INFLUENCE OF TEMPERATURE AND LIGHT-INTENSITY ON ABSORPTION, TRANSLOCATION, AND PHYTOTOXICITY OF FENOXAPROP-ETHYL AND IMAZAMETHABENZ-METHYL IN AVENA-FATUA

The absorption and translocation of fenoxaprop-ethyl and imazamethaben z-methyl were investigated in wild oat (Avena fatua L.) plants grown u nder different temperature and light intensity conditions by using C-1 4 tracer techniques. The phytotoxicity of both herbicides, applied as individual droplets, was also determined under similar environments. T he absorption of fenoxaprop-ethyl and imazamethabenz-methyl was increa sed by high temperature (30/20 degrees C) and to a lesser extent by 70 % shading; low temperature (10/5 degrees C) had limited effect on the absorption. The basipetal translocation of fenoxaprop-ethyl was not af fected by high temperature, and the increase in imazamethabenz-methyl translocation at high temperature was likely the result of the increas ed absorption. Low temperature decreased total translocation and trans location efficiency in both fenoxaprop-ethyl and imazamethabenz-methyl , Low light intensity tended to reduce the efficiency of basipetal tra nslocation of both herbicides. Fenoxaprop-ethyl phytotoxicity was redu ced by high temperature but not by low temperature. Temperature had li ttle effect on imazamethabenz-methyl effectiveness. Under 70% shading, the phytotoxicity of both herbicides was enhanced.