Minimizing Immature Fiber and Neps in Upland Cotton

Abstract

Immature cotton (Gossypium hirsutum L.) fibers and neps in ginned cotton will affect textile quality and thus can affect overall industry reputations. This study conducted three field studies that systematically varied the timing of harvest aid application to generate differences in the amount of immature fiber and levels of neps in crops at harvest. The aim was to ascertain what crop conditions (percent open bolls, number of immature bolls, percent immature bolls, and percent immature lint mass) at the time of application contribute to these differences, and assess whether these outcomes are influenced by 0, 1, 2 lint cleaning passes. Earlier harvest aid treatments increased neps and the level of neps was best related to fiber linear density (r2 = 0.78). All measurements of crop condition at harvest aid application explained changes in yield and fiber properties well, although the percent immature bolls (r2 > 0.67) can be applied when crops are nonuniform in their maturity, and when they contain fruiting gaps. Relationships between lint cleaning passes and crop condition at harvest aid application showed an interaction between earlier harvest treatments and lint cleaning passes. One lint cleaning pass contributed between 95 and 141 count g−1 more neps, while a second pass added between 101 and 181 count g−1 more neps. This information will be valuable in refining strategies that aim to optimize both yield and fiber quality (including less neps). This study also supported the current recommendation of applying harvest aids at 60% open bolls.