Variability of Cotton Fiber Quality within the Plant.

Cotton (Gossypium spp.) fiber uniformity is an important characteristic to textile mills. One of the greatest advantages synthetic fibers have over cotton is uniformity. Improving cotton fiber quality is difficult because of the spatial fruiting habit of the plant. In general, fiber quality tends to decline in later maturing bolls within an individual plant. This change of fiber quality can impact breeding efforts. A study was designed to determine the spatial changes in fiber traits within plants among seven contrasting genotypes. Field trials were conducted at College Station, TX, in 2009 and 2010. Cotton bolls were hand harvested from thirteen fruiting positions. Cotton fiber was measured on high-volume instrumentation (HVI) and automated fiber information system (AFIS). Results from 2009 indicate a general decline in fiber quality in upper fruiting positions, but the rate of decline varied by genotype. In addition, fiber fineness had a greater impact on an increase in neps than had been previously reported. Information from this study will be used to refine boll sampling protocols used by plant breeders developing enhanced fiber quality.