Evaluation of Commercial Cotton Harvesting Systems in the Southern High Plains

Abstract

<abstract><title><italic>Abstract. </italic></title> Cotton production practices have changed in the Southern High Plains of the United States over the last decade resulting in increased yields and improved fiber quality. Moreover, the majority of U.S. cotton now competes in a global fiber market that demands higher quality fiber for ring spun yarn than the former domestic open-end market. The brush-roll stripper harvester is the predominate machine used to harvest the Southern High Plains cotton crop, but interest in spindle pickers has increased recently in efforts to better preserve fiber quality, enhance profitability, and maintain the market share of U.S. cotton in the global fiber market. This work was conducted to compare yields, fiber quality, and agronomic parameters between picker and stripper-based harvest systems under commercial production and ginning conditions. Large-scale harvest system comparison tests were conducted at seven sub-surface drip irrigated sites across the Texas High Plains during the 2008-2010 crop years using brush-roll strippers with field cleaners and spindle pickers. Four cotton modules harvested from each site under each harvest method were ginned by a commercial gin. Compared to picker-harvested cotton, stripper-harvested cotton had 1096 kg ha^-1 higher seed cotton yield which increased ginning charges by $72.40 ha^-1. Seed and lint yields were 217 and 108 kg ha^-1 higher, respectively, for stripper-harvested cotton resulting in $88.78 ha^-1 higher total production revenue. Notwithstanding higher lint yield for the stripper system, custom harvesting was $51.38 ha^-1 more expensive for the picker system due to the custom harvesting rates used (picking: $0.22 per lint kg; stripping: $0.18 per lint kg). Except for strength and reflectance that showed no difference by harvest method, all High Volume Instrument (HVI) fiber quality parameters were improved for picker-harvested cotton. Due to improved HVI fiber quality and a substantial decrease in the number of bark contaminated bales, lint value was higher for picker-harvested cotton. However, increased lint value was offset by decreased yield such that net revenue was $66.76 ha^-1 higher for stripper-harvested cotton across all sites.