Bayer has shipped the first U.S. load of Convintro herbicide, a new Group 12 pre-emergent option featuring diflufenican chemistry that provides a different site of action to help manage herbicide-resistant waterhemp and Palmer amaranth in corn and soybean production.
- Convintro received EPA unconditional registration on June 30 for use in field corn, seed corn, corn silage, and soybeans
- The herbicide uses diflufenican, a new active ingredient to the U.S. that inhibits carotenoid biosynthesis with Group 12 chemistry
- Waterhemp and Palmer amaranth populations are now resistant to up to nine herbicide sites of action
- Uncontrolled waterhemp reduces corn yields an average of 43% over three years, while Palmer amaranth can reduce soybean yields by up to 79%
- Application limits include ground application only, maximum 4.1 fl oz per acre in corn and 4.9 fl oz per acre in soybeans, with one application per year allowed
Bayer has made the first U.S. delivery of Convintro herbicide. It shipped the product from its Kansas City manufacturing facility to New Century FS in Ruthven, Iowa, as the company readies a new pre-emergent option for corn and soybean growers for the 2027 season.
Bayer marked the delivery Friday in a company release. The Environmental Protection Agency (EPA) issued an unconditional registration June 30 for the product, Diflufenican SC500 Herbicide, with Convintro as an alternate brand name. The registration covers field corn, seed corn, corn grown for silage and soybeans, according to the EPA-stamped label.
The selling point is a different site of action. Convintro brings Group 12 chemistry to U.S. corn and soybean production through diflufenican, an active ingredient new to the U.S. that inhibits carotenoid biosynthesis. Bayer is pitching it as an early-season residual and a tank-mix partner for other residual herbicides, with the goal of easing pressure on post-emergence programs.
The targets are waterhemp and Palmer amaranth. Bayer said populations of both are now resistant to up to nine herbicide sites of action, citing the International Survey of Herbicide Resistant Weeds. Bayer cited research showing that uncontrolled waterhemp cut yields an average of 43% over three years. Palmer amaranth can reduce soybean yield potential by up to 79% at 2.5 plants per foot of row. Without competition, a single female plant of either species can produce up to 1 million seeds.
Kenin Eubank, U.S. crop protection business lead for Bayer, framed the delivery as a step in resistance management.
"There's more than herbicide on this truck — there's a new chapter in the fight against resistant weeds," Eubank said.
The label carries several limits. The product may be applied only from the ground; aerial application is prohibited. Use is prohibited in California, Alaska and Hawaii, and in Florida outside 26 listed counties. Growers may make one application per year, at no more than 4.1 fluid ounces per acre in corn and 4.9 fluid ounces per acre in soybeans. They may not tank-mix it with any product containing isoxaflutole. Users must also check Endangered Species Protection Bulletins and meet runoff mitigation requirements.
State registration is still being worked out. Bayer said growers should check with their state department of agriculture, local dealer or representative for the product's registration status, since not all products are registered in all states.
