Mountain View and Red Deer county farmers are being encouraged to be on the lookout for herbicide resistant weeds in their fields this spring.
Field scouting, where the producer looks for weeds that have emerged even though herbicides have been applied, is one of the best ways to identify the unwanted plants, say officials.
“Although herbicide resistant weeds have been found in Alberta, they aren't having a major impact on producers in Mountain View County,” said Jane Fulton, agriculture services manager at MVC.
“Many (producers) are employing weed control best management practices to avoid the increasing threat of resistance and are applying an integrated weed management approach.”
Provincewide several weeds have already been confirmed herbicide resistant, including wild oats, chickweed, cleavers and kochia.
When trying to identify herbicide resistant weeds, there are several things to watch for, she said.
“Do some individual plants of the same weed species show herbicide injury symptoms next to others, of the same weed species, with no visible symptoms? As well, examine your herbicide application logs. Is the same herbicide group being applied year after year?” she said.
“If you suspect you have herbicide resistant weeds first rule out all other factors. For example, review the herbicide label, to ensure the suspected weed species is listed. Could there have been a missed application or environmental factors?
“Another indication that herbicide resistance may not be the issue, is if there are multiple species of weeds that were not controlled.”
Alberta Agriculture recently put out the call for farmers to scout their fields and look for herbicide resistant weeds.
“When herbicides are used effectively, weed competition will be reduced resulting in a crop yield benefit and in order to ensure a successful herbicide application there are a number of decisions that need to be made by the producer,” Mark Cutts, crop specialist, said in an Alberta Agriculture news release.
“An increasing concern in many areas of annual crop production is the resistance of weed species to herbicides. In certain situations field scouting may determine that weed control was not achieved.
“When this situation is recognized, producers can start to evaluate what might have caused the poor control such as environmental conditions or the possibility of herbicide resistant weeds being present.”
There are a number of ways to combat the problem of herbicide resistant weeds.
“Weed resistance can be delayed by rotating herbicide groups, using a herbicide with more than one mode of action, and crop rotation,” said Fulton. “Other cultural methods can be applied if herbicide resistance is of concern.”
If you suspect weed resistance, collect and send the weed and seed samples to a lab for testing and confirmation, she said.
For more information or assistance call Mountain View County Agricultural Services at 403-335-3311 or Alberta Agriculture and Rural Development at 310-FARM, she said.
"Many (producers) are employing weed control best management practices to avoid the increasing threat of resistance."Jane Fultonagricultural services manager
