EFFECT OF MCPA AND FENOXAPROP ON PHYTOTOXICITY, RETENTION, FOLIAR UPTAKE AND TRANSLOCATION OF IMAZAMETHABENZ IN WILD OAT

The addition of MCPA (amine and ester) or fenoxaprop to imazamethabenz affected its phytotoxicity, retention and uptake and translocation in wild oat. MCPA amine and fenoxaprop, but not MCPA ester, antagonized the activity of imazamethabenz on wild oat. MCPA ester or fenoxaprop d ecreased, but MCPA amine had no effect on retention of imazamethabenz by wild oat foliage. Addition of MCPA ester increased absorption and a cropetal translocation but decreased basipetal translocation of C-14-i mazamethabenz. Addition of MCPA amine had no effect on absorption, but decreased acropetal and basipetal translocation of(14)C-imazamethaben z. Fenoxaprop increased absorption and acropetal translocation, but de creased basipetal translocation of C-14-imazamethabenz. Changes in abs orption, translocation, or retention accounted for all observed change s in phytotoxicity.