Effects of different defoliaton timings on nep and seed coat fragment formation and fiber quality of cotton cultivars

This study was conducted to determine the effects of different defoliation timing treatments on nep and seed coat fragment formation and fiber quality properties of three cotton varieties having different maturing in 2019 at Çukurova University, Cotton Research and Application Center. Trial was arranged in a split-plot system in a randomized complete block with three replicates and defoliation timing were maintained as main plots, while the cultivars were in the sub-plots. There was a strong effect of defoliation timing treatments on fiber length and fiber maturity ratio. Varieties significantly varied in terms of fiber fineness, fiber length, fiber strength, short fiber content, reflectance value, trash size, total nep count, total nep mean size, fiber nep count. Although no significant differences were found among defoliation timing treatments, fiber nep coun varied between 42.56 and 46.33 per gram, seed coat nep counts varied between 25.11 and 29.33 per gram and trash counts varied between 78.11 and 84.89 per gram. For fiber quality, it can be concluded that defoliation timing treatments had no significant impact on quality properties except fiber length and maturity ratio.