Effect of Diallate on Foliar Uptake and Translocation of Herbicides in Pea

Abstract

Exposure of pea plants (Pisum sativumL. ‘Little Marvel’) to vapors ofS-(2,3-dichloroallyl)diisopropylthiocarbamate (diallate) increased the subsequent foliar uptake of14C-labeled herbicides. Increased amounts of14C-activity were found in the tissues of diallate-treated plants as compared to the controls when herbicides were applied to the leaves as aqueous solutions or embedded in agar blocks. The herbicides were (2,4-dichlorophenoxy)acetic acid-1-14C (2,4-D), uniformly ring-14C 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine),trichloroacetic acid-2-14C (TCA), and ethylene-14C 6,7-dihydrodipyrido[1,2-a:2′,1′-c]pyrazinediium ion (diquat). The increased movement of herbicides into diallate-treated peas was primarily attributed to a reduction of epicuticular lipids on leaves of the treated plants.