Abstract:

To grasp the microclimate environment in the cotton population structure, the influence of different cotton densities on yield was determined. Six different densities were designed to determine agronomic traits, and the microclimatic elements in the field of different cotton densities were measured by selecting the flowering bloom period with the highest cotton density. The results showed that the agricultural traits of cotton varied greatly with density, and the climatic factors such as light, temperature, and humidity changed considerably among the groups. With the increasing of density, agricultural traits of cotton, including plant height, stem diameter, number of leaves, number of fruiting branches, number of buds and bolls, and boll weight, were significantly and negatively correlated with the gradient temperature difference between cotton plants, while positively correlated with the light transmittance. The gradient temperature difference between cotton plants of the optimal density group should be less than 0.3-0.4℃, and the light transmittance between cotton plants should be above 5.5%. The density of 225000 plants/hm² showed the best yield performance, followed by 270000 plants/hm², and then 180000 plants/hm². Under the current cultivation and management level, the planting density of early maturing cotton in northern Xinjiang should be designed at 200000-250000 plants/hm².

Key words: cotton, density, microclimate, agronomic trait, yield