Philadelphia, August 24, 2010 — When growers can’t get into their soybean fields due to cool, wet, La Niña weather patterns during planting time, spring applications of herbicides are sometimes delayed or skipped, allowing weeds to become too large and too dense to control. To ensure fields are clean to start, and stay clean throughout the growing season, agronomic experts recommend early fall residual and burndown applications.
According to Brent Neuberger, Midwest regional technical rep with FMC Corporation, failure to apply a preemergence herbicide in the fall can lead to damaging weed populations and yield losses the following growing season.“If there ever was a spring that showed that, this spring did,” says Neuberger. “By the time fields were dry enough for growers to get into the fields in the spring, these weeds were well established and much more difficult to control. Controlling them in the fall is by far a much easier prospect than trying to get after these larger weeds in the spring.”
Growers can give their soybean crop an early advantage by applying a fall herbicide that provides residual and burndown such as the Authority® herbicide line of products from FMC. Cleaning up the fields and controlling tough winter and summer annuals is important to get fields off to a quick start come planting season. Fall applications of an Authority product provide the long-lasting residual control that is needed to keep fields clean until spring.
“A fall application means growers aren’t relying on doing all of their work in the spring,” Neuberger says. “They are getting those weeds when they are very small and the most susceptible, plus preventing new weeds from germinating.”
FMC offers Authority® First DF, Authority® MTZ and Authority® Assist herbicides for fall applications, as well as Rage® D-Tech herbicide for burndown. Also, FMC plans to release a new addition to the Authority line of products this fall. These herbicides offer residual control for clean fields during planting.
“Residual herbicides can do a couple of different things,” says Dr. Bryan Young, professor of weed science at Southern Illinois University at Carbondale. “One, they can reduce the amount of weeds that can survive and emerge out of the soil and actually get exposed to a potential postemergence application with glyphosate. The other thing they do in terms of time management for applicators, whether that be a grower or commercial applicator, is give a grower a little bit more time to make a timely postemergence application. It will typically delay the development of the weeds that do escape the preemergence residual herbicide so by the time the grower gets to the field, they are smaller in size and fewer in density.”
Utilizing fall or spring preemergence products from FMC Corporation is also beneficial for growers who use glyphosate in their soybean weed management program. And when weed resistance issues are a challenge for growers, a spring preemergence application will help provide a different mode of action, reducing the concern for yield loss.“In any system where glyphosate is not providing the effectiveness of weed control as it has in the past, we’re seeing a lot of value in the use of residual herbicides in the spring,” says Young. “Growers really need to look at soil residual herbicides that…diversify our approach to weed management.”