PEROXIDIZING PHYTOTOXIC ACTIVITY OF THIADIAZOLIDINE AND TRIAZOLIDINE COMPOUNDS

Using Scenedesmus acutus and Echinochloa utilis, a series of isomeric compounds, namely thiadiazolidines and triazolidines, were assayed wit h respect to decrease of chlorophyll contents, protoporphyrin-IX accum ulation, light-induced ethane formation levels. The both types of phyt otoxic compounds decreased chlorophyll contents, caused protoporphyrin -IX accumulation and ethane evolution, and inhibited growth of Scenede smus cells, just like the so-called peroxidizing herbicides such as p- nitrodiphenyl ethers and cyclic imides. Correlations between the phyto toxic parameters were highly significant. Our comparative data on diff erent sets of the parameters suggest that both the thiadiazolidine and triazolidine herbicides are classified as peroxidizing herbicides, af fecting a crucial enzyme in the chlorophyll biosynthesis and inducing ethane formation by the light induced radicals.