Canopy Characteristics of Narrow‐Row Cotton as Influenced by Plant Density1

Abstract

AbstractThe optimum plant density for narrow‐row cotton (Gossypium hirsutum L.) is influenced by the lint yield response to plant density as well as other crop characteristics affecting crop management. This study was conducted to quantify the effect of population density on many of these characteristics. Three experiments were conducted with narrow‐row cotton in population densities ranging from 7.1 to 22.9 plants/m2. In August plants were harvested at ground level and morphological measurements were made. At the end of the growing season lint yield was determined. There were no statistical effects of plant density on lint yield or boll and fiber properties. Population pressure increased plant height when plants were young, while the effect on older plants was inconsistent. The morphological measurements showed (a) each five plants/m2 increase in, plant population decreased the number of mainstem nodes by one, (b) each eight plants/m2 increase in population decreased the number of monopodial branches per plant by one, (c) each 11 plants/m2 increase in population density raised the lowest sympodial branch with a boll by one node. In addition increasing density from about seven to 30 plants/m2 reduced the percentage of bolls supported by monopodial branches in a curvilinear manner from 25 to 0. Increasing plant density, also increased leaf area density, especially in the central portion of the plant canopy. Considered with their probable influence on harvesting efficiency, incidence of diseases and insects, and chemical defoliation, these data should help in predicting the optimum population for narrow‐row cotton. For these studies the optimum appears to be between 10 and 15 plants/m2.