Influence of planting spacing on weed suppression and performance of upland cotton

This study evaluated the influence of planting spacing on weed suppression and the performance of three upland cotton varieties (CB-15, CB-hybrid-1, and Rupali-1) during 2018-2019. The experiments involved ten planting spacings (90 cm × 60 cm, 90 cm × 45 cm, 90 cm × 30 cm, 75 cm × 60 cm, 75 cm × 45 cm, 75 cm × 30 cm, 60 cm × 60 cm, 60 cm × 45 cm, 60 cm × 30 cm, and 40 cm × 40 cm). The randomized complete block design (RCBD) with three replications was used. Results revealed that Digitaria songuilaris (Retz.) and Cyperus rotundus L. were the most dominant weed species. The variety Rupali-1 exhibited the highest weed density and dry matter, while CB-15 had the lowest. Seed cotton yield was significantly influenced by planting spacing, with the highest yield observed in CB-15 at 90 cm × 30 cm spacing, which also led to earlier squaring, flowering, and higher boll production. The variety CB-15 produced 13% and 60% higher yields compared to wider and closer spacings, respectively. These findings highlight the importance of optimized planting spacing for improved cotton yield and weed management.