Evaluation of Postemergence Herbicide Combinations for Long-Term Trumpetcreeper (Campsis radicans) Control in Corn (Zea mays)1

Field trials were conducted in Virginia during 2000 and 2001 to evaluate long-term trumpetcreeper control in corn with dicamba, BAS 654 plus dicamba, 2,4-D, CGA 152005 plus primisulfuron, halosulfuron, primisulfuron, and mesotrione. Each of these herbicides was applied alone as a single postemergence (POST) treatment or as a component of a POST herbicide combination. Trumpetcreeper suppression ratings 3 mo after treatment (MAT) revealed a general trend toward higher levels of suppression with combinations of dicamba, BAS 654 plus dicamba, or 2,4-D with any of the sulfonylurea herbicides and lower levels of suppression with applications of any of the sulfonylurea herbicides alone. Combinations of dicamba, BAS 654 plus dicamba, or 2,4-D with mesotrione also provided some of the highest levels of trumpetcreeper suppression 3 MAT in both years. At 1 yr after treatment (YAT), 2,4-D alone, BAS 654 plus dicamba, CGA 152005 plus primisulfuron plus 280 g ai/ha dicamba, primisulfuron plus 280 g/ha dicamba, primisulfuron plus 2,4-D, mesotrione plus BAS 654 plus dicamba, and mesotrione plus 2,4-D reduced trumpetcreeper stem density by at least 52%% when compared with that of the nontreated control. These herbicide treatments were the only ones that provided reductions in trumpetcreeper stem density 1 YAT when compared with that of the nontreated control. In 2000 and 2001, there were few differences in corn yield among the treatments evaluated in these trials, and no treatment resulted in corn yields that were lower than the nontreated control. Acceptable trumpetcreeper suppression may be achieved during the season of treatment with any of these herbicide combinations, but only a few treatments will provide long-term trumpetcreeper control.Nomenclature: BAS 654, 2-(1-[[([[3, 5-difluorophenylamino]]carbonyl)-hydrazono]]ethyl)-3-pyridine-carboxylic acid, proposed common name diflufenzopyr; CGA 152005, 1-(4-methoxy-6-methyl-triazin-2-yl)-3-[[2-(3, 3, 3-trifluoropropyl)-phenylsulfonyl]]-urea, proposed common name prosulfuron; dicamba; 2,4-D dimethylamine salt; halosulfuron; mesotrione; primisulfuron; trumpetcreeper, Campsis radicans (L.) Seem. ex Bureau ##³ CMIRA; corn, Zea mays L.Additional index words: Growth regulator herbicides, no-till, herbicide combinations, perennial weed control, sulfonylurea herbicides.Abbreviations: MAT, months after treatment; POST, postemergence; YAT, years after treatment.