EFFECT OF HERBICIDES ON THE TOXICITY OF FUNGICIDES AGAINST RHIZOCTONIA-SOLANI CAUSING DAMPING-OFF OF COTTON

The effect of two herbicides (paraquat and simazine on the antifungal activity of two fungicides (captan and mounsrin) against Rhizoctonia s olani was studied. when the herbicides paraquat and simazine were appl ied to soil they altered the effectiveness of both fungicides in contr olling R. solani, thus causing damping-off of cotton. Both herbicides increased the toxicity of both fungicides against mycelial growth of t he fungus. In pot tests, seeds or soil treated with captan or mounsrin gave better control of R. solani damping-off disease when the soil wa s treated with paraquat or simazine compared to untreated soil. Captan was, however, found to be more effective in controlling the disease t han mounsrin.