Boll Distribution and Plant Architecture of 14 Commercial Cultivars Under Five Different Irrigation Regimes

There is a pressing need to identify and understand the effects of different irrigation regimes on the boll distribution, seed cotton yield, and plant architecture of commercial cultivars of cotton (Gossypium spp.). To identify the impact of different irrigation levels on the Texas High Plains 14 commercial cultivars representing the private sector were subjected to five drip-irrigation water regimes. This study had three replications and four row plots 25 feet per entry arranged in a RCBD within each regime. Boll distribution was divided into three sections, bottom of the plant (node 7 and below), middle of the plant (node 8 to 12), and the top of the plant (node 13+). Seed cotton yield was estimated from stripper harvest of the total plot. Taproot lengths were measured to determine the differences in rooting structures. Analyses of boll distribution revealed that there were significant differences (P ≤ 0.05) between boll position of all cultivars across all water levels and cultivars within each water rate. This suggests that certain cultivars will be more beneficial under one irrigation then another. These findings also suggest that certain cultivars may perform well under multiple irrigation levels. Analyses of root length and seed cotton yield also showed significant differences (P ≤ 0.05) between cultivars under different water applications.