THE SECOND EDITION OF "A GROWER'S HANDBOOK" IS NOW AVAILABLE

by Tracey Baute, Editor of "A Grower's Handbook," Field Crop Entomologist, OMAf; Ridgetown


Canadian corn producers may recall reading the first edition of "A Grower's Handbook" that was released back in 1999. It contained key information on European corn borer (ECB) biology, how resistance to Bt could develop and the refuge requirements that growers need to follow when using Bt corn. With the ever-changing market of Bt corn technology, including the recent registration of Rootworm Bt corn, the Canadian Corn Pest Coalition realized the importance of revising this book to reflect these changes. Titled "A Grower's Handbook: Controlling Com Insect Pests with Bt Corn Technology," the second edition is now available through seed dealers, seed corn company representatives, Ontario Ministry of Agriculture & Food resource centres, provincial extension personnel and is also available in pdf format on the Canadian Corn Pest Coalition website at: www.cornpest.ca. This free 24-page booklet is full of new information including corn rootworm (CRW) distribution and biology, detailed descriptions of the two species of rootworm present in Canada, what their damage looks like and best management practices to follow for this pest. New maps and life cycle illustrations were created for both ECB and CRW and a table of all currently registered Bt corn products in Canada was also provided. High quality photographs taken by Dr. Marlin Rice of Iowa State University can be found throughout the booklet, which accompany the descriptive text and can be used for identification purposes when scouting corn fields. Most importantly, this book highlights the insect resistance management (IRM) strategies set by the Canadian Corn Pest Coalition, in accordance with the Canadian Food Inspection Agency. Continual use of any insecticide, including Bt corn can lead to the insect pest developing resistance to that product. To prevent or delay this resistance, the Canadian Food Inspection Agency requires that the registrants of Bt corn ensure that IRM plans are being implemented. Producers planning to grow Bt corn, whether it is ECB Bt corn, ECB Bt sweet corn or CRW Bt corn, will need to implement these plans. With two different Bt corn products now available in Canada to control two very different insect pests, figuring out how to implement these IRM plans can get a little confusing. This booklet helps to sort out these issues and is a valuable tool for producers who grow Bt corn in Canada. Insect Resistance Management Requirements: Producers already familiar with the refuge planting requirements used when growing ECB Bt corn, may not be aware that there are a different set of refuge requirements used when growing Rootworm Bt corn. To clarify these differences, a four-page foldout is provided within the book to allow for side by side comparisons of these requirements. In general, a minimum of 20% of a grower's total corn acreage needs to be planted to non-Bt corn, whether planting ECB Bt corn, YieldGard Rootworm Bt corn or the stacked version (YieldGard Plus), which controls both ECB and CRW. The difference is where 20% refuge must be planted.
For ECB Bt corn, the refuge can be planted in a nearby field or within the same field as the Bt corn plantings, as long as it is within 400 metres of the Bt corn plantings.
No matter what Bt corn product is planted, mixing Bt and non-Bt corn seed at planting is not permitted. Both the refuge and Bt corn hybrids should be of similar maturities (100-150 CHU), disease resistance, herbicide tolerance, standability and other traits to ensure similar attractiveness for the insects and to make harvesting easier. Keeping accurate records as to where Bt and non-Bt corn are planted each year is very important. It allows the grower and company representatives to monitor for resistance as well as evaluate hybrid performance.
The refuge planting options have not been changed, with Whole Field, Blocks, 6 rows or wider Strips or Headlands being possible configurations to use for the non-Bt refuge. However, when using YieldGard Rootworm Bt corn, the Whole Field option must be done within a field that is directly adjacent to the Bt corn field. Detailed descriptions on how to configure your non-Bt refuge are provided in the handbook.
The threat of resistance to Bt corn is very real and, therefore, producers need to follow these requirements to maximize the duration of all Bt corn products. The Canadian Corn Pest Coalition (CCPC) is committed to the responsible deployment of Bt corn technology. Comprised of representatives of the seed corn industry, grower associations, regulatory agencies, academic institutions and extension and research staff from both provincial and federal governments, the CCPC has produced the second edition of "A Grower's Handbook" to educate and promote sound stewardship of all Bt corn technology.
This book is only a part of the proactive approach taken by the CCPC. To find out more about the CCPC, Insect Resistance Management, and other news on corn insect pest research, feel free to visit our website at: www.cornpest.ca. A French version of this new booklet will be made available shortly at the same venues as the English version, including the CCPC website.
Since rootworm biology and mating behavior is different than ECB, the refuge for YieldGard Rootworm Bt corn must be planted within or directly adjacent to the YieldGard Rootworm Bt corn plantings. If planning to grow YieldGard Plus Bt corn, which controls both CRW and ECB, the refuge strategy used is the one set for YieldGard Rootworm Bt corn, that is, the non-Bt refuge must be within or directly adjacent to the YieldGard Plus Bt corn planting.