There's an alphabet soup of traits and tolerances within field corn these days. The standard for sorting through it all is The Handy Bt Trait Table.
This two-page document lists the types of Bt present in all commercialized corn in the U.S. in a concise format. It presents the trade names for traits, Bt event, protein(s) expressed, targeted insects and herbicide traits.
Going back to the first table in 2009, the Trait Table for field corn has become the standard as an authoritative reference to Bt toxins in corn. Chris DiFonzo, a Michigan State University entomologist, is the primary author, and the latest update of the chart was released Feb. 2, 2023. Find it here: https://www.texasinsects.org/….
DiFonzo noted that companies continue to recombine existing insect modes of action. Syngenta also renamed some trait stacks for 2023, and the updated table offers up both the new and the old nomenclature for reference. Companies also have continued to add Enlist technology (providing tolerance to 2,4-D and fops herbicides) to existing hybrid packages.
"This table is a 'living document,'" DiFonzo told DTN. "There are sometimes updates and corrections, especially in the few weeks after a new version comes out." In other words, keep checking the website for the most recent information.
The publication highlights insect and Bt combinations with documented field failures, confirmed resistance or cross-resistance. The statements are based on published lab assays and/or field research to alert farmers and consultants to potential management problems, help with seed selection and encourage field scouting. Citations for those resistance ratings can be found here: https://agrilife.org/….
It's also important to remember the table is a national publication, and resistance may be widespread, regional, or limited to a few fields. Local seed representatives and Extension personnel can help sort out what resistance pressures are present in your area.
A version for U.S. sweet corn can be found at: https://agrilife.org/….
Pamela Smith can be reached at firstname.lastname@example.org
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