Journal of Advances in Biology & Biotechnology

Afield experiment “Influence of plant geometry and weed management strategies on productivity and profitability of sunflower (Helianthus annuus L.)” was conducted during summer season of 2023 at the Instructional Farm, OUAT, Bhubaneswar. The experiment was laid out in a factorial RBD design consisting of two plant spacings, the conventional spacing: 60 cm x 30 cm and the modified spacing: 75 cm x 25 cm and seven weed management practices consisting of total 14 treatment combinations and 3 replications. The sunflower hybrid DRSH-1 was grown as the test variety. WCE was highest in weed free treatment in all growth stages and WI (%) was minimum in Farmers’ practice (two intercultivation at 20 & 40 DAS fb one hand weeding at 30 DAS). Plant spacings did not have significant effect on growth parameters, yield attributes and on seed yield. The head diameter (17.0 cm) and test weight (56.6 g) was more in weed free and at par with Farmers’ practice (two intercultivation at 20 & 40 DAS fb one hand weeding at 30 DAS). The seed yield (2048 kg/ ha) and the oil yield (819 kg/ ha) were maximum under weed free condition and it was at par with Farmers’ practice (two intercultivation at 20 & 40 DAS fb one hand weeding at 30 DAS), One intercultivation at 20 DAS fb one hand weeding at 30 DAS and Pendimethalin @ 1.0 kg a.i. /ha as pre-emergence fb quizalofop-p-ethyl 10 EC @ 37.5 g a.i/ha at 20 DAS. The net returns (Rs. 63,121) and B:C ratio (1.99) was higher with application of Pendimethalin @ 1.0 kg a.i. /ha as pre-emergence fb quizalofop-p-ethyl 10 EC @ 37.5 g a.i/ha at 20 DAS in 75cm x 25cm plant spacing. Hence, spacing of 75cm x 25cm and weed management practice of Pendimethalin @ 1kg a.i./ha as pre-emergence fb quizalofop-p-ethyl @ 37.5 g a.i./ha at 20 DAS can be considered asthe most productive and profitable option for sunflower.