Abstract
The effect of four commonly used pesticides, Furadan (carbofuran, 3%), Sevin (carbaryl, 50%), Rogor (dimethoate, 30% EC) and Endotaf (endosulfan, 35% EC) on the blue-green algae of rice field soils was examined. The organochlorine, Endotaf, was found to be more toxic than the organophosphate, Rogor, and the carbamate pesticides, Sevin and Furadan, in the sequence. Lyngbya major, Gloeocapsa atrata, Calothrix parietina and Scytonema pascheri, all of which have well-defined sheaths, occurred in the soil in the presence of 1000, 500 and 250 ppm of the carbamate, organophosphate and organochlorine pesticides, respectively, where other blue-green algal forms could not survive.
