Evapotranspiration and water-use efficiency of chilli crop (Capsicum annum L.) in arid environment

Lysimetric studies on chilli crop Capsicum annum L. cv. Haripur and Raipur) were conducted at Jodhpur during three kharif seasons viz., 2006, 2007 and 2008 to determine evapotranspiration requirements during different growth stages under three treatments of irrigation (viz., 100% potential evapotranspiration (PET), 50% of PET and control (10 irrigations each of 30 mm depth). The crop coefficients (ratio of evapotranspiration to reference evapotranspiration) were 0.38-0.47 at early growth stage, 0.39-0.69 at vegetative stage, 0.85-1.00 at flowering/fruit formation stages and 0.34-0.91 at fruit development/maturity stage with an average value of 0.62 for the entire season. The seasonal evapotranspiration for unstressed chilli crop; (Irrigated @100%ET) was 620 mm in 2006, 548 mm in 2007 and 552 mm in 2008 with a mean of 573 mm. The highest dry fruit yield was obtained in 2008 due to the favourable weather conditions and least termite attack, resulting in highest water-use-efficiency of 1.84 kg of dry-fruit ha(-1) mm(-1) The water-use efficiency of chilli was highest (0.295-2.392 kg of dry-fruit ha(-1) mm(-)) for the crop grown at 50%ET rate of irrigation.