Growers Welcome Natural Refuge for Bollgard II

The option of not planting an Insect Resistance Management (IRM) refuge of non-Bt cotton when growing Bollgard II cotton - and relying instead on a "natural refuge" - is getting a big thumbs-up from growers, consultants and academics alike.

The natural refuge option, available in certain areas, allows producers to plant varieties containing the Bollgard II trait and to rely on other naturally occurring crops and plants surrounding the Bollgard II cotton fields to serve as a refuge. That means none of the 95-5, 80-20, embedded, sprayed or unsprayed decisions and implementation will have to be managed by the grower. Growers in these areas also will not have to grapple with proper refuge distances and all the other challenges involved in planning, planting and managing cotton refuge acres.

"Working closely with the United States Department of Agriculture and university researchers, Monsanto has been able to demonstrate that sufficient numbers of tobacco budworm and bollworm moths develop naturally from hosts other than cotton," says Walt Mullins, Monsanto cotton traits technical manager. "The natural plant landscape, along with other crops besides cotton, will provide adequate refuge for Bollgard II fields."

Growers may utilize the natural refuge option for varieties containing the Bollgard II trait in the following states: Alabama, Arkansas, Florida, Georgia, Kansas, Kentucky, Louisiana, Maryland, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Virginia and most of east and west Texas (excluding the Texas counties of Brewster, Crane, Crockett, Culberson, El Paso, Hudspeth, Jeff Davis, Loving, Pecos, Presidio, Reeves, Terrell, Val Verde, Ward and Winkler).

It also remains the case that Bt cotton cannot be planted in the Texas Panhandle counties of Carson, Dallam, Hansford, Hartley, Hutchinson, Lipscomb, Moore, Ochiltree, Roberts and Sherman, as well as south of Highway 60 in Florida. These general restrictions have not changed with the approval of the natural refuge for Bollgard II cotton.

The natural refuge does not apply to Bollgard II cotton grown in areas where pink bollworm is a pest, including California, Arizona, New Mexico and the Texas counties outlined above. The reason: The pink bollworm has no natural host besides cotton.

"Our growers are tickled to death that they will be able to rely on the natural refuge with Bollgard II cotton," says Chuck Farr, a leading cotton consultant in northeast Arkansas. "In the Mid-South, with our multiple crop mix, we should be able to provide a good natural refuge for the bollworm and budworm."

Farr points out that roughly 95% of the cotton he services is already planted to Bollgard II. The 5% that isn't Bollgard II are refuge acres. "Historically, our growers have taken a yield and an economic hit on their refuge acres," the consultant explains. "We've had some years where we lost maybe 400-500 pounds of lint per acre to insects on our refuge acres. The average annual loss would probably be around 100 pounds of lint per acre, but this is a significant amount of lost revenue."

Farr also notes that growers realized quickly when they did have to spray refuge acres that the amount needed for insecticide treatments was more than the cost of the Bollgard or Bollgard II technology. "It made our growers realize how much money they are saving by not having to spray insecticides for worms thanks to the Bt technology," he adds.

Dr. J. R. Bradley, research entomologist at North Carolina State University, thinks that cotton growers in the Southeast will welcome the natural refuge option for Bollgard II cotton. "With Bollgard II cotton, there's much less worry about caterpillar pests, and not having to plant an IRM refuge alone is going to reduce yield losses to the cotton grower," Bradley explains. "And another plus for Bollgard II - if you have to manage beet or fall armyworms regularly, it takes additional insecticide dollars, because the original Bollgard does not control these worm species."

Bradley urges cotton growers to move quickly to familiarize themselves with the Bollgard II technology if they haven't done so already. "The risks of extra costs and yield losses associated with the original Bollgard are still pretty high, depending on where you farm," the entomologist says.

Patrick Johnson, a cotton producer in Tunica, MS, says he will not miss the hassle associated with planting an IRM refuge. As a seed producer, he will especially benefit from not having to manage multiple IRM refuges for thousands of acres of cotton. " Because of the purity and segregation issues associated with growing cotton seed, in the past we would harvest 500 acres of one variety, then we would have to gear up for another variety by cleaning up our pickers, buggies and module builders," Johnson says. "We also usually found that planting a refuge meant buying a cotton variety that we would not have planted otherwise."

And then there's the lost yield associated with an IRM refuge: "It could be pretty frustrating watching the cotton insects move into the refuge acres and not be able to spray them," Johnson says.

The natural refuge option does not apply to cotton varieties that contain the single trait version, sold under the Bollgard trademark. Producers who grow the varieties that contain the Bollgard trait are still required to plant a 5% embedded, 5% unsprayed or a 20% sprayed non-Bt refuge associated with the amount of Bollgard cotton they are growing.