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

Authors: MENEFEE, DOROTHY - Tarleton State University; Smith, Douglas; ZWONITZER, M - Grimmway Farms; COLLINS, H - Retired ARS Employee

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/14/2023
Publication Date: 9/14/2023
Citation: Menefee, D., Smith, D.R., Zwonitzer, M., Collins, H. 2023. Effects of row spacing and potassium foliar applications on yield of cotton. Agrosystems, Geosciences & Environment. 6:e20432, 1-12. https://doi.org/10.1002/agg2.20432.
DOI: https://doi.org/10.1002/agg2.20432

Interpretive Summary: Cotton is an important crop in drought-prone central Texas. During drought, potassium deficiencies can be common in field crops. Foliar potassium 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 potassium application to cotton lint yield, biomass, nutrient uptake, and lint quality in rainfed cotton from 2017 to 2020. Potassium was applied by spraying liquid fertilizer to on live plants at 0, 20, and 40 kg ha-1. Row spacing treatments consisted of two planting geometries, 2x1 skip row and standard full row. The only year where skip row had an affect was 2018, when there was greater lint yield from skip row (530 kg ha-1) compared to full row (423 kg ha-1). The skip row treatment also resulted in significantly lower vegetative biomass and vegetative potassium uptake, but improved fiber quality. While potassium fertilization did not impact lint yield; however, total biomass, vegetative nitrogen and phosphorus uptake were increased with potassium fertilization. Weather variation had more impact on cotton productivity than either treatment. 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.

Technical Abstract: Cotton is an important crop in drought-prone central Texas. Foliar potassium 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 potassium application on cotton lint yield, biomass, nutrient uptake, and lint quality in rainfed cotton from 2017 to 2020. Potassium was applied at 0, 20, and 40 kg ha-1. Row spacing treatments consisted of two planting geometries, 2x1 skip row and standard full row. Cotton yield was not affected by potassium application 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 also resulted in significantly lower vegetative biomass and vegetative potassium uptake, but improved fiber quality. While potassium fertilization did not impact lint yield, total biomass, as well as vegetative nitrogen and phosphorus uptake were increased with potassium fertilization. There were year-to-year differences in seed and vegetative biomass, nutrient uptake, and all lint quality metrics; likely driven by differences in rainfall amounts between the years with early 2018 being unusually dry. Weather variation had more impact on cotton productivity than either treatment. 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.