Central Research Institute for Dryland Agriculture, Hyderabad-500659, India
Correlations between crop and weather variables were derived for dry matter partitioning and yield components of a grain sorghum hybrid under rainfed conditions. Shoot dry matter at anthesis had positive correlation with cumulative total of daily maximum temperature, but leaf and stem dry matter at anthesis had negative correlations with cumulative total of daily minimum air temperature. Ear dry matter at anthesis had positive correlations with cumulative total of daily mean temperature, rainfall, number of rainy days and average relative humidity. So, ear development was more sensitive to moisture availability than leaf and stem growth. Grain yield, grain number m−3 and harvest index had positive correlations with rianfall, average relative humidity and cumulative total of daily mean temperature. But 1000-grain weight had significant correlation only with temperature. Temperature accounted for more variability in grain yield than did rainfall. The correlations showed that night temperature from seeding to anthesis is supra-optimal for vegetative growth and that, besides rainfall, day temperature is sub-optimal for reproductive growth and grain filing in sorghum in the rainy season.
