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

Abstract

Production of soyabeans ( Glycine max, L. Merr) in rotation with spring barley ( Hordeum vulgare L) in Prince Edward Island, Canada, has increased in recent 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 evaluate herbicide treatments that would provide adequate vetch control. In field studies on soyabeans, combinations of metribuzin and metolachlor gave 94–100% control of tufted vetch, whereas, combinations of bentazon with imazethapyr, or aciflurofen, or thifensulfuron did not provide control. Imazethapyr or thifensulfuron applied alone post-emergence did not control tufted vetch. In glasshouse studies, metribuzin gave complete control of tufted vetch and narrow-leaf vetch when used at 500 and 1000 g/ha. Combinations of metribuzin 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 thifensulfuron methyl/tribenuron methyl when used in combination with MCPA amine. When thifensulfuron methyl/tribenuron methyl was used in combination with 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 thifensulfuron methyl/tribenuron methyl, MCPA amine, 2,4-D amine, or by bromoxynil. Dicamba/2,4-D gave 92% control of narrowleaf vetch but was not effective on tufted vetch.