~ This week’s blog is brought to you by Dwight Willoughby P.Ag, CCSC
In our farming area we have been long aware of resistant weeds. In RR corn, glyphosate is the foundation of your weed control but, it should not be relied upon to do all the heavy lifting. We know what the consequences would be of losing such a valuable herbicide to resistance and we need to manage to avoid that. A few years ago, popular wisdom was to just rotate different modes of action with our crop rotations to delay the onset of resistance. Today, with the ever expanding RR crops and acres, weed scientists now recommend an integrated approach of rotating modes of action and employing tank mix options with different modes of action with our corn rotations.
Recently, research has indicated that tank-mixes are potentially more effective then rotation in delaying the development of herbicide resistance. What’s important to note is to be prudent and chose tank mix partners from 2 different modes of action groups that overlap on the target weed in question.
The Western Canadian experience of glyphosate resistance weeds is relatively new, but we need to be scouting for weeds that have a history of glyphosate resistance in neighbouring provinces and states such as; kochia, fleabane, volunteer canola, Russian thistle, tall waterhemp, common and giant ragweed plus annual sow thistle.
Suggested Tank Mixes
Pre-seed and Pre-ground crack burn-off
Mode of Action Weeds
Heat LQ 14 – Kochia, giant ragweed, common ragweed, annual sow thistle, Russian thistle, volunteer canola.
Armezon 26 – Giant ragweed, kochia, suppression of common ragweed, volunteer canola
Basagran 6 – Volunteer canola, suppression of kochia