Extra care urged when applying fall glyphosate

Producers are warned that herbicide residues detected in overseas shipments could potentially disrupt international export market

Crop specialists say farmers should be more mindful if applying pre-harvest glyphosate this fall, given many fields have uneven levels of maturity.

They say producers will have to make sure all crops reach their maturity level before applying. If they apply too early, residues could end up in kernels and potentially jeopardize markets.

“Consumers around the world are paying more attention to glyphosate, which means there is an increased focus from end users,” said Jeremy Boychyn, an agronomy research extension specialist with the Alberta wheat and barley commissions.

“It’s important for us as an export country to make sure we are taking proper steps to minimize residue risk.”

He encouraged farmers to follow a number of steps before applying the herbicide.

He said if farmers are using it as weed control, they should go to the least-advanced part of the field to check maturity on the least-advanced part of the crop, like low-lying acres or tillers.

If the tillers will make it into the combine, farmers should look at the part of the stem that is below the wheat head. When it begins to yellow, it’s beginning to mature.

The true test, however, is squishing a kernel with the thumbnail.

He said if the thumbnail indent in the kernel remains intact, the crop is mature. Seed moisture must be less than 30 percent when pre-harvest glyphosate is applied.

“That indent needs to stay in,” Boychyn said. “If it pushes back out it’s not there yet.”

The tips are part of the Keep-it-Clean awareness campaign, an effort by crop groups to educate producers on clean practices so they can avoid market access issues.

But it might be tricky for some farmers this year to decide how they are going to approach harvest.

They might not have enough time to wait for all crops to mature before applying glyphosate, instead choosing to swath before freezing temperatures set in. The herbicide wouldn’t have to be applied if the crop is swathed.

If they swath, however, and later face wet conditions, the crop could sprout and deteriorate. It would be worse off than if it endured a frost.

“It’s quite the conundrum,” said Neil Whatley, a crop specialist with Alberta Agriculture. “Farming is like going to Vegas. It’s just a big gamble sometimes.”

Before applying a herbicide, Whatley recommended farmers speak with their buyers if they are unsure.

He said speaking with them about a crop’s maximum residue limits (MRL) will ensure everyone is on the same page, noting market access concerns are important to consider.

“Other end-users, especially those purchasing barley for the malt market, or oat millers, have their own MRL regulations or do not allow pre-harvest herbicides to be used at all,” he said. “Barley for livestock feed is not as serious.”

Boychyn said it’s important to understand the value of international markets and believes most producers are taking steps to protect them.

“I think it’s making sure we are consistent in understanding the value of those markets,” he said. “What we do can have an impact, even if it’s just one quarter section.”

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