silicon application was found non-significant.