Impacts of wide row spacings on yield and yield components of upland cotton (Gossypium hirsutum L.)

Abstract

This study quantifies the effects of wide row spacing on lint yield, yield components, and fiber quality of upland cotton (Gossypium hirsutum L.). An experiment was conducted in Tifton, GA in 2021 and 2022, where cotton was planted in six replications of 91-, 122-, 152-, and 183-cm row spacings. Following defoliation, 1.8 m was hand harvested from each plot, and boll density plant⁻¹ and density ha⁻¹ were determined for sympodial and monopodial branches. Additional measurements included fruit and lint yield distribution assessments and intra-boll yield components including seed cotton weight boll⁻¹, seed index, seed boll⁻¹, lint weight seed⁻¹, seed surface area (SSA), fiber density, and single fiber weight. Lint yield was reduced 20% in the 183-cm row spacing compared to the 91-cm row spacing. The 91-cm rows had the lowest number of sympodial bolls plant⁻¹ with 152- and 183-cm rows demonstrating a 24%–28% increase in sympodial bolls plant⁻¹. Sympodial bolls ha⁻¹ were reduced 22% in the 183-cm row spacing compared to the 91-cm row spacing. There were no differences in bolls ha⁻¹ or lint yield ha⁻¹ with respect to monopodial growth. There were no differences in seed cotton weight boll⁻¹, seeds boll⁻¹, fiber density, single fiber weight, or turnout. Seed index and SSA were increased in the 183-cm row spacing. Lint weight seed⁻¹ was reduced in the 91-cm row spacing.