Agriculture, Aquaculture and Fisheries - Evaluation of Herbicides for Hempnettle and Chickweed Control in Barley

Abstract: Hempnettle (Galeopsis tetrahit) and common chickweed (Stellaria media) can cause significant production issues in grain production in New Brunswick. Both weeds can escape conventional control measures, such as MCPA amine, and cause yield reductions within a barley (Hordeum vulgare) crop. A trial was established in a commercial barley field near Saint Basile, New Brunswick to evaluate herbicide control options. Thifensulfuron/tribenuron–methyl, pyrasulfotole/bromoxynil, fluroxypyr/MCPA and florasulam/fluroxypyr/MCPA were the most effective herbicides tested for both hemp–nettle and common chickweed. The other products tested only suppressed hemp–nettle populations and were not effective for chickweed. Delaying MCPA application can decrease the level of weed control, especially for hard to control weed species like hemp–nettle. Fluroxypyr mixes were highly effective for both weed species and these mixes should be considered for potential registration.