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Posted 31 October 2017. PMN Crop News.

Reactivation Keeps Corn Herbicide Working When Others Stop

Source: Bayer CropScience Press Release.

Research Triangle Park, North Carolina (September 12, 2017)--Growers want to trust their residual herbicide is working as expected, but when dry weather sets in, most herbicides lose residual weed control. For growers, that means increased management costs from unanticipated sprays to stop weed growth. Using a pre-emergence herbicide with reactivation properties helps growers maintain lasting residual weed control, even if weather conditions turn dry.


Typical residual control stops working when the weather conditions become dry, and the herbicide doesn't start working again. Corvus herbicide offers reactivation and with as little as a half-inch of rain it actually does just that it reactivates.

"Reactivation can easily be confused with residual control, but there is a scientific difference between the two," says Mark Waddington, selective corn herbicide product development manager at Bayer. "With a half-inch of rain, the active ingredient actually turns into a different compound and reactivates itself. Then, the herbicide will go back and control weeds that may have emerged while preventing new weed growth."

Grower Lowell Seagren of Ridott, Ill. understands the benefit of reactivation. "It's important to have reactivation because so many herbicides have a short lifetime. If you have a problem, it's mandatory to re-spray which is another added cost," he says.

Continual weed control through reactivation is important to Star City, Ind. grower Austin Mattern. "Phenomenal," he says. "On sandy soils, we have a hard time with solid weed control because sands tend to not hold the herbicide. With Corvus you get that reactivation feature with the rainfall and moisture. So, as soon as it's reactivated you can count on the weeds that started growing with that rain are going to start dying as well with reactivation."

"The power of reactivation is what makes Corvus so unique," says Joshua VanDeWalle, northern region campaign manager for Bayer. "Beyond reactivation, Corvus also features consistent burndown and residual control. It provides broad-spectrum control of grasses and broadleaf weeds, including those resistant to glyphosate-, ALS-, PPO- and triazine-based herbicides."

With almost 10 years of proven performance, Corvus is the No. 1 pre-emergence herbicide brand of choice in the country. Or, as Jerry Elder from Morganfield, Ky. says, "Corvus has been great. The best chemical I've ever worked with since I've been farming."

To learn more about Corvus and reactivation, visit

Bayer is committed to bringing new technology and solutions for agriculture and non-agricultural uses. For questions concerning the availability and use of products, contact a local Bayer representative, or visit Crop Science, a division of Bayer, online at