Foliar application of Zn at flowering stage improves plant’s performance, yield and yield attributes of black gram.

Black gram plants subjected to varying levels of Zn supply (0.01 to 10 µM Zn) showed optimum growth and dry matter yield in plants receiving 1 µM Zn. The dry matter yield of plants decreased in plants receiving 0.01 and 0.1 µM Zn (deficient) and excess levels of Zn (2 and 10 µM Zn). The plants grown with Zn deficient supply showed delayed flowering, premature bud abscission, reduced size of anthers, pollen producing capacity, pollen viability and stigma receptivity resulting in poor pod formation and seed yield. Providing Zn as a foliar spray at pre-flowering stage minimized the severity of Zn deficiency on reproductive structure development and enhanced the seed nutritional status by enhancing seed Zn density, seed carbohydrate (sugar and starch content) and storage proteins (albumins, globulins, glutenins, and prolamines).

Studies on antioxidative enzymes induced by cadmium in pea plants (Pisum sativum).

Pea plants (Pisum sativum cv. Swati) exposed to different concentration of cadmium (50, 100, 200 9M Cd) under controlled glass house conditions were quantified for different physiological parameters and antioxidative enzymes. In pea plants, Cd produced a significant inhibition of growth and induced chlorosis, marginal yellowing and necrosis in young leaves, the effect being most pronounced at 200 9M Cd supply. An alteration in the activated oxygen metabolism of pea plants were also detected as evidenced by an increase in concentration of H2O2 and TBARS along with decrease in the chlorophyll and carotenoid concentration in leaves. Cadmium toxicity induced an increase in non- protein thiol, ascorbate, proline and cysteine concentration. A significant increment in the activity of SOD, APX and GR, and a decrease in CAT was observed as a result of Cd treatment. The enhanced activity of SOD and inhibition of CAT and POD produces a high build up of H2O2 which appears to be the main cause of oxidative stress due to Cd toxicity in pea plants.