Plant Science Post

Q&A: Why Canada’s Farmers Choose Herbicide-Tolerant Canola

December 4, 2014
Soil

Ever since it was developed in 1995, herbicide-tolerant canola has quickly grown in popularity and today it is farmed on 99 percent of canola acres in Canada. We spoke to Dr. Curtis Rempel, Vice President of Crop Production & Innovation for the Canola Council of Canada, to find out why herbicide-tolerant canola is so popular there.

What is herbicide-tolerant canola?

It’s a variety of canola that can withstand the application of herbicide after the seed has sprouted. Before herbicide-tolerant canola was developed, farmers would work herbicides into the soil in the spring and attempt to control weeds before planting their seeds.

When was it developed?

The very first herbicide-tolerant canola was developed at the University of Guelph in Ontario, Canada in the 1980s. It was resistant to herbicides containing the active ingredient triazine. Today, most farmers grow canola varieties that are resistant to herbicides with the active ingredient glyphosate or glufosinate. These varieties were developed in the mid-1990s and were sold to farmers for planting in 1997. They allowed farmers to spray their crop with herbicide after the canola has sprouted.

How does it affect the soil and the environment?

There are a number of environmental and soil benefits that go along with herbicide-tolerant canola.

First, there is greater biodiversity. Glyphosate and glufosinate will control weeds with reduced impact on other living things. As a result, more insects are thriving in farmland soil and their activity is supporting healthy crop development. For example, earthworms break down dirt clods and organic matter into soil that is well-aerated and rich in the nutrients that plants need.

Second, there is less erosion. Now that farmers can spray herbicide on their crop to control weeds, they no longer need to till their soil. This has helped keep moisture and organic matter in the soil, which makes it less susceptible to water and wind erosion. Throughout the 20th century, it was common to see soil blown up against fence posts and into ditches during wind storms. You simply don’t see that in Canada any more.

And third, there is more moisture retention. With less tillage and more organic matter, soil is able to hold more moisture. This helps prevent runoff – crop inputs like fertilizer are staying on the fields where they are needed. Crops are also able to withstand periods of drought when grown in soil with strong moisture retention.

How does it benefit Canada’s farmers?

The biggest benefit to farmers is more yield. They no longer have to till their fields in the spring to control weeds, so they can plant their canola seed earlier and give it more time to reach its full yield potential. Farmers can also control a greater variety of weeds, so when they harvest their canola in the fall, there are fewer weed seeds in their production – this allows the farmer to earn a better price at the grain elevator.

Farmers also save time and fuel by growing herbicide-tolerant canola. They used to spend a lot of time tilling their fields. Now that they can use herbicide to control weeds, farmers burn less fuel working the soil with tillage equipment.

Will consumers taste the difference?

No, you can’t taste the difference between oil crushed from herbicide-tolerant canola and that crushed from conventional canola. When the herbicide-tolerant plant was still growing, its DNA produced a protein (specifically an enzyme) that broke down the herbicide to make it non-toxic for the plant. That protein doesn’t end up in canola oil.

To read more about herbicide-tolerant canola, visit http://www.canolacouncil.org/oil-and-meal/canola-innovation/herbicide-tolerant-canola