Length of crop growing season and budgeting of soil moisture for intercropping strategies in cotton

An estimation of rainfall curve through P/PET revealed that the crop growing season ranged from 22 to 44 standard week at Warangal. (Andhra Pradesh, India). Dependable rainfall at 75% probability prevailed from 24 to 38 standard week. The budgeting of water showed that there was no deficit of soil moisture until 37 standard week during two years study. Long duration crop of cotton intercropped with early maturing cowpea, greengram or blackgram significantly enhanced seed cotton equivalent yield over sole cotton. The rainfall in the later period was short of actual evapotranspiration. Therefore intercrops of longer duration viz., sesamum maturing in 75 days, soybean in 91 days and groundnut in 105 days were highly competitive and did not increase the seed cotton yield equivalents over the sole crop.