Genetic and Environmental Contributions to Cotton Yield and Fiber Quality in the Midsouth.

Cultivar lifespan has continued to decline in recent years. Since many new cultivars have been introduced into the MidSouth, it is worthwhile to reevaluate the genetic (G) and environmental (E) contributions to yield, turnout and fiber quality within the region. Data from large plot variety trials conducted in the MidSouth was compiled into a single dataset. States which participated in this analysis included Alabama, Arkansas, Louisiana, Mississippi, Missouri and Tennessee. Trials within each state were placed on producer farms and were managed by the producers in accordance with corresponding extension service recommendations. Due to the variability in length of growing seasons and cultivar variability across the MidSouth, cultivar entries within each state testing program varied substantially. During 2015 and 2016, a total of 102 large cultivar trials were conducted in participating states. Of these 102 locations, only 85 included DP 1522 B2XF, PHY 312 WRF and ST 4946 GLB2 and only 69 locations included DP 1522, PHY 312 WRF, PHY 444 WRF and ST 4946 GLB2. In order to determine the role of G and E for each parameter of interest, the sum of squares for cultivar and yield-environment were divided by the total model sum of squares to calculate percentage sum of squares. Since yield, turnout and certain fiber quality parameters can vary substantially between table top and MicroGins, sum of squares for these parameters were calculated separately and averaged. Preliminary analysis suggests inclusion of PHY 444 WRF into the analysis greatly increases the role of genotype in determining parameters of length and micronaire; the contributions of G to length and micronaire increased by 37.65% and 26.01%, respectively. Although environment remains the dominant parameter which producers must manipulate, this analysis suggests cultivar selection is becoming more important in determining fiber quality.