Non-Bt cotton varieties offer promise for banned area

Some existing cotton varieties offer northern Panhandle growers production equal to the restricted insect-resistance enhanced varieties, said a Texas Cooperative Extension specialist.

Producers are concerned because of a recent notice by Monsanto. The company called attention to the violation of Environmental Protection Agency rules when Bacillus thuringiensis (Bt) cotton was planted in 10 northern Texas Panhandle counties last year.

While no Bt cotton may be planted at this time and a working group has been set up try to get producers access to this technology, there are still many good choices for producers this year, said Dr. Carl Patrick, Extension entomologist in Amarillo.

Patrick said the situation developed because 10 years ago when the Bt technology was accepted, the 10 counties - Dallam, Sherman, Hansford, Ochiltree, Lipscomb, Hartley, Moore, Hutchinson, Roberts and Carson - were a predominantly corn-growing region.

Because Bt corn is an alternate host for several cotton pests, he said, EPA established insect-resistance management rules requiring certain size refuges for both crops. This management technique would prevent insects from becoming overexposed - and resistant - to the new technology.

In Texas, which is primarily a cotton-producing state, a corn producer is allowed to only plant 50 percent Bt corn, with the remainder of the acres planted in non-Bt corn to serve as a refuge, Patrick said.

In the 10 counties, an exception to the 50/50 ratio allows corn producers to plant a ratio of 80 percent Bt corn and 20 percent non-Bt corn, because cotton was not grown there at the time, he said. The exception was granted with the stipulation no Bt cotton would be planted in the 10 counties.

Since then cotton has moved north, and the situation has changed, Patrick said.

“We can't shift that 50/50 thinking back up into the Panhandle, because corn producers want to keep the 80/20 ratio, and many of them are also cotton producers,” he said. “If they cut back to 50/50, there would be a lot more insecticides and miticides sprayed.”

A group has been formed to approach EPA for a change, but first a number of things must be considered, Patrick said. Information on refuge requirements needs to be updated, including how other natural refuges, such as sorghum and other crops, play a role.

However, until EPA can modify the rules, no Bt cotton can be planted, he said.

Monsanto representatives said when they looked at seed sales in 2006, they became aware that growers had planted Bt cotton in the restricted counties.

On the no-plant list are Bollgard, Bollgard II and WideStrike, said Scott Baucum, a Monsanto representative from St. Louis, Mo., who met with both cotton and corn producers. Of the 125,000 acres of cotton in the 10 counties last year, about 56,000 acres were planted to a Bt variety.

However, Patrick said, those acres were planted to those varieties not necessarily for the Bt technology, but for other technology stacked with it.

“We've got this working group pulled together to get things changed in the future, but this year you can't plant Bt cotton,” he said.

The good news, Patrick said, is in the short history of cotton growing in this region, bollworms - the major pest Bt controls - have not caused major problems.

“Bt is outstanding technology, and we'd certainly like for producers to have access to it,” he said. “But we do have non-Bt varieties that have performed well both in commercial fields and in the research-replicated tests.”

Information on these varieties will be provided to all Extension agriculture agents in the 10 counties, as well as the area gins, Patrick said.

In addition, the local Extension Agri-Partner and integrated pest management programs will increase the trapping level for bollworms in those counties, he said.

“We can keep a tab on what the bollworm moth is doing,” Patrick said. “When we see major flights taking place, we can alert the producers to intensify field scouting for bollworm development.”

Producers need to manage their cotton for earliness, he said. The more mature cotton is, the less potential for bollworm damage.

An important aspect is the management of early season pests like thrips, cotton fleahoppers and Lygus bugs through routine scouting, use of economic thresholds and proper insecticide selection, Patrick said.

If an insecticide is required to control early season pests, producers should avoid using a pyrethroid-type insecticide, using an organophosphate type instead, he said

“If you do get into a bollworm problem, we do have economic thresholds to determine when to treat and effective insecticides to use when needed,” Patrick said.

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