Irrigated acreage, high yield goals likely to benefit from BG II

West Texas cotton farmers interested in irrigating or trying to top 600 pound per acre yield goals likely will be the early adopters of Bollgard II. With those targets, farmers should be comfortable investing in the new technology, says Walt Mullins, U.S. cotton technical manager for Monsanto.

Mullins, during a Southwest Farm Press interview at the recent Beltwide Cotton Conferences in San Antonio, said Bollgard II offers “another risk management tool” to cotton farmers. He said the new double-gene cotton varieties also will be less vulnerable to insect resistance.

“Bollgard II contains a new gene with a different mode of action in relation to the original gene in Bollgard,” Mullins said. “It has more activity against armyworms and loopers and expresses control at a very high level, more than Bollgard I.”

He said pests such as beet armyworms, fall armyworms and bollworms that were not vulnerable to Bollgard I are susceptible to Bollgard II.

“West Texas farmers don't have beets every year,” he said, “but when they get them growers can spend $30 to $40 to control them and still lose yield. With a reasonable pricing structure for West Texas, Bollgard II makes sense, especially for irrigated acreage.”

He said the new technology also controls bollworm and fall armyworm effectively. “We might see rare cases where we need to spray once, but with Bollgard I, under similar pressure, we would have had to spray two to three times and with conventional cotton possibly even more than that.”

He said bollworms have become a more troubling pest for West Texas cotton farmers than the budworm, which is vulnerable to Bollgard I.

Pink bollworms are vulnerable to either BG I or BG II.

“Historically, pink bollworms have not been a big issue for most of West Texas,” Mullins said, “but they are moving north. With either of the Bollgard products, pinkies will not be a threat.”

He said some of the early generations of Bollgard II/Roundup Ready varieties did not measure up to the yield potential of some of the elite Bollgard lines, but this should disappear with subsequent generations that include Roundup Ready Flex.

“We understand that value is extremely important to the grower and that they have to have varieties with yield potential. The university official variety trials conducted in 2005 demonstrate that yields have improved with Bollgard II/Roundup Ready Flex varieties.”

Mullins said the double gene structure also improves product stewardship. “With the single gene, we had concerns with resistance. Monsanto is committed to the two-gene product and at some point in time would like to see it replace the single gene product. But we want to make sure that growers have the appropriate range of agronomic characteristics in varieties they need in these Bollgard II lines so that this conversion is as natural as possible.”

He said the two genes have different modes of action, making resistance a more remote possibility. “We believe the frequency of resistance to both genes in target pests is very small,” he said. “Combined with an appropriate refuge plan, we believe we'll have a sound resistance management program.”

He said the new Roundup Ready technology, Roundup Flex, will complement Bollgard II to improve overall efficiency. “Seed companies have decided that they will not include the Flex gene in Bollgard I varieties,” he said.

Mullins said BG II technology could improve overall yield even when insect pressure is low. “A 30 to40 pound increase in yield is all it takes to pay for the Bollgard II technology.”

He said experience in Tennessee showed that low levels of bollworm infestations caused production losses in non-Bt cotton, even though populations never built to treatment thresholds. Even under the lower insect infestation environments in Tennessee, Bollgard varieties averaged a 6percent to7 percent increase in yield over non-Bt variety yields. “Early on we didn't think that we had a market for Bollgard in Tennessee, but today the state is 95 percent Bt varieties”

He anticipates similar results in West Texas with Bollgard II, “with good agronomic varieties.”

He said in most cases BG II should eliminate pyrethroid use for bollworms. Avoiding pyrethroid use in West Texas cotton, particularly earlier in the season, will also significantly reduce aphid and/or spider mite flare problems later in the season.

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