Effect of seed rate and manual weeding on weed infestation and subsequent crop performance of sesame (Sesamum indicum L.)

Abstract

Crop-weed competition has a profound effect on the seed yield of sesame. We evaluated the effects of both the seed rate and weeding regime on the weed infestation and crop performance of sesame. Two factors viz seed rate (6, 7, 8, 9 or 10 kg ha-1) and weeding regimes (no weeding, single-weeding, weeding twice, and complete weeding) were included in the experiment. The experiment was implemented in a split-plot design accommodating seed rate in the main plot and weeding regime in the subplot with three replications. Mean data from the two-year experiment showed that weed density and weed dry weight were significantly affected by seed rate: these two variables decreased with the increase in the seed rate (p <0.01). The seed rate significantly influenced myriad different variables that included: the plant population, plant height, number of branches per plant, number of infertile flowers per plant, number of seeds per capsule, 1000 seed weight, seed yield, stove yield and harvest index. Two factors, number of seeds per capsule and 1000 seed weight, were significantly decreased by variations in weeding regime (p <0.01). The plant population decreased significantly with increasing weeding frequency. Seed yield, stover yield and their attributes were significantly improved in the weeded crop than in the non-weeded one. The weed free and two weeding treatments resulted in better yield performance compared to the weeding treatments. Overall, the interaction effect of seed rate and weeding regime was not significant in respect to the plant characteristics and seed yield. Nevertheless, a seed rate of 9 kg ha-1, coupled with twice manual weeding, illustrated the best seed yield. Therefore, crop competition can be explored as an effective alternative weed management strategy and achieving optimal yield of sesame.