Field studies were conducted from 2003 through 2006 to evaluate bundleflower tolerance to several postemergence (POST) herbicides commonly used in pastures. All herbicides except imazapic, metsulfuron, and 2,4-DB injured bundleflower at least 88% when rated 4 wk after treatment (WAT). When rated 8 WAT, metsulfuron, picloram, and picloram plus 2,4-D injured bundleflower greater than 90%. Imazapic stunted bundleflower (10 to 35% injury) throughout the growing season. When rated 52 WAT, dicamba plus 2,4-D, picloram alone, and picloram plus 2,4-D injured bundleflower at least 97% in one of two years. Emergence of bundleflower with picloram-containing treatments ranged from 16 to 67% of the nontreated control, whereas emergence after dicamba-containing treatments ranged from 67 to 97%.
Nomenclature: Dicamba; glyphosate; imazapic; metsulfuron; picloram; 2,4-D; bundleflower, Desmanthus bicornutus S. Watson ‘BeeTAM-06’, ‘BeeTAM-08’, ‘BeeTAM-37’, ‘BeeTAM-57’.