Insect Resistance Management of Bt Corn in Canada

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The Plant Biosafety Office (PBO), formerly the Plant Biotechnology Office, of the Canadian Food Inspection Agency (CFIA), is responsible for the regulation of plants with novel traits (PNTs) in Canada under the Seeds Regulations Part V and as described in two regulatory directives: Dir94-08 Assessment Criteria for Determining Environmental Safety of Plants with Novel Traits and Directive 2000-07 (Dir2000-07): Conducting Confined Research Field Trials of Plants with Novel Traits in Canada. Prior to commercialization of a PNT, a proponent must apply to the PBO for an environmental safety assessment in accordance with Dir94-08. The PNT may be authorized for environmental release with or without conditions as determined on a case-by-case basis.

The advent of plants which express Bt toxins also present in commercially available foliar Bt products has led to concern over the eventual development of resistance to this insecticide. Consequently, the five companies which have received authorization for Bt-corn in Canada (Monsanto, Pioneer, Novartis, DeKalb and Mycogen) have each developed resistance management plans (RMPs) designed to delay development of Bt resistant insects. Authorization of Bt plants in Canada requires the implementation of these RMPs and is written into letters of authorization as an Addendum.

The companies which market Bt corn in Canada have different resistance management plans and an effort has been underway for the past year to come up with a single plan which will be used as an industry standard to avoid the confusion that may arise if a grower purchases Bt corn seed from two different companies with two different RMPs. This work has been undertaken by the Bt Corn Coalition, a group representing the private and public sector consisting of growers, provincial extension personnel, publically funded researchers from Agricultre and Agri-Food Canada and the University of Guelph, and seed industry representatives. The Bt Corn Coaltion was successful in developing such a plan.

In October, 1998, the PBO was presented with the report Responsible Deployment of Bt Corn Technology in Ontario by the Bt Corn Coalition for adoption by Bt corn stakeholders in Canada. The report endorses, and is consistent with, the recommendations of United States Department of Agriculture North Central Regional Research Committee as published in North Central Regional Publication 602 Bt Corn & European Corn Borer: Long-Term Success through Resistance Management and it's October 1998 Supplement. The PBO has reviewed the Report and finds it to represent the most current and credible scientific information on insect resistance management of Bt corn. In particular, the mandatory implementation of a minimum 20% unsprayed refuge of non-Bt corn on each farm planted with Bt corn is considered a critical component for the responsible management of this technology. The Resistance Management Plan (see Appendix I) presented in the Report will be reviewed on an ongoing basis by the Bt Corn Coalition and amended as required by them in consultation with the PBO, in order to reflect any new scientific information which may impact on the efficacy of the plan.

Given the provision of new information to the PBO by the Bt Corn Coalition as set out in the Report, the PBO has amended the conditions of all authorizations for the unconfined release of European corn borer resistant corn under the authority of Section 112(2)(b)(ii), Part V of the Seeds Regulations. From December 3, 1998 forward, the authorizations of Bt corn in Canada are conditional on the implementation of the Resistance Management Plan submitted by the Bt Corn Coalition as set out in the Report and presented here in Appendix I. All companies which have received authorization for the unconfined release of Bt corn, and their licensees, must ensure that all conditions of sale of Bt corn seed and any related advertising or informational literature is changed to incorporate the RMP before 1 January 1999.

For more information, please contact:
National Manager
Plant Biosafety Office
Plant Health and Production Division
Canadian Food Inspection Agency
59 Camelot Drive
Nepean, Ontario, Canada K1A 0Y9
Phone: (613) 225-2342
Fax: (613) 228-6629

For information about the Bt Corn Coalition, please contact:
Dr. Mark K. Sears
Professor and Chair
Department of Environmental Biology
University of Guelph
Guelph, Ontario, Canada N1G 2W1
Tel: (519) 824-4120
Fax: (519) 837-0442

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Appendix I

Position Statement of the Bt Corn Coalition

The Bt Corn Coalition endorses the recommendations submitted by NC-205.

We recognize and accept that all individuals and institutions in Canada involved in Bt technology are responsible for its proper use and stewardship.

The seed industry accepts responsibility for maintaining and marketing Bt corn hybrids that deliver a high dose of Bt toxin throughout the season, and for continuing to produce high quality non-Bt corn hybrids that can serve as refuge areas for Bt-susceptible European corn borers.

Corn producers accept responsibility to apply appropriate measures for management of resistance by corn borer populations to Bt toxins to ensure extended use of this technology.

The research and extension community accept responsibility to provide scientifically based information pertinent to the use of this technology and to transmit this information in a timely and clear manner to the seed industry and to corn producers.

Our recommendations for implementing a resistance management strategy include:

All growers should plant a minimum of 20% non-Bt corn not sprayed with insecticides on their planted acreage each year.

Non-Bt corn should be planted within 1/4 mile of the farthest Bt corn in a field to provide a refuge where Bt-susceptible moths may exist.

Non-Bt corn hybrids for use as refuges in a field should be selected for growth, maturity and yield traits similar to the Bt hybrid used in the remainder of the field.

Refuge areas may be planted in blocks on the edges or headlands of fields or in strips across the entire field. When refuge corn is planted in strips across a field a minimum of 6 rows should be planted with non-Bt corn alternating with Bt hybrid across the entire field. Refuge created by mixing seed in the hopper is ineffective.

The Bt Corn Coalition recommends that individual corn producers using Bt technology be responsible to ensure that the minimum 20% refuge occurs on their farm.

The Bt Corn Coalition unanimously agrees that a single, clear and concise message concerning stewardship of Bt technology is essential for all groups and individuals concerned and for public awareness and acceptance.