Effects of cotton genotype, defoliation timing and season on fiber cross-sectional properties and yarn performance

Authors: LONG, ROBERT - Commonwealth Scientific And Industrial Research Organisation (CSIRO); Delhom, Christopher; BANGE, MICHAEL - Commonwealth Scientific And Industrial Research Organisation (CSIRO)

Submitted to: Textile Research Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2021
Publication Date: 2/10/2021
Citation: Long, R., Delhom, C.D., Bange, M.P. 2021. Effects of cotton genotype, defoliation timing and season on fiber cross-sectional properties and yarn performance. Textile Research Journal. 1-14. https://doi.org/10.1177/0040517521992769.
DOI: https://doi.org/10.1177/0040517521992769

Interpretive Summary: Many factors influence the performance of cotton fiber in ring spun yarns. One important factor is cotton fiber cross-sectional sizes and the aim of this research was to compare the spinning performance of two cottons which primarily differ only in cross-section. The two varieties were grown in the same field for two seasons and then subjected to early and late defoliation treatments. It was theorized that early defoliation treatments would produce cotton samples with finer cross-sections and reduced maturity. The finer fibers resulted in yarns with more fibers in the cross-section which were stronger and more uniform. Defoliation treatments impacted fiber properties to a lesser degree than genotype differences. Although later defoliation treatments produced slightly larger perimeter fibers which resulted in a premium price, the yarns were weaker and less uniform.

Technical Abstract: Cotton fiber cross-sectional properties influence the performance of ring spun yarns. The aim of this research was to compare the spinning performance of two Gossypium hirsutum L. cotton genotypes known to have different fiber fineness properties and similar other fiber properties. Genotypes were grown together in field experiments conducted over two seasons, and were subjected to early and late defoliation treatments. It was hypothesized that early defoliation would generate less mature fibers that would affect yarn properties. It was also hypothesized that different environmental conditions would influence fiber perimeter which would impact yarn performance. It was found that the genotype with lower fiber micronaire, linear density and perimeter spun yarns that were stronger and more even. Early defoliated cotton had lower micronaire and maturity ratio, but the effect on these fiber properties was less compared to the effect of genotype, and this didn’t translate into a detectable change to any yarn property. However later defoliated cotton had marginally bigger perimeter fibers, suggesting that contrary to some reports that fiber perimeter remains static during fiber development, in this case indeed fibers expanded during the secondary wall thickening phase of development. In terms of environmental effects, the first season cotton had base grade micronaire and smaller perimeter finer fibers which spun stronger and more even yarns. In contrast the second season cotton was classified into premium micronaire range even though it had bigger perimeter fibers which spun weaker and less even yarns.