Translocation of Dipropetryn and Prometryn in Seedlings and Excised Leaves of Oats(Avena sativa)and Corn(Zea mays)

Abstract

The absorption of14C-dipropetryn (2-ethylthio-4,6-bis-isopropylamine-s-triazine) and14C-prometryn [2,4-bis(isopropylamino)-6-(methylthio)-s-triazine] by roots of intact seedlings of corn(Zea maysL. ‘Iowa Chief) and oats(Avena sativaL. ‘Cimarron’) was very extensive and occurred to about the same degree in both species after application to the root medium. The translocation of14C-label of dipropetryn to the shoots was low in corn as compared to oats. Prometryn14C-label was more readily translocated to the tops of corn than dipropetryn and was more readily translocated in oats than corn. Dipropetryn14C-label entered excised leaves through the transpiration stream during a short exposure period and translocated to a greater extent in oats than in corn. The14C-label of dipropetryn became immobilized in excised leaves after about 4 h. The14C-label of prometryn was initially more mobile in excised leaves of oats than corn. However, translocation of the14C-label of prometryn continued in both species during 10 h of treatment and there was very little difference in the final distribution pattern. DNP (2,4-dinitrophenol) did not affect the distribution pattern of the14C-label of dipropetryn or prometryn in corn after 10 h treatments.