Bt Plant-Incorporated Protectants October 15, 2001 Biopesticides Registration Action Document
more of these target pests. Economic thresholds will be determined using methods recommended by local or regional professionals (e.g., Extension Service agents, crop consultants). Instructions to growers will specify that microbial Bt insecticides must not be applied to non-Bt corn refuges.
b) Cotton-Growing Area Refuge Requirements for Bt Corn
For Cry 1Ab and Cry1F Bt field corn grown in cotton-growing areas, grower agreements (also known as stewardship agreements) will specify that growers must adhere to the refuge requirements as described in the grower guide/product use guide and/or in supplements to the grower guide/product use guide.
Specifically, growers in these areas must plant a structured refuge of at least 50% non-Bt corn that may be treated with insecticides as needed to control lepidopteran stalk-boring and other pests.
Refuge planting options include: separate fields, blocks within fields (e.g., along the edges or headlands), and strips across the field.
External refuges must be planted within ½ mile (1/4 mile or closer preferred).
When planting the refuge in strips across the field, refuges must be at least 4 rows wide, preferably 6 rows wide.
Insecticide treatments for control of ECB, CEW and Southwestern corn borer (SWCB) [Cry1Ab or Cry1F corn hybrids] and/or fall armyworm (FAW) and black cutworm (BCW) [Cry1F corn hybrids only] may be applied only if economic thresholds are reached for one or more of these target pests. Economic thresholds will be determined using methods recommended by local or regional professionals (e.g., Extension Service agents, crop consultants). Instructions to growers will specify that microbial Bt insecticides must not be applied to non-Bt corn refuges.
Cotton-growing areas1 include the following states: Alabama, Arkansas, Georgia, Florida, Louisiana, North Carolina, Mississippi, South Carolina, Oklahoma (only the counties of Beckham, Caddo, Comanche, Custer, Greer, Harmon, Jackson, Kay, Kiowa, Tillman, Washita), Tennessee (only the counties of Carroll, Chester, Crockett, Dyer, Fayette, Franklin, Gibson, Hardeman, Hardin, Haywood, Lake, Lauderdale, Lincoln, Madison, Obion, Rutherford, Shelby, and Tipton), Texas (except the counties of Carson, Dallam, Hansford, Hartley, Hutchinson, Lipscomb, Moore, Ochiltree, Roberts, and Sherman), Virginia (only the
1Counties selected based on approximately 1000 A Bt cotton/5000 A total cotton using 1999-2001 cotton acreage reports from Monsanto and USDA/NASS.