IRM Reminder
U.S. Environmental Protection Agency (EPA) regulations require each grower who plants Bt corn hybrids to sign and return an IRM Stewardship Agreement.

If we do not have a signed IRM Stewardship Agreement from you on file for Hoegemeyer corn hybrids, you will receive one under separate cover to sign and return via postage-paid mail.

Refuge Management
A corn borer refuge is corn that doesn't control corn borers. If you grow corn borer protected Bt corn, you must plant an effective non-corn borer Bt refuge of 20% within 1/2 mile of the Bt corn fields you plant. An effective refuge must provide a sufficient quantity of susceptible corn borer moths that are available to mate with moths that could be resistant to Bt corn.

Refuge Size
The EPA and Hoegemeyer Hybrids require that growers plant no less than 20% of their corn acres to non-Bt hybrids, which do not control corn borer. (Cotton growing counties require that 50% of the corn acres must be planted to non-Bt hybrids.)

Refuge Distance from a Bt Field
The EPA and Hoegemeyer Hybrids require that the non-Bt corn refuge, which does not control corn borer, be within 1/2 mile (preferably 1/4 mile) of the Bt field. To achieve optimum results, planting the refuge within the same field, or as close as possible, is recommended. A neighbor's field does not qualify.

Bt Corn Refuge Hybrid Choice
An effective refuge is best achieved by choosing a non-Bt hybrid that does not control corn borer, that is agronomically and managed similar to the Bt hybrid being used.

Refuge Layouts
Each grower planting Bt corn must plant their own refuge. A neighbor's field does not qualify as a refuge. The EPA accepts the following refuge planting practices:

Acceptable Planting Patterns for a 20% Non-Bt Corn Refuge in a Bt Corn Field:

1. Planting a large non-Bt corn borer block within the Bt field.
2. Splitting the planter to alternate at least four rows (preferably 6 rows) of non-Bt corn, which does not control corn borer, in a Bt corn field. Each strip of non-Bt corn must be at least 4 rows wide.
3. Planting field perimeters or end rows to non-Bt corn, which does not control corn borer, in a Bt corn field. (If only end rows and perimeter rows are used as refuge acres, they must comprise 20% of the corn acres to be acceptable as a refuge.)
4. Pivot corners cannot be used as non-Bt refuge acres. Non-Bt refuge acres must be a block within the pivot circle.
5. Plant non-Bt in a separate field that is within 1/2 mile (preferably 1/4 mile) of the Bt field.

(NOTE) Late planted and/or early harvested sweet corn does not qualify as a refuge, since it would not serve as an effective host for all corn borer generations during a growing season.

(NOTE) Only if the economic thresholds are reached can the refuge area and Bt area be treated with the proper insecticides for target pests. Bt-based microbial insecticide products (Dipel is an example) must not be used on the refuge area.