Egyptian cotton (Gossypium barbadense) flower and boll production as affected by climatic factors and soil moisture status

The information on impact of climatic factors on cotton production is not generally available, or at least not available in the required form. Understanding this impact may help physiologists determine a possible control of the flowering mechanism in the cotton plant. Two field trials were conducted to investigate the relationships between climatic factors, soil moisture status, and flower and boll production of Gossypium barbadense. The climatic factors considered were daily maximum air temperature (°C), minimum air temperature (°C), maximum–minimum temperature (diurnal temperature range) (°C), sunshine duration (h day^?1), maximum relative humidity (%), minimum relative humidity (%), and wind speed (m s^?1). Minimum relative humidity and sunshine duration were the most significant climatic factors affecting flower and boll retention and production. Temperature appeared to be less important in the reproduction growth stage of cotton in Egypt than minimum relative humidity and sunshine duration. The soil moisture status showed low and insignificant correlation to flower and boll production. High minimum relative humidity, short period of sunshine duration, and low temperatures enhanced flower and boll formation.