Tendovo--New Tri-Mix Herbicide from Syngenta
The battle to control weeds in Midsouth soybean fields is never-ending. At this time, producers’ best weapon against them is the stable of present and forthcoming herbicides that private companies continually supply for the battle.
It is well known that 1) new herbicide chemistries are essentially non-existent, 2) the best weapon against present and future herbicide-resistant (HR) weeds is to use mixtures that contain herbicides with multiple modes of action, and 3) the use of residual or PRE herbicides should be an integral part of a weed management program for soybeans.
Syngenta has announced the US-EPA registration of Tendovo PRE soybean herbicide (click here for label). Tendovo is a premix of S-metolachlor (Group 15), Metribuzin (Group 5), and Cloransulam-methyl (Group 2) herbicides, which are marketed individually as Dual Magnum, Sencor, and FirstRate, respectively. This new herbicide may be applied preplant surface or incorporated, and preemergence.
As with all herbicides that are applied for weed management, weed species that are anticipated to be present in a field should be determined through scouting and knowledge of field history so that this herbicide will be applied where infestations of weeds that are labeled for control are anticipated. The Tendovo label provides an extensive list of both grass and broadleaf weeds that should be controlled by this herbicide.
Due to the sensitivity of some soybean varieties to metribuzin, exercise caution when selecting varieties that will be planted in fields where Tendovo will be applied. Click here for sensitivity ratings to metribuzin of soybean varieties commonly grown in the Midsouth. Also, application rates of this herbicide will need to be tailored to soil texture and soil organic matter content of individual fields. Consult the label for these varying rates. Note that this herbicide will result in crop injury if applied to soybeans that have emerged.
Another herbicide, Matador-S from Loveland Products, is a tri-mix of S-metolachlor (Group 15), Metribuzin (Group 5), and Imazethapyr (Group 2, trade name Pursuit). Thus, Tendovo and Matador-S differ in their Group 2 component, but otherwise they are equal relative to mode of action. Consult the label for each herbicide and a knowledgeable weed science professional to determine if the weeds that are controlled differ between these two herbicide tri-mixes. (This information about Matador-S is likely moot since it is not widely available or is unavailable in Midsouth states.)
The development/registration of Tendovo is important for Midsouth soybean producers since 1) it provides residual control of morningglory species in addition to many other problematic grass and broadleaf weeds, and 2) it is the only available tri-mix with the most effective Groups 2, 5, and 15 active ingredients. Producers are encouraged to become aware of how this new herbicide premix might benefit their weed management programs in Midsouth soybean fields.
Composed by Larry G. Heatherly, Mar. 2022, larryh91746@gmail.com