Influence of Bentazon on Absorption and Translocation of Sethoxydim in Goosegrass (Eleusine indica)

Abstract

The absorption and translocation of sethoxydim {2[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} as influenced by bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] were studied in goosegrass [Eleusine indica(L.) Gaertn. ♯3ELEIN]. The presence of bentazon in the treatment emulsion decreased foliar absorption of14C applied as14C-sethoxydim by about half. Significantly less14C was found in the treated leaf, shoot tissue above the treated leaf, shoot tissue below the treated leaf, and roots of plants treated with a mixture of14C-sethoxydim and bentazon than with14C-sethoxydim alone. After 6 h, 3.5% of applied14C was recovered from plant parts other than the treated leaf in the absence of bentazon, compared to 1.1% of that applied in combination with bentazon. The difference in foliar absorption between the two treatments may account for the antagonistic interaction between these herbicides observed in the field.