Influence of Indeterminate Growth Habit on Yield and Irrigation Water‐use Efficiency in Upland Cotton¹

Abstract

Based on their growth habit, 12 cultivars of upland cotton ( Gossypium hirsutum L.) were placed in four groups designated as 1) High Plains‐determinate, 2) High Plains.moderately determinate, 3) High Plains‐indeterminate, and 4) non High Plains‐indeterminate. These cultivar groups were grown at three moisture levels at Lubbock, Texas, and evaluated for their degree of indeterminate growth habit, earliness of crop maturity, lint yield, and irrigation water‐use efficiency. The purpose of our study was to determine the relationships between indeterminacy, lint yield, and irrigation water‐use efficiency. The indeterminate groups of cultivars had higher lint yields at all moisture levels than did the determinate groups. Irrigation water‐use efficiency of all cultivars was higher at the intermediate moisture level (preplant irrigation) than at the higher moisture level (full irrigation). At the intermediate moisture level, the indeterminate cu]tivars had a higher irrigation water‐use efficiency than did the determinate cultivars. The determinate cultivars had a higher irrigation water‐use efficiency than the indeterminate cultivars at the higher moisture level. Correlation analyses between individual cultivar indeterminacy values and lint yield and irrigation wateruse efficiency suggested that a cotton cultivar with a relatively inteterminate growth habit is better adapted in an environment with seasonally limited soil moisture than a cotton cultivar with a relatively determinate growth habit.