Some varieties of canola have been modified to be resistant to specific herbicides. These varieties allow farmers to treat fields with certain herbicides that would damage conventional canola. That means better weed control, less tillage, earlier seeding, higher yields and a cleaner crop at harvest.
How herbicide tolerance was achieved
There are three main groups of herbicide-tolerant canola. The Roundup Ready and Liberty Link varieties were produced using genetic modification (GM), and the Clearfield varieties were developed using a traditional plant breeding technique called mutagenesis.
The same canola oil
Although the plant is modified, the oil of herbicide-resistant varieties is identical to the oil of conventional canola. The oil itself contains no GM material.
The transgenic gene in Roundup Ready and Liberty Link InVigor varieties is a protein, and all protein is removed from canola oil during processing. Therefore, no GM material remains.
Benefits for the environment, farmers and the economy
Reports released in 2015, 2011, and 2001 show that herbicide-tolerant varieties have had a huge impact on the profitability and sustainability of the Canadian canola industry. There are substantial benefits for the environment, farmers and the Canadian economy as a whole:
By reducing the need to control weeds with tillage, these varieties help farmers take good care of their land. Less tillage means better soil structure and less risk of erosion. Since adopting herbicide-tolerant canola, 86% of producers say they have reduced soil erosion.
A study by Smyth et al. (2011) found that:
64% of producers use conservation tillage as their preferred form of weed control, compared to 11% in 1999.
Since adopting herbicide-tolerant canola, 85% of farmers experienced increased levels of moisture conservation and 86% report reduced soil erosion.
As farmers make fewer passes over the field with tillage equipment, they reduce greenhouse gas emissions and keep carbon in the soil.
Brookes and Barfoot (2015) found that in 2013, GMHT canola in Canada saved 1.1 billion kg (1.1 million tonnes) of carbon dioxide, arising from reduced fuel use and additional soil carbon storage, equivalent to removing nearly 500,000 cars from the roads.
Smyth et al. (2011) estimated one million tonnes of carbon is sequestered or no longer released each year thanks to the switch to zero and minimum tillage practices. The value of this carbon off-set is about $5 million.
Growers of these varieties also use less chemical for weed control.
How farmers benefit
An article by Brewin and Malla (2015) estimated the benefit of herbicide-tolerant canola varieties from 1996 to 2012 at $30 billion. A paper by Brookes and Barfoot (2015) found an average farm income benefit of $53/hectare ($21/acre) from 1996-2013 for GMHT canola in Canada.
A study by Gusta et. al (2011) showed:
Herbicide-tolerant canola generated $1.06-1.19 billion in annual net direct and indirect benefits for farmers over the 2005-07 period.
Herbicide-tolerant varieties offered new weed control options that allowed farmers to decrease tillage. Most producers now prefer zero or minimum tillage for weed control.
The 2001 report showed that herbicide-tolerant varieties increase the farmer’s net return by $5.80/acre. These varieties are more profitable because they increase revenues and reduce costs:
Average yields are 10% higher because of better-yielding varieties, earlier seeding and better weed control.
- The harvested crop has less dockage (such as weed seed and chaff in the harvested seed) so farmers get higher prices for their canola.
Farmers use less tillage, more direct-seeding and less summerfallow, which means big savings of time and fuel, and less wear and tear on equipment.
Less herbicide is used. One study showed that herbicide costs were about 40% lower for growers using GM versus conventional canola.
Because of these advantages, herbicide-tolerant varieties have quickly grown in popularity since their introduction in 1995. In 2010, 99% of canola acres in Canada were herbicide-tolerant varieties.
When the industry adopts progressive new technology, there are benefits to the entire Canadian economy. The introduction of GM canola and herbicide-tolerance has generated more investment in canola crushing plants and expansion of local agri-business as a whole. In 1997-2000 alone, the direct and indirect value of this activity was up to $464 million.
A 2015 paper by Smyth et al. summarizes the global benefits of GM crops, noting economic benefits accrue to adopting farmers, to innovators and to consumers, both in the country of adoption and more widely through trade.
What about “volunteer canola”?
When any type of crop has been grown on a field, some seeds are left behind at harvest. If they germinate the following year, they are called "volunteers." Research by Smyth et al. (2011) found that there has been no marked change in volunteer canola as a ‘weed’ as a result of the transition to GMHT systems.
A study conducted in 2001 and 2005 showed that managing GM volunteers is usually the same or easier than managing conventional volunteers. In a few cases, growers have found canola volunteers with multiple resistance to herbicide. However, these plants are easily controlled with other common herbicides.
GM canola has crossed with other types of canola, just as conventional canola would be expected to do. However, there are no cases of GM canola crossing with weeds in Canada.