A Study on Relationship between Temperature and Cotton Boll Development in Xinjiang Heterosis and Gene Action of Boll Weight and Lint Percentage in High Quality Fiber Property Varieties in Upland Cotton Characteristics of Components for Cotton Single Boll Weight in Different Ecological Regions Boll Development Characteristics for High-Quality Upland Cotton Cultivars Effect of Removal of Basal Fruiting Branches on Some Premature Senescence Characters of Different Cotton Genotypes Effects of Exogenous and Physiologically Active Substances on the Development of Cotton Bolls at Low Temperature