Uptake and Translocation of Foliarly-Applied Atrazine

Abstract

Uptake of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) as influenced by adjuvants to the treatment medium was studied using both excised leaf sections and leaves of intact plants. Uptake of the14C-atrazine label by yellow foxtail(Setaria glauca(L.) Beauv.) leaf sections was higher at 35 than at 5 C and at pH 3 and 9 than at 5 or 7. The rapid uptake of14C-atrazine label by corn(Zea maysL.) leaf sections was attributed to a high rate of atrazine metabolism. However, atrazine metabolism did not explain the greater uptake by common lambsquarters(Chenopodium albumL.) leaf sections than by yellow foxtail. Atrazine14C-label uptake by yellow foxtail leaf sections from exogenous solution was influenced by light, phospholipase D or water pretreatment, atrazine concentration, and oil. The14C-label of atrazine in the leaf distal to the treated spot was greater when the treatment contained an oil than when applied in only water even though the area of the spot was kept constant. Further, greater uptake of the label occurred at a high than at a low temperature regardless of the application medium.