The ill-effect of increasing concentration of chromium can be ameliorated by iron and zinc application. Maize (Zea mays L.) C.V. Aruna no. 5 was grown without chromium (pure distilled water i.e. control) and with different chromium concentrations (0.1 mM, 0.5 mM, 2 mM, 5 mM in distilled water). Recovery experiments were carried out using chromium (2 mM and 5 mM) with iron and zinc (0.2 mM and 0.5 mM). The plant height, fresh weight, moisture percentage, length of cob, number of grains/cob in 0.1 mM of chromium were found to be greater than control followed by decrease up to 5 mM chromium. The dry weight decreased from lower to higher concentration with the exception of 2 mM and 5 mM chromium. The sub-optimal concentration of chromium (2 mM) with 0.2 mM and 0.5 mM Fe and Zn separately showed increase in growth and productivity. Whereas supra-optimal concentration of chromium (5 mM) with 0.2 and 0.5 mM Fe, Zn showed growth promotery results as compared to their lone concentration. The chlorophyll (a, b, total), pheophytin (a, b, total) and total carotenoids on 45th day of chromium treatment were found to be increased in 0.1 mM and 0.5 mM with respect to control while they decreased on 90th day. The total protein, sugar contents and catalase activity showed decline from control to 5 mM chromium treatment on both 45th and 90th days. Moreover, peroxidase showed higher activity with increasing concentrations of chromium. The sub-optimal (2 mM) and supra-optimal (5 mM) concentrations of chromium when taken for recovery experiments using 0.2 mM and 0.5 mM of Fe and Zn, the recovery of damage was observed with the only exception in supra-optimal level of chromium with zinc.
Chromium, Chlorophyll, Pheophytin, Carotenoid, Protein, Sugar, Catalase, Peroxidase, Zea mays
