Effect of nutrients on the toxicity of pesticides carbofuran and hexachlorocyclohexane to blue-green alga Nostoc muscorum.

The effects of various levels of nutrients like potassium phosphate (dibasic), calcium nitrate, and calcium chloride individually and in combinations were studied on the toxicity of the commonly used pesticides carbofuran and hexachlorocyclohexane (HCH) in growth medium to the N2-fixing blue-green alga Nostoc muscorum. It was observed that all these chemicals had some effects on toxicity. The toxicity of both carbofuran and HCH was reduced to some extent in the presence of higher concentrations of the nutrients when compared to normal levels of the chemicals in the medium. The higher doses of nutrients in combinations antagonized the effect of individual treatment and enhanced the toxicity of pesticides.