Alleviation of drought stress effects on red bean by ultrasonication and foliar application of 24-epi-brassinolid

The two-location field experiment was conducted to study the possible alleviation of drought stress effects on red bean by ultrasonication and 24-epi-brassinolid. Locations were Agricultural Research Center in Shahrood, Iran and the other in bean farm, 40 km off Shahrood city in 2015. Experiment factors included irrigation of main plots at three levels of normal irrigation (60 mm evaporation from evaporation pan), mild stress (90 mm evaporation from evaporation pan) and severe stress (120 mm evaporation from evaporation pan). Stress levels were applied after 4-leaf stage and ultrasound waves treatments (in two levels of nonuse of seeds irradiation and use of irradiation for 3 minutes at 32 °C) and 24-epi- brassinolid foliar application (in two levels of nonuse of foliar application and foliar application at a rate of 0.1 mg/L at 50% flowering during two stages) which were located in sub-plots. The evaluated properties included grain yield and contents of superoxide dismutase, peroxidase, catalase, proline and ascorbate. The results showed that with severe water stress (comparison of severe stress and lack of stress), grain yield showed a significant decrease in both experiment sites, however 24-epi-brassinolid foliar application and use of ultrasonic waves in both normal and stress conditions increased the grain yield. The same condition was established for evaluated enzymes. Thus it could be stated that irradiation of ultrasonic waves and 24-epi-brassinolid foliar application for cultivating beans play important role in increment of competitive strength of plant in water deficit condition.