Background: Nickel can act as micronutrient essential for nitrogen fixation in legume crops or it can cause toxicity when present in high concentration. Rhizospheric supplement of Nickel be at a dose not beyond its beneficial level. Methods: An experiment was conducted for mash bean genotypes to evaluate the toxic level of Nickel concentrations. Seeds of four genotypes were sown in earthen pots filled with homogenized loamy soil. Nickel was added as its chloride salt solutions at the age of twenty days @ 15.0, 30.0, 45.0, 60.0, 75.0 and 90.0 mg kg-1 soil. Yield plant-1 and its contributing factors were recorded at physiological maturity of crop. Result: At low concentration, Nickel appeared to be non toxic and high doses reduced yield attributes. The lowest significantly effective dose which affected the parameters was 45 mg kg-1 except for number of legumes plant-1 for which same was true at 60 mg kg-1. While, the most effective dose was 45 mg kg-1 for each attributes. The observations were excluded from the ongoing trend when 15 mg kg-1 Nickel reflected positive role. Of the genotypes, MASH 80 was the least productive while MASH 88 was the most productive. In terms of grain numbers, MASH 97 was the least sensitive.

The experimental studies were performed for finding antagonistic role of PGRs viz., Kinetin a Polyamine (Spermidine) for soil supplied Chromium toxicity on mash genotypes with age. Four varieties i.e., 80, 88, 97 and ES-1 were sown. Earthen pots were used and placed in complete randomization arrangement. Chromium (Cr) doses were applied @ 30mg/kg and 60mg per kg soil. This was done by adding CrCl3 salt in solutions form after 30 days of sowing. Spermidine and Kinetin were sprayed as 1.0 mM and 100.0 mM solutions respectively after 30 and 40 days of sowing. Growth analysis studies were carried when plants were of 30 and 46 days age. Chromium (Cr) at low level of concentrations in soil lowered the relative increase in plant height more effectively during growth interval 2 while, at higher toxicity levels, metal affected the shoot growth in the growth interval 1. Kinetin spray decreased the relative increase in plant height during growth interval 1while, Spermidine affected so during growth interval 1, increased the parameter. Chromium, at both levels of its concentration in soil, decreased the root growth rate more effectively during growth interval 2. Kinetin reduced relative increase in root length during growth interval 1 and increased it in the next growth interval. However, Spermidine effects started in the growth interval 1 and reached its maximum during growth interval 2. Chromium at lower concentration (30mg/kg soil) decreased the relative increase in leaf area during both intervals of growth. Exogenous Kinetin positively affected relative increase in leaf area and its effect being more pronounced in Ist interval of growth. Spermidine affected this attribute in the same manner but to lesser extent. Metal toxicity became effective during growth interval 2. Kinetin and Spermidine application to plants increased the net assimilation rate during both intervals comparatively more in growth interval