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 imazamethabenz-methyl were investigated in wild oat (Avena fatua L.) plants grown under different temperature and light intensity conditions by using ¹⁴C tracer techniques. The phytotoxicity of both herbicides, applied as individual droplets, was also determined under similar environments. The absorption of fenoxaprop-ethyl and imazamethabenz-methyl was increased by high temperature (30/20°C) and to a lesser extent by 70% shading; low temperature (10/5°C) had limited effect on the absorption. The basipetal translocation of fenoxaprop-ethyl was not affected by high temperature, and the increase in imazamethabenz-methyl translocation at high temperature was likely the result of the increased absorption. Low temperature decreased total translocation and translocation efficiency in both fenoxaprop-ethyl and imazamethabenz-methyl. Low light intensity tended to reduce the efficiency of basipetal translocation of both herbicides. Fenoxaprop-ethyl phytotoxicity was reduced by high temperature but not by low temperature. Temperature had little effect on imazamethabenz-methyl effectiveness. Under 70% shading, the phytotoxicity of both herbicides was enhanced.Abbreviation S.E.D. standard errors of difference