Effects of foliar application of glycine betaine and micronutrients of zinc and manganese on morphological and physiological properties of red bean plant under salinity conditions

To investigate the effects of foliar application of glycine betaine and micronutrients of zinc and manganese on morpho-physiological traits of red bean plant under salinity stress conditions, an experiment as a factorial form in randomized complete design with three replications in the Faculty of Agriculture, Islamic Azad University, Varamin-Pishva Branch in 2019 was contacted. Experimental factors included salinity at control, 3, and 6 dS.m-1 levels, glycine betaine at application (50 mg/Lit) and non-application levels and micronutrients included zinc (50 mg/Lit), manganese (50 mg/Lit), and the combined usage (25+25 mg/Lit). The obtained results indicated that salinity stress reduced the plant height (30.31 percent), number of pods per plant (48.05 percent), number of seeds per plant (37.85 percent), seed total weight per plant (25.08 percent), SPAD index (42.98 percent), and seed protein percent (31.2 percent) and increased proline amount (43.37 percent). In general, the most effect in 6 dS.m-1 salinity was observed. The application of glycine betaine was associated with improved yield and yield components and increased SPAD index (17.28 percent), seed protein percent (6.78 percent), and proline (37.71 percent). Micronutrient foliar application showed the increasing of yield and yield components of red beans, SPAD index (29.7 percent), seed protein percent (20.67 percent), and proline (55.31 percent). In general, the most effect was obtained in the application of zinc with manganese. The results showed that the use of glycine betaine along with zinc and manganese increased proline and SPAD index increased salinity stress tolerance in red beans. It was also observed that the effect of micronutrients was greater than glycine betaine on red beans under salinity stress.