Field and greenhouse studies were conducted to evaluate mesotrione alone and in combinations with low rates of atrazine and bentazon for control of yellow and purple nutsedge. Mesotrione alone at rates of 105 to 210 g ai/ha controlled yellow nutsedge 43 to 70%. Mixtures of mesotrione with atrazine at 280 g ai/ha did not always improve yellow nutsedge control over that by mesotrione alone, but increasing atrazine to 560 g ai/ha in these mixtures generally provided more consistent control of yellow nutsedge. Mesotrione at 105 g ai/ha mixed with bentazon at 280 or 560 g ai/ha controlled yellow nutsedge 88% or greater which was similar to control from the standard halosulfuron at 36 g ai/ha. Mesotrione, atrazine, and bentazon alone did not control purple nutsedge. Mixtures of mesotrione plus bentazon, however, did improve control of purple nutsedge over either herbicide applied alone, but this control was not considered commercially acceptable.
