Involvement of Foliar Absorption and Translocation in Differential Response between Bidens tripartita and B. frondosa to Bensulfuron Methyl

Abstract

Response of two Bidens species (B. tripartita and B. frondosa) to bensulfuron methyl (Methyl=α-(4, 6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-o-toluate) was compared and factors accounting for their differential response were investigated. A greenhouse experiment showed that B. tripartita had greater tolerance to the herbicide than B. frondosa, although the latter had moderate tolerance which was comparable to that of barnyardgrass (Echinochloa crusgalli). Absorption of ¹⁴C from aboveground (shoot) tissue following ¹⁴C-bensulfuron methyl application was more rapid in B. frondosa than in B. tripartita. Absorption from cotyledon was also much greater in B. frondosa and absorbed ¹⁴C was distributed throughout the shoots of the species. Differential foliar absorption and translocation between the Bidens species may partly explain their differential response to bensulfuron methyl.