What's New for Agronomic Weed Control in 2022

By Dwight Lingenfelter and John Wallace

Product/Label/Pipeline Updates

As in the recent past, there are absolutely no new herbicide modes of action. Below are some newer product premixes, revised formulations of existing active ingredients, and tradenames to consider:

Syngenta is launching Acuron GT, a new, post-emergence corn herbicide that contains bicyclopyrone, an advanced technology proven to deliver faster knockdown, enhanced control and longer-lasting residual in glyphosate-tolerant corn. While Acuron GT was available in limited supply for the 2021 season, it is expected to be widely available for use in 2022. 

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 have activity on annual grasses and broadleaves at 7-9 fl oz/A.

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 fl oz/A.

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 from1-1.5 pints/A. Fierce MTZ (Valent) contains the same ingredients and ratios.

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. We typically recommend the use of Peak and Spirit to control burcucumber in corn.

Maverick 2.04SC (pyroxasulfone [Zidua] + mesotione + clopyralid; groups 15, 27, 4; Valent) has a wide application window from pre to 18” tall corn and provides foliar and residual control of many annual grasses and broadleaves at 14-32 fl oz/A; can be tank-mixed with atrazine and other products. It will compete with products like Resicore, SureStart II, and Acuron. Its registration is expected by possibly early 2022.

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 broadleaves. Use rate is 6-10 fl oz/A.

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 24 fl oz/A. 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 is anticipated by 2022.

Resicore XL (Corteva) is a reformulation of Resicore for better handling, mixing, and crop safety when applied post. It can be used in field and sweet corn. Likely market launch by 2023.

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 soybean and at least 4 months to plant other crops. It has a low use rate (1 to 3 fl oz/A) and can be tankmixed with other herbicides. MSO or COC plus AMS must be added to the spray solution. Reviton is similar to Sharpen and is less active on marestail but has better activity on field pansy/violet, primrose, grass compared to Sharpen.

Roundup PowerMax3 (Bayer) is a new, high load (4.8 lb ae), unique adjuvant, glyphosate formulation. PowerMax3 at 19 fl oz = 22 fl oz of PowerMax (0.75 lb ae/A).

Shieldex 3.33SC (tolpyralate; group 27; SummitAgro) is a newer, low use rate (1 to 1.35 fl oz/A), HPPD-herbicide that controls annual grasses and broadleaves postemergence in field and sweet corn. It is very similar to Armezon or Impact. It will typically be tankmixed with atrazine to improve control spectrum. Restraint 6.5EC is a premix of the active ingredients in Shieldex and Harness and provides foliar and some residual control of annual grasses and broadleaves at 30 to 48 fl oz/A and will compete with Impact Core for market share.

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 to 28 fl oz/A.

Tendovo 4.14ZC (s-metolachlor [Dual Mag.] + metribuzin + cloransulam [FirstRate]; groups 15, 5, 2; Syngenta) will primarily be used as a burndown product which will have some residual. It can be tankmixed with other herbicides. Its use rates will be 1.9 – 4.7 pt/A and will provide residual control of many annual grasses and broadleaves. Its registration is expected sometime in 2022.

TriVolt (isoxaflutole + thiencarbazone + safener [Corvus] + flufenacet [old Define]; groups 27, 2; 15; Bayer) can be applied from PRE to V2 corn growth stage and provides residual control of many annual grasses and broadleaves at 10 – 20 fl oz/A. Registration is still pending but is expected sometime in 2022.

Voraxor (BASF) will be a premix of saflufenacil (Sharpen) + trifludimoxazin (Tirexor) [group 14] for burndown and residual.

Paraquat updates: Anyone handling and using products containing paraquat (i.e. Gramoxone and all other generic formulations) must now complete an EPA-mandated training before application. The training must be repeated every three years. The EPA required video training is available on the paraquat training website (users must create an account with username and password). A non-web-based training format is also available. Refer to the EPA 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 upcoming years, manufacturers will begin placing special lids on jugs and tanks that require a specific adaptor/receptacle on your sprayer tank. Stay tuned for more details about these lids/adaptors.

Newer sorghum technologies

A few newer herbicide-resistant sorghum technologies coming to the market, here is a brief overview of each. Keep in mind other herbicides will need to be included to broaden the weed control spectrum.

• Double Team from S&W Seed Company is a non-GM variety and is tolerant to FirstAct from Adama which contains quizalofop for post grass control; tankmix for other weeds.
• igrowth system from Alta Seeds and Advanta is also a non-GM variety but is tolerant to ImiFlex from UPL which contains imazamox and provides post control of annual grasses and certain broadleaves.
• Inzen sorghum from Pioneer has been available for a few years is also a non-GM variety and is tolerant to Zest WDG from Corteva which contains nicosulfuron for post control of annual grasses and certain broadleaves.

Some of these are starting to be marketed in our region so check with one of these dealers for availability.

Newer soybean technologies

Xtend, XtendFlex, and Enlist E3 soybean technologies are being used more often in our area and around the country. Estimates for the 2022 growing season in our region ? Xtend and XtendFlex soybeans acres around 50% or less, while Enlist E3 acreage will increase to 50% or more. But keep in mind, these estimates can vary between states and local areas. Table 1 below compares the two systems.

Table 1. Comparison of selected application factors and herbicides in Xtend/XtendFlex and Enlist E3 soybean.

ESA (Endangered Species Act) Buffer DistanceN/A (No ESA species in PA)N/A (No ESA species in PA)

(This table is not a replacement of the product labels; refer to the Bayer, BASF, and Syngenta websites for additional information and updates. In the Enlist E3 platform, Enlist One and Enlist Duo are the only 2,4-D-containing products that can be sprayed immediately at planting and/or over-the-top. See the Enlist website for additional details. Also, keep in mind, if you apply 2,4-D post to Xtend/Flex soybean it will severely injure or kill them, the same is true if you spray dicamba on E3 soybeans.)

Correction: A previous version of this article stated that Syngenta is modifying Acuron, Acuron Flexi and Halex GT and that current formulations of Acuron and Acuron Flexi will be phased out after 2022, but we have since learned this is incorrect so we modified the article accordingly. Acuron and Acuron Flexi are available for sale and use in the 2022 season and are expected to remain in Syngenta’s corn herbicide portfolio.