As companies continue to search for new modes of action, existing chemistries are getting a makeover in response to the resistance issue.
In 2010, BASF launched Kixor, and growers applied the family of products containing the active ingredient on more than 10 million acres. “That is a reflection that producers wanted a product that controls glyphosate-resistant broadleaf weeds,” Westberg says. “It has been a tremendous success.”
DuPont expects to introduce Leadoff to the mid-south market after the product receives regulatory approval. Leadoff is for fall burndown application in corn and soybeans to control winter annuals.
Valent’s Valor can be applied in the spring up to seven days before planting corn and up to three days after planting soybeans. It also can be applied in the fall. Valent will introduce an additional preemergence herbicide in 2011 called Fierce, which contains flumioxazin (the active ingredient in Valor) and pyroxasulfone.
Monsanto is partnering with several herbicide suppliers, including Valent, FMC and MANA Crop Protection, to encourage the adoption of a preemergence or postemergence herbicide program. Announced this fall, Roundup Ready Plus will offer producers rebates of up to $6/acre if they use select products in the Residual Rewards program.
Monsanto’s Warrant is a postemergence herbicide that can be applied on soybeans from the first trifoliate to the first reproductive stage. It is for the residual control of small-seeded broadleaf weeds and grasses.
DuPont’s Prequel controls winter annuals and provides contact and residual action in corn. It is designed as a setup treatment for the control of weeds like waterhemp and wooly cupgrass. “We have had a lot of interest in this chemistry in the heart of the Corn Belt,” says Jeff Carpenter, DuPont corn portfolio manager.
The crop protection industry has pushed the resistance message for several years, and experts say it’s starting to resonate. “More and more producers are starting to see problem weeds in their fields and are tackling the problem with other modes of action,” Vail says. “That’s being reflected in increased usage of preemergence herbicides.”
With no new active ingredients expected, a multifaceted approach to combating weed problems is critical. “We can’t simply tank mix our way out of this issue,” Hager says. “Producers need to consider what type of residual program they might need even before they put seed in the ground.”