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Eradication of the pinkie continues to near, cotton experts conclude, but is not a done deal.
Potency of Bt cotton
Staten and Antilla concur the single most potent weapon has been Bt cotton.
“Bt cotton was a lifesaver,” Antilla said. “If we didn’t have high levels of Bt planting today we would not be this close to eradication. Without Bt cotton in Arizona, residual populations would have existed forever.”
Antilla, working with the ADA and others, successfully lobbied the Environmental Protection Agency to grant a 24c special use registration to allow 100 percent Bt plantings in all Arizona eradication zones without a refuge area.
This allowed Bt cotton to be seeded to 97 percent of Arizona’s acreage. The percentage was 80 percent to 85 percent before the exemption.
Looking ahead, Staten said, “I think by the end of 2010 we’ll have most of New Mexico, West Texas, Arizona, and Mexico’s state of Chihuahua largely un-impacted by the pink bollworm. We are down to finishing and conquering the pink bollworm in the Mexicali, San Luis and Yuma valleys.”
The sterile moth component is another pivotal piece of the eradication puzzle. The USDA managed and California Department of Food and Agriculture-owned sterile moth rearing facility in Phoenix has raised in excess of 20 billion sterile PBW moths since the program’s expansion into Texas and New Mexico.
The moths are sterilized by an onsite irradiator and fed a red dye diet to distinguish sterile and native moths in field traps. Small airplanes drop the moths 500 feet above cotton fields where the native moths try to mate with the steriles.
From 2006-2009, about 19 billion steriles were dropped on cotton fields across the four-state area plus Mexico. The breakdown: California’s SJV – 970 million steriles; Arizona – 7.6 billion; New Mexico – 1 billion; Texas – 5.5 billion; and Mexico – 2.3 billion.
Sterile moth releases have effectively reduced native numbers. However the rearing facility’s limited moth production capabilities have slowed the eradication process.
A scary glitch occurred at the rearing facility last August. Staten says about 350,000 moths missed the irradiation (sterilization) process. The still-fertile moths were mixed with 2.1 million steriles in a transit container loaded into an airplane’s drop machine. The fertile-sterile moth mix was dropped by a single airplane over the Fabens, Texas area located east of El Paso.
“We are uncertain how this happened,” Staten explained. “We quickly responded with a pheromone rope treatment and future sterile releases in the area. There is no evidence of pinkie reproduction in the Fabens area this year.”
In another setback, tragedy marred the sterile release program in May when an airplane dispersing sterile pinkies crashed in a cotton field in Somerton, Ariz., (Yuma County). Pilot Travis Perkins died. Perkins had logged 4,000 hours in the sterile moth release program. Antilla says the National Transportation Safety Board has not released the cause of the crash.
Antilla says PBW eradication will open new doors for farmers to experiment with non-Bt cotton varieties to increase yields. He hopes eradication will lower the current $32/acre technology fee that farmers pay for Bt cotton.