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There are no new modes of action available, but be aware of these reformulations.

February 4, 2021

5 Min Read
sprayer in field
KNOW THE CHANGES: Most new herbicide products on the market for the coming growing season are simply new premixes or revised formulations of existing active ingredients. Still, it’s good to know what changes are out there.Leonid Eremeychuk/Getty Images

There are no new herbicide modes of action on the market for this coming growing season. All the newer herbicide products are simply new premixes or revised formulations of existing active ingredients.

Nonetheless, here are several products, label updates and products in the pipeline to consider:

Syngenta product changes

Syngenta is modifying Acuron, Acuron Flexi and Halex GT.

Current formulations of Acuron and Acuron Flexi will be phased out after 2022. The new replacement products will be Acuron XR, Acuron Flexi XR, and Acuron GT. Primary changes include increased amounts of mesotrione (Callisto) and s-metolachlor (Dual) in the new formulations of Acuron XR and Flexi XR. Acuron GT is the same as Halex GT, but will contain bicyclopyrone.

The new formulations likely will not be used until the 2022 cropping season, but bulk tanks will start to be filled later this year.

Gowan has acquired the rights to the active ingredients prosulfuron and primisulfuron from Syngenta. The acquisition includes product registrations and trademarks for Peak, Spirit, Beacon and Northstar herbicides, and related intellectual property and labels.

This is good news since we typically recommend the use of Peak and Spirit to control burcucumber in corn.

Reformulations and use changes

• Authority Edge 4.25SC (sulfentrazone [Spartan] + pyroxasulfone [Zidua]; groups 14, 15; FMC) has similar active ingredients as Authority Supreme, but has a higher sulfentrazone load for use in any type of soybean. It will be soil-applied and will have activity on both annual grasses and broadleaf weeds at 7 to 9 fluid ounces an acre.

• Impact Core 7.15EC (topramezone [Impact] + acetochlor [Harness]; groups 27, 15; AMVAC) will be used post in field corn and provides foliar and some residual control of annual grasses and broadleaves. The typical use rates are 20 to 36 fluid ounces an acre.

• Kyber 2.64SC (flumioxazin (Valor) + pyroxasulfone (Zidua) + metribuzin; groups 14, 15, 5; Corteva) will be used pre in any type of soybean and provides residual control of annual grasses and many broadleaves. Typical use rates are 1 to 1.5 pints.

Fierce MTZ (Valent) contains the same ingredients and ratios.

• Perpetuo (flumiclorac [Resource] + pyroxasulfone; groups 14, 15; Valent) can be used post in any type of soybean and provides foliar control of certain broadleaf weeds and residual control of many grassy and broadleaf weeds. The use rate is 6 to 10 fluid ounces an acre.

• ProClova (florpyrauxifen (aka Rinskor active) + 2,4-D; group 4; Corteva) will be labeled for use in grass pastures and hayfields to control or suppress many broadleaf weeds such as ironweed, cocklebur, wild carrot, buttercup, biennial thistles, ragweeds, plantain, poison hemlock, dandelion, marestail, horsenettle and others.

It is safe on forage grasses and does not kill white clover. The typical rate will likely be 1.5 pints an acre.

It has no grazing restrictions and does not have issues with herbicide residues in manure and hay like Milestone or GrazonNext products. ProClova is not yet registered but has an anticipated launch in 2021.

• Reviton 2.83SC (tiafenacil (aka Tergeo); group 14; Helm) can be used in a burndown program before field corn, soybean or wheat.

Corn or wheat can be planted immediately after application. Wait 14 days to plant soybeans and at least four months to plant other crops. It has a low use rate (1 to 3 fluid ounces an acre) and can be tank-mixed with other herbicides such as glyphosate to broaden the control spectrum.

MSO or COC, plus AMS must be added to the spray solution for effective control. Reviton is like Sharpen and will compete with it for market share, but it is less active on marestail with better grass control than Sharpen.

• Roundup PowerMax3 (Bayer) is a new, high-load (4.8 pounds an acre), unique adjuvant glyphosate formulation.

PowerMax3 at 19 fluid ounces equals 22 fluid ounces of PowerMax (0.75 pounds an acre).

• Shieldex 3.33SC (tolpyralate; group 27; SummitAgro) is a new low-use rate (1 to 1.35 fluid ounces an acre) HPPD herbicide that controls annual grasses and broadleaves postemergence in field and sweet corn. It is very similar to Armezon or Impact, and will typically be tank-mixed with atrazine to improve the control spectrum.

• Sinate 2.57L (topramezone [Impact] + glufosinate [Liberty]; groups 10, 27; AMVAC) can be used postemergence in field corn and sweet corn varieties that have the LibertyLink trait and controls many annual grasses and broadleaf weeds. Typical use rates are 21-28 fluid ounces an acre.

Paraquat updates

Anyone using products containing paraquat (Gramoxone and all other generic formulations) must now complete an EPA-mandated training before application. Here are some important points:

  • Only certified applicators, who successfully completed the paraquat-specific training, can mix, load or apply paraquat.

  • Application “under the direct supervision” of a certified applicator is no longer allowed. Registered technicians cannot apply.

  • Restricts the use of all paraquat products to certified applicators only.

  • Applicators must repeat training every three years.

The EPA website has the required training. For those who are unable to do the training online, EPA will have a non-web-based training format available.

Refer to the EPA paraquat website for more information and frequently asked questions.

In addition to the training, EPA requires that paraquat products be contained in a closed system. Over the next year or so, manufacturers will begin placing special lids on 2.5-gallon jugs and a necessary adaptor/receptacle will need to be installed on your sprayer in order to pour this herbicide into the sprayer tank.

These new jug caps cannot be removed or opened by hand. Mini bulk tanks will also have special connectors on hoses to maintain a closed system into the sprayer tank. More details will be released once these lids and adaptors become more widely available.

Lingenfelter is a weed science Extension associate with Penn State Cooperative Extension.

Source: Penn State Cooperative Extension, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.

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