Absorption and Translocation of Terbutryn and Fluometuron in Cotton (Gossypium hirsutum) and Snapbeans (Phaseolus vulgaris)

Abstract

The absorption and translocation of14C-terbutryn [2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine] and14C-fluometuron [1,1-dimethyl-3-(α,α,α,-trifluoro-m-tolyl) urea] in cotton (Gossypium hirsutumL. ‘SJ-1′) and snapbean (Phaseolus vulgarisL. ‘Tenderette’) were studied.14C-terbutryn supplied to the roots accumulated in the root system of both species. However, snapbean plants (sensitive) absorbed and translocated more14C to the shoots than cotton (tolerant), followed by rapid distribution in the leaf mesophyll tissue. In cotton, the translocated14C-terbutryn accumulated in stems, petioles, and leaf veins. Excised cotton roots absorbed more14C-terbutryn than excised snapbean roots. The uptake and distribution pattern of root-applied14C-fluometuron was similar in both species. Foliar application to the primary leaf of snapbeans and to one cotyledon of cotton resulted in 2% of14C-terbutryn transported acropetally to younger leaves with no basipetal movement. Translocation of14C-fluometuron from the site of foliar application was two or three times faster than terbutryn with significant basipetal transport in both species.