EPA has approved a Section 18 emergency exemption for the application of sulfoxaflor or Transform WG in Texas, effective today (April 11) to help control sugarcane aphids in grain sorghum.

Earlier, EPA granted full registration of Bayer's Sivanto to help control sugarcane aphids in grain sorghum. With the emergency exemption for Dow AgroScience’s Transform WG, growers will now have a choice in treatments to use.

Transform WG was used extensively in grain sorghum fields across Texas in the 2015 and 2016 growing seasons to help control outbreaks of sugarcane aphids, especially in the sorghum-rich coastal Texas region. The product was also used in a number of other states where sugarcane aphids reached threshold levels.

But the Section 18 emergency exemption for use of the pesticide expired in October last year after a U.S. District Court in California revoked its registration for use because of concerns about its impact on honeybees.

A federal court rejected EPA's unconditional approval of sulfoxaflor last fall when the U.S. Ninth Circuit Court of Appeals ruled EPA did not have enough data when the agency granted unconditional approval of sulfoxaflor in 2010.

Resistance strategy advanced

The EPA approval provides growers with a second choice chemical to be used this year to combat what is expected to be an outbreak year for sugarcane aphids, especially in Deep South Texas and across the Gulf Coast region.

The aphid has caused problems in grain sorghum from western Mexico into the lower Great Plains, and throughout the South as far north as North Carolina. The court, which historically is sympathetic to legal challenges to pesticides, ruled EPA should not have granted unconditional approval and instead should have granted conditional approval only, allowing limited use of the insecticide.

This latest Section 18 emergency use approval falls within the guidelines of the court's ruling last year.

Sivanto's active ingredient is flupyradifurone of the chemical class Butenolide and is the only member of a new class of insecticides: IRAC Group 4C. Transform WG insecticide features the active ingredient sulfoxaflor.

As with most insecticides, use restrictions apply to both Tranform and Sivanto. For Transform, a pre-harvest interval applies, specifically, do not apply the insecticide within 14 days of grain or straw harvest or within 7 days of grazing, or forage, fodder, or hay harvest. Also, a restricted entry interval (REI) of 24 hours must be observed.

Two applications a year

EPA limits applications to two per acre per year. A minimum treatment interval prevents applications less than 14 days apart, and no more than 3.0 ounces of Transform WG (0.09 lb ai of sulfoxaflor) per acre per year is allowed.

For Sivanto, use restrictions include a 21 day pre-harvest interval. Refer to label use instructions or contact your county agent for other restrictions that apply in your area.

In South Texas, so far, only light pressure from sugarcane aphids has been reported in the Rio Grande Valley and the Coastal Bend. In both areas, over-wintering of the SCA have been reported in Johnsongrass. So far no notable outbreaks of SCA have been reported, but regular and consistent scouting for SCA is recommended in grain sorghum fields.

“Sugarcane aphids multiply quickly so we need to scout early and often. Early applications of an insecticide with a unique mode of action will help keep those populations in check,” says Robert Bowling, AgriLife Extension entomology specialist at Texas A&M. 

In a press release on the granting of the Section 18, Dow AgroSciences said it is working diligently to support re-established EPA Section 3 registrations of products containing sulfoxaflor in all previously labeled crops. Growers are advised to refer to individual state Section 18 labels for complete application guidelines and limitations.

For more information on sugarcane aphids, visit http://bit.ly/1Edwh8N.