New herbicides aim to tackle problem and resistant weeds

SAN ANTONIO, Texas — Farmers will soon have access to herbicides containing new active ingredients to help combat the mounting problem of herbicide tolerant weeds.


“We don’t see new active ingredients come along very often anymore,” said Scott Cully, research and development scientist with Syngenta Crop Protection Inc.


“Usually we’re trying to make new premixes of existing things.”


Syngenta announced Acuron, a new corn herbicide, at the 2014 Commodity Classic conference. It is a herbicide premix with four active ingredients including the new bicyclopyrone, which is still under review by regulators in the United States and Canada.


“We’re expecting full registration by December of this year, and we’re expecting to have that in time to have a 2015 launch in the U.S.,” Cully said during an interview at the conference.


Harold Wright, biological assessment manager for Syngenta Canada Inc., said the company is also pursuing registration of the product in Canada but has not yet developed commercialization plans for the Canadian market.


Acuron is a broad-spectrum pre-emergence herbicide that can be applied from 28 days before planting to 12-inch high corn.


“It’s going to control all of your grasses and your broadleaves, including many of the difficult-to-control broadleaf weeds,” said Cully.


The herbicide will handle resistant weeds such as giant ragweed, common ragweed, marestail, kochia, Palmer amaranth, waterhemp, cocklebur and morning glory.


“It will control any of the herbicide tolerant weeds except for HPPD tolerant weeds,” said Cully.


The other active ingredients in the product are atrazine, mesotrione and s-metolachlor. Acuron contains three modes of action for group 5, 15 and 27 herbicides.


Dow AgroSciences will also soon have a new active ingredient on the market for controlling broadleaf weeds in wheat and barley crops.


Arylex is part of the synthetic auxin, or Group 4, family of herbicides, which include 2,4-D, dicamba, quinclorac and clopyralid.


“Group 4 herbicides have stood the test of time, over 60 years of use, and there have only been 10 incidents of resistant weeds in North America,” Dow spokesperson Loralee Orr said in an email.


By contrast, there have been 150 incidents of resistance to Group 2 broadleaf herbicides and even six confirmed cases for Group 27, the most recent mode of action introduced for cereal crops in Western Canada.


Arylex will be effective at a low dose rate of two grams per acre, which is significantly lower than other Group 4 herbicides. It can be applied under hot, cold, dry or wet conditions and is safe and effective over a wide range of crop and weed stages.


The product was submitted for approval in September 2012 but is not yet registered or available for purchase. It will be marketed as Pixxaro and Paradigm, which will be made from a combination of Dow active ingredients.


“Both of the new products will have a strong fit in the black soil zone of Western Canada in wheat and barley,” said Orr.