Managing water deficit in wheat through mulches and irrigation techniques in semi-arid regions

Sustainable crop production with less available water is the most emerging challenge at present and in near future. There is dire need to develop techniques that give more yield with less available water. Among various techniques, the use of mulch and partial root zone drying (PRD) is easiest to implement. A two-year field experiment was conducted to evaluate the sole and combined effect of these techniques to manage water deficit in wheat. Experiment was comprised of four mulch treatments ( M0 = no mulch, M1 = black polythene mulch, M2 = wheat residue straw mulch and M4 = cotton sticks mulch) and two irrigation techniques (I1 = Normal watering and I2 = PRD technique) organized in randomized complete block design with split plot arrangement. The results revealed that less water applied at critical wheat growth stages slowdown the normal pace of important physiological processes (relative water contents, chlorophyll contents, stomatal conductance, photosynthesis,) than control irrigation treatment, but activities of important antioxidant enzymes like ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) were higher in PRD-treated plants which minimize the harmful impact of water deficit in PRD treatment. More activities of antioxidant enzymes were noted at reproductive growth stages (anthesis and grain filling) of wheat than vegetative growth stages (tillering and booting). All studied mulch materials also markedly alleviate the harmful effects of water deficit on various physiological growth stages of wheat, with best results were achieved with black plastic mulch. Maximum yield (5.10 tonnes/ha-1) and water use efficiency (2.85 kg ha-1 mm-1) were recorded in combination of black plastic mulch with PRD technique. It was concluded that combined application of mulches with PRD was more effective for water conservation, more water use efficiency and higher wheat yield than sole application of either treatment.