Adjuvants influence weed control and crop tolerance provided by postemergen
ce (POST) herbicides. Adjuvant effects on weed control and corn and soybean
tolerance with CGA-248757 and flumiclorac applied alone and soybean tolera
nce with CGA-248757 and flumiclorac applied in combination with imazethapyr
or CGA-277476 were evaluated. Velvetleaf control in the greenhouse and com
mon lambsquarters, redroot pigweed, and common ragweed control in the green
house and field with CGA-248757 and flumiclorac were increased by the addit
ion of an adjuvant. However, corn and soybean tolerance to these herbicides
was not affected by adding an adjuvant. Laboratory studies suggest enhance
d weed control from the addition of an adjuvant resulted from an increase i
n CGA-248757 and flumiclorac foliar absorption. In greenhouse studies, velv
etleaf, common lambsquarters, and redroot pigweed control with CGA-248757 p
lus imazethapyr; velvetleaf control with flumiclorac plus imazethapyr; redr
oot pigweed and common ragweed control with CGA-248757 plus CGA-277476; and
velvetleaf, redroot pigweed, and common ragweed control with flumiclorac p
lus CGA-277476 increased by adding an organosilicone adjuvant when compared
with adding a nonionic surfactant (NIS). However, in field evaluations of
CGA-248757 or flumiclorac plus imazethapyr, the addition of NIS or an organ
osilicone adjuvant resulted in equivalent soybean injury, common lambsquart
ers and redroot pigweed control, and soybean yield. Yet in tank mixtures of
CGA-248757 or flumiclorac plus CGA-277476, the addition of an organosilico
ne adjuvant increased redroot pigweed control and soybean yield compared to
adding NIS.