Vapor Absorption and Translocation of Dinitroaniline Herbicides in Oats (Avena sativa) and Peas (Pisum sativum)

Roots or shoots of oats ( Avena sativa L. ‘Dal’) and peas ( Pisum sativum L. ‘Early Perfection’) were exposed to vapors of 14 C-labeled benefin ( N -butyl- N -ethyl-α,α,α-trifluoro-2,6-dinitro- p -toluidine), dinitramine ( N 4 , N 4 -diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine), fluchloralin [ N -(2-chloroethyl)-2,6 dinitro- N -propyl-4-(trifluoromethyl)aniline], oryzalin (3,5-dinitro- N 4 , N 4 -dipropylsulfanilamide), profluralin [ N -(cyclopropylmethyl)-α,α,α-trifluoro-2,6-dinitro- N -propyl- p -toluidine], and trifluralin (α,α,α-trifluoro-2,6-dinitro- N,N -dipropyl- p -toluidine). All of the dinitroaniline herbicides except oryzalin were absorbed by roots and shoots of germinating oats and peas. Some root-shoot translocation of the herbicides was observed in peas, but no shoot-root transport could be detected in either peas or oats. In peas, 14 C from root-absorbed benefin, fluchloralin, profluralin and trifluralin was detected in shoots, and 14 C from benefin and trifluralin was detected in cotyledons. In general, vapor absorption was correlated with rates of herbicide volatilization.