Monsanto recently called attention to a violation of Environmental Protection Agency (EPA) rules when Bacillus thuringiensis (Bt) cotton was planted in 10 northern Texas Panhandle counties last year.

Because Bt corn is an alternate host for several cotton pests, says Carl Patrick, Extension entomologist in Amarillo, EPA established insect-resistance management rules requiring certain size refuges for both crops.

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

In the 10 counties, (Dallam, Sherman, Hansford, Ochiltree, Lipscomb, Hartley, Moore, Hutchinson, Roberts and Carson) an exception allows corn producers to plant a ratio of 80% Bt corn and 20% non-Bt corn, because cotton was not grown there at the time Bt technology was accepted, he says. The exception was granted with the stipulation no Bt cotton would be planted in the 10 counties.

Monsanto representatives say 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, says Scott Baucum, a Monsanto representative from St. Louis, MO. Of the 125,000 acres of cotton in the 10 counties last year, about 56,000 acres were planted to a Bt variety.

While no Bt cotton may be planted at this time, the good news, Patrick says, is in the short history of cotton growing in this region, bollworms — the major pest Bt controls — haven't caused major problems. Information on non-Bt varieties that have performed well will be provided to all Extension agriculture agents in the 10 counties, as well as the area gins, he says.