Imazamox in maize: Uptake, persistence and interference on protein and carbohydrate formation

Imazamox uptake and degradation were investigated in maize (Zea mays hybrid Balka) by means of an HPLC procedure standardized for this purpose. Herbic ide uptake increased during the first 24 h after treatment. Thereafter the degradation rate prevailed resulting in imazamox residues becoming negligib le 72 h after treatment. In spite of the rapid degradation of imazamox, dec reased amounts of valine, leucine and isoleucine as well as of total protei n were found in the treated samples. This is thought to be a direct consequ ence of imazamox action on its target site, acetohydroxyacid synthase. Also a decrease in starch which was counterbalanced by an increase in soluble s ugars was ascertained as a secondary effect of the herbicide action, Nevert heless, the above effects were produced at a sublethal level, without appar ent symptoms of stress.