Cotton Response to Seasonal Patterns of Flower Removal: I. Yield and Fiber Quality

Abstract

Cotton (Gossypium hirsutum L.) yield and quality can be affected by altered fruiting patterns related to the abscission of fruiting forms. This field study quantified the effects of flower removal during various stages of reproductive development on subsequent yield development, boll development, and fiber properties. Effects of early‐, mid‐, and late‐season flower loss on cotton reproductive development was determined. Various flower removal treatments were imposed on two cultivars at Clayton, NC, during 1991 and 1992. Early flower removal treatments (3rd week and earlier) delayed boll development, but no significant reduction in yield was found at season's end. Later flower removals (4th week and later) significantly reduced total fiber yields (13–33%) compared with early‐season removals (1st, 2nd, and through 3rd week) and no removal. Boll weight was positively correlated with fiber properties and was related to the amount of competition among developing bolls. The largest bolls resulted from treatments that had the largest negative effect on yield. Micronaire was the only fiber variable affected by flower removal, with increased values associated with later removal. Data indicate that late‐season flower losses (4th week and later) are the most injurious to yield, with significant yield reductions occurring from even the least severe, late‐season removal treatment of 6th week and later flowers. Early loss (3rd week and earlier) of fruit can be tolerated if the season allows sufficient time for compensatory reproductive growth and if further losses due to plant stress or insect damage are controlled.