In velvetleaf (Abutilon theophrasti Medic. ♯3 ABUTH), accelerated leaf abscission was a conspicuous response following foliar chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl] benzenesulfonamide} treatment at 35 g ai/ha. Leaf abscission of treated plants was decreased by AVG [L-2-amino-4-(2-aminoethoxy)-trans-3-butenoic acid], an inhibitor of endogenous ethylene production. Chlorsulfuron stimulated ethylene production in the abscission zone and leaves of treated plants and also increased cellulase activity in the abscission zone. Accelerated leaf abscission of velvetleaf following chlorsulfuron application appears to result from chlorsulfuron-induced increases in endogenous ethylene production and cellulase activity.
