Integrated Weed Management of Cotton Planting in Conventional and Ultra-Narrow Row Space

To determine the most appropriate method of weed management in conventional row and ultra narrow row spacings of cotton, a factorial experiment was based on a randomized complete block design with three replications was conducted in Sabzevar in 2015-2016. Factors under study were plant spacings in two levels, conventional (70 cm row spacing) and ultra-narrow row (20 cm row spacing) and weed management in six levels: without controlling of weeds (control), application of herbicide at recommended dose of Ethalfluralin (Treflan 48% EC) at 1160 g/ai ha), application of herbicide at 50% recommended dose + hand weeding at 45 days after emergence (DAE), application of herbicide at 50% recommended dose + two times hand weeding at 30 and 60 DAE, three times hand weeding at 30, 45 and 60 DAE, and full weed free condition. The results showed that traits like weed density, by 33.71 percent, lateral branches by 14.77 percent, number of bolls per plant by 16.88 percent, and boll weight by 12.30 percent were lower in narrow row spacing, while seed cotton yield by 39.85 percent and fiber yield by 23.71 percent higher, as compared to, conventional row spacing. In the conventional cultivation system, if 50% of the herbicide dose is reduced, it needs two hands weeding at 30 and 60 DAE; while in ultra-narrow row spacing condition, with a 50% reduction in the recommended herbicide dose, one hand weeding at 45 DAE is needed to achieve suitable seed cotton yield. As a whole, the results showed that, under ultra-narrow row spacing, with a 50% reduction in herbicide dose and reduced weed control times (only one hand weeding at 45 DAE) it can be obtained seed cotton yield similar to other control treatments.