Effect of Leaf Shape on Response of Cotton to Plant Population, N Rate, and Irrigation1

Abstract

AbstractLeaves varying in shape have been identified in cotton, and it has been conjectured that leaf shape affects growth and other quantitative characters in Upland cotton, Gossypium hirsutum L.The objective of these studies was to evaluate okra and normal leaf shape on boll rot, yield, earliness, boll size, and fiber properties. Near isogenic lines of okra and normal leaf shape cotton was evaluated at three plant populations (21,780, 32,670, and 65,338 plants/ha) and three N rates (100, 134, and 168 kg/ha) on an Appling coarse sandy loam (Typic Hapludults; clayey, kaolinitic, thermic family) soil over a 3‐year period 1971‐73. In 1972 irrigation treatments were also included.No significant interactions were found between leaf characters, plant populations, N rates, and irrigation. Okra leaf shape increased earliness, boll size, and micronaire and decreased seed cotton loss due to boll rot. With increasing plant populations, lint yield and earliness tended to increase and boll size decreased. Higher boll rot loss was observed at higher levels of N. Irrigated cotton produced significantly greater lint yield, boll size, and fiber length and increased earliness.