Get the jump on resistant weeds

‘Learn from our mistakes,” says Ford Baldwin, of Practical Weed Consultants, Austin, Ark. “You can avoid all this.”

“All this” is glyphosate-resistant pigweeds. Some soybean fields in the Mid-South last year were a total loss, and had to be disked down and replanted. Others had to be rotated out of soybeans. Hand labor is routinely being used again in many cotton and soybean fields. The spread of resistant pigweed is affecting land rents. It may soon affect land values, he says.

Even if you have clean fields now, start managing like you have resistant weeds, advises Ford, who was a keynote speaker at a meeting earlier this year sponsored by Peterson Farms Seed, Harwood, N.D., and Bayer CropScience, a company which manufacturers Liberty and Ignite herbicides, which are alternatives to glyphosate.

Key Points

It’s best to manage for resistant weeds before you get them.

You’ll save money in the long run by changing products.

Use glyphosate where you don’t have other good options.

Resistant weed species can spread quickly from a few surviving plants in a field one year, to a few patches the next year, to an infestation that covers the whole field the third year.

The solution, says Baldwin, is to stop applying glyphosate year after year on the same field.

Glyphosate may only cost $3 to $5 per acre, but it won’t work forever if you are using it repeatedly on resistant crops, he says.

There’s already glyphosate-resistant ragweed and waterhemp in the region. Michael Christoffers, North Dakota State University assistant weed science professor, says he suspects there are resistant lambsquarters and kochia, too.

Save glyphosate for the crop you need it in the most — sugarbeets, soybeans or canola, for instance — Baldwin advises. There is plenty of other “firepower” to use in corn or wheat, he says. You also could try LibertyLink corn or soybeans.

Bottom line: Spend extra money on some of your acres now by using alternatives to glyphosate or by selecting herbicides to tank mix with glyphosate. It will save you money on all of your cropland in the future.


SMART SPRAYING: Paying a little more now on some of your acres to prevent resistant weed populations from developing will save you a lot of money on all of your acres in the future.

This article published in the March, 2011 edition of DAKOTA FARMER.

All rights reserved. Copyright Farm Progress Cos. 2011.