INTERACTIVE EFFECTS OF SINGLE AND COMBINED HEAVY METALS ON GROWTH OF ISBGOL AND GARDEN CRESS GROWN ON HEAVY METAL CONTAMINATED SOIL

Abstract

The toxicity of Cu, Cd, Hg and their interactions on Isabgol and Garden cress were determined. The effects were defined as antagonistic, additive, or synergistic, in accordance with the sign of difference between the tested hypothesis and the value of the observed toxicity at tested combinations. The type of toxic interaction at each tested metal combination was evaluated using independent t test and welch t test. The interactive effects of heavy metal on growth of Isabgol and Garden cress was evaluated by RRG values, % phytotoxicity and root-shoot ratio of young plants using descriptive statistics as well as inferential statistics. Some of the findings are: (i) binary metal (Hg+Cd) combination has minimum Relative Root Growth in both younger and older Isabgul plant where as (cu+cd+Hg) has minimum Relative Root Growth in Garden Cress Plants. (ii) Single metal CuCl2 has minimum phytotoxicity in both younger and older Isabgul plant as well as in both younger and older Garden Cress Plants. From inferential statistics, it can be concluded that Garden Cress will have slow growth in pollutant soil in comparison of Isabgol. It can be also inferred that phytotoxicity has been highly increased in Garden Cress in comparison of Isabgol.