New herbicide technology for 2017

Each year, agricultural chemical companies roll out “new” herbicides for managing weeds in corn and soybeans.

In reality, the only truly new products are the herbicide premixes themselves. They’re herbicides with existing sites of action joined together. The last truly new herbicide site of action for corn and soybeans came in the form of the HPPD inhibitors (Callisto, Corvus, Balance Flexx) that started to be commercialized in the late 1990s. Instead, the industry has shifted from developing herbicides with new sites of action to traits that enable crops to tolerate herbicides with existing modes of action.

However, premixes do help broaden weed control spectrums. Label changes also come along each year, too. Here’s a list of what’s new in weed management products for the 2017 growing season rounded up by Mike Owen, Iowa State University Extension weed specialist.

Dicamba Tolerance

Monsanto’s dicamba-tolerant herbicide system will fully debut in 2017. Although federal regulators in 2016 approved soybean varieties in Monsanto’s Roundup Ready Xtend Crop System that tolerate dicamba and glyphosate, they didn’t approve matching dicamba formulations.

That’s changed. Federal regulators have approved Monsanto’s Xtendimax with VaporGrip. Vapor Grip is an additive that reduces volatilization. At this time, the label is restricted such that not tankmix combinations are allowed and only one nozzle is registered to be used when applying Xtendimax with VaporGrip Technology. (For more information, go to https://www.monsanto.ca/products/Documents/XtendiMax%20with%20VaporGrip%20Label.pdf )

Also approved is BASF’s Engenia, another dicamba formuation that is lower in volatility than existing ones. Company officials say Engenia has 70% lower relative volatility when compared with Clarity, an existing dicamba formulation. The Engenia label at this time also restricts tankmixes and nozzle selection. (For more information on Engenia, go to http://www.cdms.net/ldat/ldDG8005.pdf )

DuPont will market its own brand of dicamba with Vapor Grip technology called FeXapan, through an arrangement with Monsanto. The Environmental Protection Agency (EPA) registration for FeXapan is in the works and is expected any day now, say company officials.

Monsanto also has developed another herbicide for its dicamba-tolerant system that hasn’t yet received federal approval. Roundup Xtend is a premix of glyphosate and a low-volatile formulation of dicamba.

Other Herbicide-Tolerant Systems

Enlist Duo is registered and available for non-Enlist corn and soybean as preplant burndown and preemergence (corn) and preplant burndown (soybeans) but not available for postemergence use until crops in the Enlist Weed Control System are approved by China. No adjuvants are described on the Enlist Duo label.

Enlist Duo has less potential for volatilization than new dicamba formulations. However, Owen advises applicators to avoid conditions that may cause off-target movement. The Enlist Duo label describes appropriate nozzles for application, buffer requirements, and specific application techniques. Herbicide-resistant weed management requirements are also included in the Enlist Duo label.

Bayer Crop Science has had its Balance GT Soybean Performance System in the works for several years. This system includes a trait that confers tolerance to glyphosate and isoxaflutole, the active ingredient in the new Balance® Bean herbicide. Corn farmers have used isoxaflutole for years in herbicides like Balance Flexx and Corvus.

The Balance GT trait has received all necessary import approvals from foreign customers. However, the system won’t be commercially available until Balance Bean herbicide receives EPA approval. Collaborating companies expect EPA approval to occur, but a full-scale launch likely won't occur until 2018. http://www.agriculture.com/crops/soybeans/companies-hopeful-for-2017-launch-of-balance-gt-soybeans

Zidua Pro

BASF’s Zidua Pro contains pyroxasulfone that belongs to herbicide group (HG) 15. It also contains imazethapyr (HG2), and saflufenacil (HG14). Zidua Pro is also labeled for burndown and preemergence uses in soybeans at rates of 4.5 to 6.0 fluid ounces per acre. Optimal burndown of emerged weeds requires the use of MSO and a nitrogen source.

No planting interval restriction is listed for Zidua Pro except when applications are made on coarse-texture soils with less 2% organic matter where a 30-day interval between application and planting is required.

In other BASF products, a preemergence application is now available for Armezon Pro (HG27 and HG15) label for corn. Zidua’s (HR15) postemergence application window in soybeans has been expanded to allow treatment from emergence to third trifoliate stage.

DiFlexx Duo

Bayer CropScience obtained registration of DiFlexx Duo for field, white, seed, and popcorn in spring 2016. DiFlexx Duo combines tembotrione (HG27), dicamba (HG4), and the safener cyprosulfamide. DiFlexx Duo is registered for preemergence and postemergence (up to V10 corn stage) applications. Use rates range from 24 to 40 ounces per acre. Adjuvants needed for postemergence DiFlexx Duo applications include HSOC, COC, or MSO and a nitrogen source.

Resicore

Dow AgroSciences’ Resicore was approved in 2016 for application in field corn, seed corn, silage corn, and yellow popcorn for preemergence application. It contains acetochlor (HG15), mesotrione (HG27), and clopyralid (HG4). Resicore may be applied postemergence to field corn, seed corn, and silage corn but not yellow popcorn. Postemergence applications must be made before corn is 11 inches high.

DuPont’s Realm Q and Afforia

DuPont’s Realm Q (HG2 and 27) is now registered for aerial application, and dicamba (HG 4) has been added as a tank mix partner. Aerial application of HG27 and HG4 herbicides represents a potentially serious risk for off-target herbicide movement, says Owen.
Afforia can be applied either preplant or preemergence to any soybean at 2.5 ounces per acre. Preemergence applications must be made within three days after planting and prior to emergence. When used with Bolt soybean varieties, the Afforia rate can be increased to 2.5 to 3.75 ounces per acre for either preplant or preemergence applications. The Bolt technology provides enhanced tolerance to sulfonylurea herbicides (HG2).

Nufarm’s Cheetah, Panther SC and Scorch

Cheetah contains glufosinate ammonium (HG10) and is registered for non-selective postemergence application in corn and soybeans with the LibertyLink trait.

Panther SC is a 4-pound-active-ingredient-per-gallon formulation of flumioxazin (HG14). It’s registered for preplant burndown application in corn three to 30 days prior to planting. Panther SC can be applied prior to soybean planting or preemergence within three days after planting and prior to soybean emergence.

Scorch is a premixture of dicamba, 2,4-D, and fluroxypyr, all HG4 herbicides. It can be applied preplant, preemergence, and postemergence in field corn. Fluroxypyr improves activity on kochia. Postemergence applications of Scorch can be broadcast to V5 or 8-inch-high corn. Applications made from V6 to 36-inch-high corn (or 15 days prior to tasseling) must be made with directed drop nozzles.
 
Acuron Flexi

Syngenta’s Acuron Flexi is a premixture of bicyclopyrone (HG27), mesotrione (HG27), and S-metolachlor (HG15). It is registered for preplant, preemergence, and postemergence application in field corn, seed corn, and silage corn. Sweet corn and yellow popcorn cannot be treated with Acuron Flexi.