Estimation of Seasonal Evapotranspiration, Crop coefficient and Water Productivity of Maize and Sunflower under Drip Irrigation in Semi-arid Region of Telangana, India

Abstract:

An attempt was made to determine the seasonal evapotranspiration and crop coeffi-cient of maize and sunflower during various growth stages under drip irrigation scheduling under the semi-area of Telangana during 2013-14 and 2014-15. The re-sults revealed that grain and straw/stalk yield of maize and sunflower increased signifi-cantly at each higher level of drip irrigation up to 80%Epanand it was at par with 100% and 120% Epan in both the years and on a pooled basis. The mean daily ETcat80% Epan for maize and sunflower during its initial stage was found to be lower and almost constant (1.43 and 1.37 mm day−1) and it increased continuously during vegetative stage (2.75 and 1.50 mm day−1), flowering stage (2.96 and 5.08 mm day−1) and de-creased during the maturity stage (2.61 and 1.78 mm day−1) during both the years. The measured seasonal ETo ranged from 309.1 mm to 248.3 mm for maize and 235.2 to196.8 mm for sunflower, respectively during both the years. The highest seasonal ETc and ETc was recorded in surface check basin irrigation at IW/CPE 1 and lowest in deficit irrigation schedule i.e. drip irrigation at 40% Epan. The mean estimated crop co-efficient values for maize and sunflower at 80%Epan through drip were slightly higher over the FAO Kc values. Application of water through drip at 80% Epan registered sig-nificantly highest water productivity for both maize and sunflower crop. This study also reveals that, at any given point of time, if water scarcity is anticipated, then it is better to go for sunflower crop than maize crop which requires higher water levels to realize same net returns.