HOGPOTATO (HOFFMANSEGGIA-GLAUCA) CONTROL WITH HERBICIDES AND ROTATIONAL CROP RESPONSE

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.