Published online by Cambridge University Press: 12 June 2017
The absorption and translocation of 14C-terbutryn [2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine] and 14C-fluometuron [1,1-dimethyl-3-(α,α,α,-trifluoro-m-tolyl) urea] in cotton (Gossypium hirsutum L. ‘SJ-1′) and snapbean (Phaseolus vulgaris L. ‘Tenderette’) were studied. 14C-terbutryn supplied to the roots accumulated in the root system of both species. However, snapbean plants (sensitive) absorbed and translocated more 14C to the shoots than cotton (tolerant), followed by rapid distribution in the leaf mesophyll tissue. In cotton, the translocated 14C-terbutryn accumulated in stems, petioles, and leaf veins. Excised cotton roots absorbed more 14C-terbutryn than excised snapbean roots. The uptake and distribution pattern of root-applied 14C-fluometuron was similar in both species. Foliar application to the primary leaf of snapbeans and to one cotyledon of cotton resulted in 2% of 14C-terbutryn transported acropetally to younger leaves with no basipetal movement. Translocation of 14C-fluometuron from the site of foliar application was two or three times faster than terbutryn with significant basipetal transport in both species.