Canada’s corn growers are “slipping significantly” in following the requirements for a non-Bt refuge when planting Bt corn, a pest management stakeholders’ group says.
The Canadian Corn Pest Coalition, which includes academics, extension and research staff, regulators, corn growers’ associations and the seed industry, warned last week that refuge compliance dropped to 61 per cent in 2009 from highs of up to 80 per cent in 2005.
“We call on the corn industry across Canada to do the right thing and promote the planting of a proper refuge to minimize the risk of insects developing resistance,” coalition chairman Art Schaafsma of the University of Guelph said in the group’s release.
Refuge requirements for insect-tolerant crops such as Bt corn are meant to encourage low levels of survival among insect pests, preventing the pest population from developing resistance by diluting any resistant traits some insects may carry.
LOSS IN ACCESS
Varieties of Monsanto’s Bt corn brand, YieldGard, currently require a minimum of 20 per cent of a farmer’s total corn acreage to be planted to non-Bt refuge varieties.
In light of the concerns, Monsanto has implemented a new compliance policy to ensure farmers abide by the refuge guidelines. Farmers found to be non-compliant during random field assessments are sent a letter reminding them of the importance of planting a properly configured refuge.
They are also advised that a followup assessment will occur in the next growing season to determine if an appropriate refuge has been planted. Individuals found to be noncompliant after these two steps will lose access to Bt technologies licensed by Monsanto.
“With refuge compliance figures on the decline it is more important than ever to increase awareness of the importance of insect resistant management to Canadian farmers,” said Chris Anderson, stewardship lead for Monsanto Canada in a release. “This new policy is designed to highlight the significance of planting a mandatory refuge, but to do so in a way that provides farmers the opportunity to take corrective action.”
According to the coalition, CFIA has asked the providers of the seed technology to set up and put in place “corrective action plans to get farm compliance back to acceptable levels.”
“These technologies are approved by the CFIA on condition that (seed companies) ensure that users maintain proper refuge area and configuration on farms,” Schaafsma said.
“Continued non-compliance in terms of the use of refuge could result in the availabilities of these technologies being put at risk. We cannot afford to lose Bt corn technology because of misuse.”
As more Bt traits become available, the coalition warned that refuge requirements may become “trait specific” and vary significantly, so growers must check with the seed provider on the correct refuge to use.
In no instances are there any approved corn technologies with refuge included in the bag, the coalition noted, adding that mixing non-Bt and Bt seed is prohibited.
Current stewardship requirements for Bt corn require a “structured” refuge, in which non-Bt corn is planted in strips, blocks or the perimeter within a Bt cornfield.
A “non-structured” refuge is used when seeding midge-tolerant wheats such as AC Goodeve and AC Unity, which are sold in blends with non-midge-tolerant varieties. But the “refuge-in-a-bag” approach isn’t yet approved for corn.