Evaluation of herbicides for control of tufted vetch (Vicia cracca) and narrow-leaved vetch (Vicia angustifolia)

Production of soyabeans (Glycine mar, L. Merr) in rotation with spring barl ey (Hordeum vulgare L) in Prince Edward Island, Canada, has increased in re cent years and in fields used for several years tufted vetch (Vicia cracca L.) and narrow-leaved vetch (Vicia angustifolia Reichard) have become more of a problem. Experiments were conducted in the field and glasshouse to eva luate herbicide treatments that would provide adequate vetch control. In fi eld studies on soyabeans, combinations of metribuzin and metolachlor gave 9 4-100% control of tufted vetch, whereas, combinations of bentazon with imaz ethapyr, or aciflurofen, or thifensulfuron did not provide control. Imazeth apyr or thifensulfuron applied alone post-emergence did not control tufted vetch. In glasshouse studies, metribuzin gave complete control of tufted ve tch and narrow-leaf vetch when used at 500 and 1000 g/ha. Combinations of m etribuzin and metolachlor at lower rates controlled tufted vetch and narrow -leaf vetch. In glasshouse studies using herbicides normally used in barley , tufted vetch and narrow-leaf vetch were controlled by the herbicides thif ensulfuron methyl/tribenuron methyl when used in combination with MCPA amin e. When thifensulfuron methyl/tribenuron methyl was used in combination wit h 2,4-D amine control of narrow-leaf vetch was less than that achieved with tufted vetch. Tufted vetch and narrow-leaf vetch were not controlled by th ifensulfuron methyl/tribenuron methyl, MCPA amine, 2,4-D amine, or by bromo xynil. Dicamba/2,4-D gave 92% control of narrowleaf vetch but was not effec tive on tufted vetch. (C) 2001 Elsevier Science Ltd. All rights reserved.