New Herbicides Ready

The newest batch of herbicides are out in the marketplace, and as always, your grower-customers rely on you to help them determine what products are best for their situation.

This means you need to have a pretty good understanding of these products yourself, but finding the time to talk with each manufacturer representative isn’t easy. That’s why Reid W. Acker, our fictional but competent in-house herbicide advisor, is back. He cornered several well-respected weed experts — Bill Johnson from Purdue University, Chris Boerboom at the University of Wisconsin, Ohio State University’s Mark Loux, Aaron Hager of the University of Illinois at Champaign-Urbana, and Iowa State University’s Bob Hartzler — to help sort through your key questions and concerns.

Dear Reid: Is there anything new this year that I should be excited about?

There are two new active ingredients, according to my Extension comrades. One is the fluthiacet-methyl in FMC’s Cadet, which actually came out in April and I talked about briefly in my mid-year 2008 review (see “Just Getting Better”). The other is thiencarbazone, which can be found in Bayer CropScience’s Corvus, a preemergence premix that also contains Balance plus a safener to provide two modes of action to fight glyphosate- and triazine-resistant weeds. Bob Hartzler notes that while both are from established families of herbicides, Corvus contains a new ALS (acetolactate synthase) inhibitor and Cadet is a new PPO (polyphenol oxidase) inhibitor.

But to be honest, it’s a new seed technology that these weed specialists are talking about: LibertyLink soybeans will be launched this year. Mark Loux notes that we already have a lot of good corn herbicides, but LibertyLink soybeans offer a new option for soybean growers, especially for those who have started to have real problems with glyphosate and Roundup Ready soybeans.

As Bill Johnson says, this technology is going to give your growers another tool for managing glyphosate-resistant weeds.

Dear Reid: Since you’ve brought up the topic, how do the new herbicides fit into a glyphosate resistance management program?

Every expert stresses that your growers need to use the herbicides, especially glyphosate, in a multi-faceted approach to avoid resistance.

For example, FMC’s Cadet tackles glyphosate-resistant biotypes, and Valent’s Valor is part of the preemergence herbicide trend, which can reduce the need for glyphosate later.

Aaron Hager says the heyday of using Roundup alone is over in many areas and many fields, especially soybean fields. He cites three reasons: glyphosate-resistant volunteer corn; glyphosate by itself simply not being as strong on some annual broadleaf species, such as morningglories, if application is not properly timed; and glyphosate-resistant weeds.

Chris Boerboom points to FMC’s Authority Assist as one of those preemergence herbicide options as a way to add another mode of action to soybean herbicide programs. By reducing the number of weeds subsequently sprayed with glyphosate, your growers and staff applicators reduce the risk of early season yield loss — and increase the flexibility in spray timing, a critical factor as many growers’ farms get larger.

Hartzler says most growers are looking for something to provide greater flexibility and increased consistency with their Roundup Ready program, and existing products do this very well. However, he adds, in areas of the country where a glyphosate-resistant weed has become a major problem (primarily the Southeast with Palmer’s amaranth), there is a bigger need for new chemicals.

Dear Reid: My growers are concerned about input costs. Any advice?

Boerboom says he promotes preemergence herbicides in both corn and soybeans. That’s because he feels a preemergence herbicide could replace one of the two postemergence glyphosate applications that are needed in many fields — and he says they would cost about the same price.

Certainly we all remember Monsanto’s announcement earlier this year that the cost of Roundup was increasing. Johnson says that could increase the use of other herbicides, just because the issue of disparity in cost is reduced.

Loux says he doesn’t really see any differences in performance between glyphosate products, so he tells growers to use whatever they want.

Can you give us some other pointers on some of the other new herbicides?

Sure. Hager points out that Ignite from Bayer CropScience is actually an old cotton formulation of glufosinate-ammonium that’s getting new life as a replacement for the company’s Liberty herbicide in corn and soybeans.

I read that Rotam North America’s new Primero for corn contains nicosulfuron; you’re probably familiar with that active ingredient from Accent. It can be used in all types of corn and is especially effective in controlling escaped grasses.

Loux says Balance Flexx (isoxaflutole + safener) is a “step forward” for Bayer because it contains a safener that prevents Balance from injuring corn. That allows it to be applied early postemergence to provide residual when mixed with other herbicides that control emerged weeds. At presstime, it was still awaiting EPA approval, but Bayer expects it very soon.

Dear Reid: Any other future products you can tell us about?

My Extension friends are really anticipating BASF’s Kixor, which is expected to be available in 2010. Some of them have already had the opportunity to test it. Kixor utilizes saflufenacil as its active ingredient and can be used alone or tank-mixed with glyphosate for fast burndown of weeds, including glyphosate- and ALS-resistant types, or as a preemergence treatment in corn. Hager says to expect the soil-applied PPO inhibitor to be pre-mixed with Outlook in corn and Pursuit in soybeans.

Another product I’m hearing a lot about is Bayer’s Capreno, which contains Laudis plus thiencarbazone plus a safener for postemergence broadleaf and grass control in corn. That might be available in 2010.

Bayer also has a preemergence premix containing thiencarbazone-methyl plus Balance plus a safener for corn that could be approved in 2009. The company also has a couple other new active ingredients, tembotrione and pyrasulfotole, that are scheduled for U.S. launch in the near future.
Boerboom says he heard DuPont Crop Science is bringing Steadfast Q and Accent Q to the market in 2009. Both are safened versions of existing products. He also heard that Syngenta may get its Flexstar GT, containing Flexstar and glyphosate, approved in 2009.

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