Genotypic and environmental contributions to lint yield, yield components, and fiber quality in upland cotton from Arkansas variety trials over a 19-year period

Lint yields and their underlying yield components can be substantially influenced by genotype and environment. Thus, the objectives of the current study were to quantify genotypic and environmental contributions to lint yield, yield components, and fiber quality in multi-site variety trials conducted in Arkansas over a 19-year period, to identify the traits most strongly associated with lint yield, and to quantify long-term trends in the aforementioned traits. Annual assessments included lint yield, seeds per hectare (SPH), intra-boll yield components, and fiber quality parameters. Production environment accounted for a higher percentage of all yield variability in 15 out of 19 years. However, four years were identified in which genotypic contributions were greater than environmental contributions. Genotype was a dominant driver of variability in lint percent, lint index, seed score, seed index, fibers per seed, fiber density, fiber length, strength, and uniformity. Production environment was the dominant driver of variability in SPH, and micronaire. Correlations between yield components and yield varied substantially from year to year, even when genotype was the primary yield driver. A regression function that utilized lint index and SPH was a stronger and more consistent indicator of genotypic variation in lint yield than any single yield component. Finally, long-term trends show that lint percent has increased significantly over the past 19 years, whereas seed index has declined 19.6% for cotton varieties with the highest lint yields.