Combined Phytotoxicity of Endosulfan-Sulfate and Heptachlor on Seedling Growth of Various Crops

Abstract

Combined phytotoxicity of endosulfan-sulfate and heptachlor at total concentration (ratio 1:1) ranging from 0.4-40 mg/kg dried soil on seedling growth of four crops was investigated. Oryza sativa var. glutinosa cv. RD6, Ipomoea aquatic. Vigna sinensis and Brassica alboglabra were selected as surrogate plant species. Results indicated that I. aquatic and V. sinensis were the most tolerant plants to endosulfan-sulfate and heptachlor mixtures. These organochlorine mixtures did not affect percentage of seed germination, root length, shoot length, fresh weight and dry weight of these plants. Meanwhile, endosulfan-sulfate and heptachlor mixtures reduced root length of O. sativa var. glutinosa cv. RD6 but did not affect other growth pattern. B. alboglabra was the most sensitive plant species to endosulfan-sulfate and heptachlor mixtures. Only 0.4 mg/kg dried soil of endosulfan-sulfate and heptachlor mixtures signif icantly reduced percentage of seed germination, shoot length, seed vigor index and fresh weight of B. alboglabra (P<0.05)