EVALUATION OF SALT TOLERANCE MUNGBEAN GENOTYPES AND MITIGATION OF SALT STRESS THROUGH POTASSIUM NITRATE FERTILIZATION

Salinity is one of the most destructive factors among the abiotic stresses, which limit the crop production considerably and ability of salt tolerance among the genotypes of a species may be varied. Appropriate nutrients application on salinity condition may alleviate its harmful effects. To achieve the aforementioned objectives, two pot experiments were performed to find out salt tolerant mungbean genotype (s) and to alleviate salinity stress through nutrient management. Eleven mungbean genotypes viz. BARI mung 2, BARI mung 3, BARI mung 4, BARI mung 5, BARI mung 6, BINA moog 1, BINA moog 2, BINA moog 5, BINA moog 6, BINA moog 7 and BINA moog 8 were screened out in three salinity levels (0, 75 and 125 mM) of NaCl. The germination of all mungbean genotypes was delayed and germination percentage was reduced with increasing level of salinity. Among the varieties, BINA moog 8 showed the best performances in terms germination and seedling growth (length, fresh and dry weights of shoot and root) and BARI mung 2 showed the least performances under saline environment. The results revealed that BINA moog 8 was the most tolerant and BARI mung 2 was the most sensitive genotype. BINA moog 8 was also used for alleviation of salinity through potassium nitrate (KNO3) application under five salinity levels (Control, 50mM salt, 50 mM salt + 10 mM KNO3, 50 mM salt + 20 mM KNO3 and 50 mM salt + 30 mM KNO3). Plants treated with 30 mM KNO3 under 50 mM salt stress produced the best growth and yield contributing characters viz. length of stem and root, no of branches plant-1, fresh and dry weight of leaf, stem and root, pods plant-1, seeds pod-1, 1000 seed weight performed better level while the least performance in respect of above traits were observed without KNO3 without stressful conditions (50 mM NaCl). Therefore, BINA moog 8 can be grown successfully at mild stress (50 mM NaCl) with application of 30 mM KNO3.