Three field experiments were conducted in 1987 through 1989 to evaluat
e hogpotato control and rotational crop response resulting from applic
ations of five herbicides. At the end of the first year, triclopyr and
imazapyr controlled hogpotato late-season as high as 87 and 94%, resp
ectively. Following a sequential application in 1988, triclopyr and im
azapyr controlled 94 and 100% of hogpotato, respectively, during the 1
989 growing season. Hogpotato biomass, collected at the termination of
the experiments, was reduced by all treatments at all locations excep
t at Altus where dicamba was applied in 1987 followed by a spot applic
ation of glyphosate in 1988. Soils from these experiments were bioassa
yed for residual herbicide activity using three potential rotational c
rop species. Tebuthiuron and imazapyr caused the greatest biomass redu
ctions with cotton and wheat being the most sensitive species to these
herbicides.