Investigation of Water Saving Strategies for Pinto Beans under Drought Stress

In order to evaluate methods of reduce water consumption under the conditions of drought stress in the cultivation of pinto beans, an experiment was carried out as split plot based on randomized complete block design with three replications in Salmas city, during of 2018. The main plot irrigation disruption at 3 levels (optimum irrigation, irrigation disruption at the end of flowering stage, irrigation disruption at the end of poding stage) and methods of reduce water consumption as the sub-factor in 5 levels including (control, use of superabsorbent, use of mycorrhiza fungi, use of nano-potassium fertilizer and seed priming with hydrogen peroxide) were considered. The results showed that the effect of irrigation disruption and water consumption reduction methods on yield, yield components, water use efficiency, total chlorophyll and proline content was significant. Also, the interaction of irrigation interruption factors and methods of reducing water consumption on grain yield, water use efficiency and proline was significant. Although the highest grain yield of 2133.24 kg.ha-1 was related to the experimental treatment of optimum irrigation with the use of superabsorbent polymer, but also it was observed that the experimental treatment of optimum irrigation without the use of water reduction methods by 1627.21 kg.ha-1 with experimental treatment of irrigation disruption from the end of poding stage with the use of superabsorbent at the rate of 1564.3 kg.ha-1 showed a yield increase of about 3.87% which was not statistically significant and this indicates a saving in water consumption using super absorbent. Also, in the experimental treatment of irrigation disruption in the poding stage using mycorrhizal fungus, compared to the optimum irrigation treatment, grain yield decreased by 12.3%, which indicates the greater effect of superabsorbent in preventing the reduction of grain yield compared to mycorrhizal fungus in conditions of drought stress. Also, the results showed that the water use efficiency in the experimental treatment of optimum irrigation compared to experimental treatment of irrigation disruption in the poding stage with the use of superabsorbent Decreased about 19%, which indicates an increase in water use efficiency under drought stress using superabsorbent materials.