Effects of row spacing and potassium foliar applications on yield of cotton

Abstract

Cotton (Gossypium hirsutum L.) is an important crop in drought‐prone central Texas. Foliar potassium (K) application and skip‐row planting have the potential to improve productivity of rainfed cotton in this region. The objective of this study was to quantify the effects of skip‐row planting and foliar K on cotton lint yield, biomass, nutrient uptake, and lint quality in rainfed cotton from 2017 to 2020. Foliar K was applied at 0, 20, and 40 kg ha−1. Row arrangement treatments consisted of two planting geometries: 2 × 1 skip row and standard full row. Cotton yield was not affected by foliar K in all years or by row spacing in 2017, 2019, or 2020. In 2018 alone, there was greater lint yield from skip row (530 kg ha−1) compared to full row (423 kg ha−1). The skip‐row treatment resulted in significantly lower vegetative biomass and vegetative K uptake, but improved fiber quality. While foliar K application did not impact lint yield, total biomass and vegetative nitrogen and phosphorus uptake were increased with foliar K. There were year‐to‐year differences in seed and vegetative biomass, nutrient uptake, and lint quality, likely driven by differences in rainfall, with 2018 being unusually dry. Weather variation had more impact on cotton productivity than either treatment. However, given that the skip‐row treatment increased quality and yield in the driest year while not affecting yield in wetter years makes it a viable option for cotton producers looking to reduce costs and increase profits in drought‐prone regions.