Association of weather variables with yield and yield components of cotton (Gossypium hirsutun L.) at reproductive phenophase

Growth and development of cotton is influenced by several environmental factors such as fertility and biology of soil, change in temperature, amount and distribution of rainfall and carbon dioxide concentration which are attributes of climate change. A field experiment was conducted to study the contribution of weather variables for the total variation in yield and yield components during reproductive phenophase of cotton (square initiation to boll opening) during 2013-14 and 2014-15 kharif season. The experiment was set out with three sowing time (24, 26 and 28 standard week) as main plot, three deficit irrigation schedules (0.8 IW/CPE, 0.6 IW/CPE and 0.4 IW/CPE) and rainfed as sub plot in split plot design. The result indicated that significant effect of sowing time on yield and yield components of cotton where maximum number of bolls per plant, boll weight, hundred seed weight, ginning percent, and seed cotton yield attained on early sown cotton. Weather variables showed significant correlation with yield and yield components. Results of regression analysis suggested that weather variables such as maximum temperature, mean temperature, relative humidity I and relative humidity II were found to be influential and accounted for over 90% of total variation in seed cotton yield and yield components during the reproductive phenophase.