Effect of fentrazamide on the growth, morphology and anatomy of Echinochloa crus-galli and Echinochloa oryzicola

The effects of fentrazamide [4-(2-chlorophenyl)-N-cyclohexyl-N-ethyl-4,5-dihydro-5-oxo-1H-tetrazole-1-carboxamide] on the growth and morphology of Echinochloa crus-galli (L.) Beav. and Echinochloa oryzicola Vasing. were investigated. Fentrazamide at 250g a.i./ha showed high efficacy on weeds up to the 3-leaf stage. The growth of the subsequent leaves was retarded by the herbicide and dark green coloration appeared, and then the basal part of leaf sheathes underwent necrosis. The cell elongation and cell division of Echinochloa spp. were inhibited by fentrazamide. These effects were also observed on plants treated with mefenacet [2-(2-benzothiazoyloxy)-N- methyl-N-phenyl-acetamide].