By Andi Anderson
Waterhemp remains one of the most difficult weeds for crop producers to manage across Ohio and other parts of the Midwest. The weed has become increasingly challenging due to the development of herbicide resistance, making effective control strategies more important than ever. To help address this issue, a new herbicide product, Convintro (diflufenican), will become available for use in corn and soybean production during the 2027 growing season.
Diflufenican introduces a new active ingredient and a new site of action, classified as a Group 12 PDS inhibitor. This addition provides growers with another option to include in their weed management programs. However, experts emphasize that the product should not be used as a stand-alone solution for waterhemp control.
The product is labeled for preplant and preemergence applications in both field corn and soybean production. In corn, application rates range from 2.4 to 4.1 ounces per acre, while soybean rates range from 2.4 to 4.9 ounces per acre. Diflufenican can help manage troublesome weeds, including waterhemp, Palmer amaranth, redroot pigweed, and smooth pigweed.
Researchers and agronomists recommend applying the product as part of a tank mix with other effective herbicides. According to field trials conducted across Ohio and the Midwest, diflufenican alone provides approximately 60% to 70% control of waterhemp. These results demonstrate that while the product has activity against the weed, it performs best when combined with other herbicides that offer additional sites of action.
The product may be applied before planting or shortly before crop emergence. However, it should only be applied once during the growing season. Growers are also advised not to tank mix diflufenican with isoxaflutole or any herbicide product containing isoxaflutole.
As with many preemergence herbicides, environmental conditions can influence both weed control effectiveness and crop response. Under certain circumstances, temporary crop effects such as leaf bleaching and stunted growth may occur. The likelihood of visible injury may increase during cold and wet weather conditions, which can place additional stress on crops.
Other factors that may increase crop injury risk include soil pH levels of 7.5 or higher, organic matter levels below 0.5%, applications made alongside soil-applied organophosphate pesticides, spray overlap areas, and shallow-planted crops. Growers are encouraged to carefully consider these conditions before application.
Agricultural specialists believe diflufenican can become a valuable addition to integrated weed management programs. By adding another site of action, the product may help improve resistance management and support long-term weed control efforts.
The new herbicide option was recently discussed in detail on the War Against Weeds podcast, which featured Dr. Bryan Young, Purdue University Professor of Weed Science, and Dr. Kati Price, Bayer Crop Science Technical Product Lead. The discussion explored product performance, application guidelines, and its role in modern weed management programs.
As herbicide resistance continues to challenge crop production, the introduction of diflufenican provides growers with another tool to help manage difficult weed populations. When incorporated into a comprehensive weed control program, the product has the potential to improve waterhemp management while supporting successful corn and soybean production.
Categories: Ohio, Sustainable Agriculture