Meteorological variables of crop phenophases impact on yield and yield components of cotton (G. hirsutum L.)

Cotton is an important cash crop. Its growth and development is influenced by several environmental factors such as change in temperature, amount and distribution of rainfall and carbon dioxide concentration which attribute to climate change. A field experiment was conducted to identify critical meteorological variables of the crop growth stages of the standard weeks over deficit irrigation scheduling on growth, yield and yield components of cotton during 2014 and 2015 kharif season. The experiment was laid out with three standard weeks/ sowing time (24, 26 and 28th) and four deficit irrigation schedules (0.8, 0.6, 0.4 IW/CPE and rain fed) arranged in split plot design. Crop growth parameters, yield, yield components and weather variables were recorded during the study season. The analysis showed those meteorological variables of crop phenophases significant, positive and negative in correlation and regression with growth, yield and yield components of cotton. Among the regressed variables, over 80% impact was noticed for rainfall during square initiation growth stage; and temperature, relative humidity, rainfall, pan evaporation, stress degree day, and intercepted solar radiation during first flower; rainfall, pan evaporation and relative humidity during boll opening growth stage. Thus, it can be concluded that rainfall, maximum temperature, stress degree day, minimum and maximum relative humidity and pan evaporation were found to be significant for cotton growth, yield, and higher quality returns.