Evaluation of water production function and optimization of water for winter wheat (Triticum aestivum L.) under drip Irrigation

摘要

This research evaluates the performance of seven selected crop water production functions (CWPF). Tht major objective of the study was to test the capability and suitability of the different CWPF in predicting grain yield of wheat in tropical regionsof India where the crop growth period is for 100-120 days. The seven CWPF evaluated were linear, quadratic, cubic, power, Stewarts S,, Stewarts S2 and Singh et al. A field experiment was conducted during the 2012-13 and 2013-14 seasons at Jain IrrigationSystems Ltd., Jalgaor located at Western scarcity zone in Maharashtra, India. The derived functions and those previously obtained by different workers were tested against our experimental data. There was a significant correlation ol seasonal ET with yield at different irrigation levels. The test statistic of quadratic production function in2012- 13, 2013-14 and pooled basis were significantly higher than linear function. The correlation, which was quite high for linear functions (0.90 to 0.91), was even higher when evaluated in nonlinear functions (0.99). Among the all CWPF, the non-linearfunction expressed by quadratic and cubic form for grain yield performed well and thus found to represent the data well as compared with linear function. The predicted maximum grain yield of wheat was recorded at 427, 338 and 383 mm of crop ET losses during 2012-13,2013- 14 on pooled basis, respectively. The economic optima of level of irrigation that will maximize the net return under prevailing prices worked out to be 382.8 ha-mm with grain yields of 4693 kg ha1.