Arizona cotton growers and pest control advisers are urged to quickly complete the Arizona Department of Agriculture’s (ADA) 1080 application-permit if they might use the insecticide Transform WG (sulfoxaflor) (Dow AgroSciences) under a Section 18 exemption this season to manage the lygus bug.
“You should get the exemption before you need the product. This is something you should do ahead of time,” said Peter Ellsworth, University of Arizona IPM specialist.
The entomologist addressed the federal exemption and Transform’s efficacy during a UA field crop technology workshop held in late June at the Maricopa Agricultural Center at Maricopa.
In May, the U.S. Environmental Protection Agency approved the ADA’s request for a Section 18 special exemption for Transform use for lygus control in cotton. An ADA-approved permit allows growers to apply for, and if approved, use Transform from June 1 through Oct. 31, 2017.
“Transform has given us new opportunities and flexibility in lygus control,” noted Ellsworth. “The product is a fully selective material that’s very effective.”
To illustrate Transform’s efficacy against lygus in cotton, Ellsworth showed a PowerPoint slide with two photos. One photo showed a cotton field treated with Transform where lygus had been present. The plants were an average height with good fruiting positions (and fruit).
The second photo showed an untreated check plot without Transform use. The lygus were not controlled, resulting in tall vegetative plant growth with fewer fruiting positions and less fruit.
“Many times tall cotton is a telltale sign of lygus injury,” Ellsworth explained.
Two modes of action
In the battle against lygus in Arizona, the insecticide Carbine 50 WG (Flonicamid) (FMC) is an existing crop protection tool registered for lygus control in cotton. He says the availability of Transform and Carbine allows growers to rotate these products, using two different modes of action (MoA) to help reduce product resistance down the road.
Ayman Mostafa, University of Arizona area Extension agent, says the ADA permit for Transform can be requested from and returned to ADA. ADA’s contact information includes: an online link to download the permit application and return it by e-mail; or fax at (602) 542-0466, or by mail to: ADA, 1688 W. Adams Street, Phoenix, Ariz. 85007.
If the permit is approved, ADA will assign a permit number required to purchase and report Transform WG usage under the Section 18 label directions.
According to Mostafa, “Transform WG is a critical tool for Arizona cotton growers with the ability to control lygus populations and suppress whitefly populations without harming predators and other natural enemies present in the cotton system.”
He adds, “This is important to the continued success of Arizona’s “selective” cotton IPM program that conserves natural enemies which help maintain pest levels below the threshold.”
Transform is a key chemistry and the only member of the sulfoxamine chemistry class, the Extension agent says, making it “the ideal rotation partner with Carbine.” Mostafa calls Carbine 50 WG (from FMC) an effective lygus control chemistry which, like Transform, is a safe product with natural enemies. EPA approved Arizona counties where Transform can be used in the Grand Canyon State for lygus in cotton include Graham, Greenlee, Gila, Cochise, Pima, Pinal, Maricopa, Mohave, La Paz, and Yuma.
Mostafa says Transform applications can be by ground or air at 1.5-2.25 ounces per acre with a seasonal maximum of 8.5 ounces per acre. The pre-harvest interval is 14 days with the restricted entry interval at 24 hours.
On bee safety, applicators should pay close attention to label restrictions, he says. Growers should work with beekeepers and both should review the Arizona Management Plan for the Protection of Pollinators found online.
On thresholds, Mostafa says Transform works best when used according to established thresholds of not less than 15 total lygus per 100 sweeps with at least 4 nymphs per 100 sweeps (a 15:4 ratio).
Guidelines and other information are available from UA Cooperative Extension.
On pesticide resistance management, Mostafa reminds growers to observe the first principles of resistance management by limiting the user of any MoA to the lowest practical level, diversifying MoAs as much as possible, and partitioning MoAs in space or time to segregate usage as much as practically possible.
In Arizona, a separate approved Section 18 also allows Transform use for sugarcane aphid (SCA) in any sorghum species. There is an SCA application, just like for lygus in cotton, which must be completed and approved by ADA.