By Kelley Tilmon
State Specialist for Field Crop Entomology
Most corn hybrids planted in the U.S. contain one or more transgenic traits for weed or insect management. There are many different available traits, which can sometimes cause confusion about a hybrid’s spectrum of control or refuge requirements. The Handy Bt Trait Table provides a helpful list of trait names and details of trait packages to make it easier to select and understand products and their refuge requirements, and read company seed guides, sales materials, and bag tags. This year’s table was authored by Dr. Chris DiFonzo at Michigan State University with contributions by Drs. Kelley Tilmon (OSU) and Pat Porter (Texas A&M).
A new column has been added to the table in 2017 to address local or regional performance issues in cases where there are documented field-level insect populations which are less susceptible to or resistant to a given Bt protein. An insect is listed in this column only if ALL of the Bt proteins which should control it in a product are ‘ineffective’ somewhere in the US or Canada. Ineffective ratings are based on published lab assays and/or field research from field corn, sweet corn, and cotton. University extension specialists or local educators can assist in determining if you are in an area where reduced effectiveness was reported. On a broader scale, this column is intended to alert growers and consultants to potential management problems, influence seed selection, and encourage field scouting.
The Handy Bt Trait Table can be downloaded
here, along with a list of citations documenting performance issues
here.