Manitoba growers on alert for kochia

Till or hand weed | Glyphosate resistant kochia found in all three prairie provinces

Manitoba weed experts are stepping up efforts to control the spread of glyphosate resistant kochia now that it has officially arrived in the province.

Manitoba Agriculture announced in mid-April that it had found glyphosate resistant kochia in two fields in the province’s Red River Valley.

Ag reps found the glyphosate resistant kochia last fall during a weed survey of agricultural land in Manitoba but couldn’t confirm the finding until laboratory tests verified their suspicion.

Provincial weed specialist Nasir Shaikh said glyphosate resistant kochia has been found in Saskatchewan, North Dakota and Minnesota, so a Manitoba case was inevitable.

The Red River Valley discovery is peculiar because kochia is more prevalent in southwestern Manitoba.

“We have a lot of glyphosate resistant kochia just south of the border in North Dakota and Minnesota,” Shaikh said.

“There may be a chance it (the weed) moved with the flood waters, or moved from (there) up north.”

The glyphosate resistant weeds were found on a soybean field and a corn field in the Red River Valley.

The soybean producer applied glyphosate three times to the field during the growing season, but a number of kochia plants persisted, Shaikh said.

“When it (kochia) was not controlled, he was concerned and called up (Manitoba Agriculture).”

Shaikh and others will work with the affected growers and neigh-bouring landowners to limit the weed’s spread.

The soybean grower removed weeds by hand that showed signs of glyphosate resistance. Shaikh is encouraging other producers to do the same.

“Be very watchful,” he said.

“If you can identify it early in the season and if (a grower) suspects it may be glyphosate resistant kochia, then a (farmer) can go out and do some tillage or hand weeding.”

Shaikh plans to hold sessions this summer to educate growers about herbicide resistance and appropriate tactics, such as tank mixing and other aspects of integrated weed management.

Glyphosate resistant kochia is present in all three prairie provinces. Scientists first detected resistant kochia in southern Alberta in 2011 and near Swift Current, Sask., in 2012.

Kent Fraser, vice-president of Stratus Ag Research, said prairie farmers recognize that glyphosate resistance is a serious issue.

Stratus conducted an online poll of 802 western Canadian farmers in December to gauge the severity of the problem and farmer attitudes regarding glyphosate resistance.

“Even those who don’t have any glyphosate resistance … about 50 percent are concerned or very concerned about the problem,” Fraser said.

“The awareness and interest is there.”

But are they altering weed management strategies to mitigate herbicide resistance?

Weed scientists occasionally become frustrated because some growers rely solely on glyphosate and are unwilling to adopt more sophisticated tactics.

The Stratus survey suggests farmers are willing to take action to combat glyphosate resistant weeds.

The survey asked growers if they agree, disagree, strongly agree with 10 statements.

One of them was: “Me or my family will continue to farm this land for many years to come, therefore it is important to prevent resistant weeds.”

Fraser said nearly every farmer agreed with that statement.

“So, these (farmers) are good stewards.”

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