MANHATTAN, Kan. -- Grain sorghum producers in Kansas may have a new herbicide available for use this summer, but that's not yet a certainty.

"Producers cannot yet assume that the U.S. Environmental Protection Agency will approve an emergency exemption for use of Lumax herbicide on grain sorghum," said Dave Regehr, K-State Research and Extension weed scientist.

"If producers have heard that it's definitely okay to use Lumax on grain sorghum this year, that's incorrect at this point. The EPA is still taking comments from the public on this exemption, and it cannot make any decisions until the comment period has ended. It's premature for producers to make any assumptions about what will happen," Regehr said. "Until we hear differently, producers cannot legally use Lumax on grain sorghum."

Lumax is a premix containing the active ingredients in Callisto and Dual Magnum, along with a low rate of atrazine. It is manufactured by Syngenta Crop Protection, and is currently labeled for use on corn.

If the emergency exemption for use on grain sorghum is approved, producers could obtain improved control of triazine- and ALS-resistant Palmer amaranth and waterhemp, and better preemerge control of large-seeded broadleaf weeds, especially velvetleaf, kochia, sunflower, and morningglory, the agronomist said.

If Lumax is approved for use on grain sorghum, producers must use Concep-treated seed. Concep is a treatment that makes seed safe against herbicides that contain alachlor, dimethenamid-P or s-metolachlor.

SOURCE: K-State Research and Extension news release.