Top Crop Manager

Features Herbicides Seed & Chemical
Triallate is still a good option in Western Canada

It has come to Top Crop Manager's attention through comments from some attendees that there may have been a misinterpretation of comments related to triallate at the Herbicide Resistance Summit held on March 2nd in Saskatoon.

Since the Summit, we have reviewed the most recent herbicide resistance survey from 2007-2009 and have noted the following: eight per cent of fields in Western Canada (15 per cent of fields in Alberta, three per cent of fields in Saskatchewan and 11 per cent of fields in Manitoba) had some resistance to Group 8 herbicides, triallate's mode of action group.

Research by Hugh J. Beckie and Sakti Jana (CJPS 2000, 80: 665-667) has shown that after long term use (18 years) of triallate, resistance had developed under continuous wheat production. This explains the higher percentage of fields in central Alberta showing Group 8 resistance, where triallate had been relied upon for years in wheat-barley rotations before post-emergence Group 1 and 2 herbicides came to the market. Gowan Canada is cognizant of triallate being a medium risk herbicide in regards to resistance development and asks growers to not use the product on more than 20-25 per cent of their acres each year.

Outside of fields that have had historical overuse of triallate, it is important to clarify to growers in search of a more diversified approach to wild oat management that they consider triallate based products. A key message from the Summit was that diversity in modes of action is key for managing and reducing the risk of weed resistance, and the same holds true for wild oats. Western Canadian growers will benefit from increased diversity, whether that be non-herbicidal management tools or ensuring they use all modes of action for wild oat control.

Top Crop Manager wants to ensure all Herbicide Resistance Summit delegates know that for most western Canadian growers, triallate is a valuable component of the entire suite of tools available to them in their battle against herbicide resistance.