Many producers in Tennessee are utilizing metribuzin (Sencor/Lexone/Tricor/etc) pre emergence in their soybeans to help control Palmer amaranth.  Metribuzin is a PSII inhibitor (Group 5) herbicide that provides residual control of a number of annual grasses and broadleaf species. Metribuzin is especially effective as a soil-applied residual when used in combination with other herbicide modes-of-action such as the products Authority MTZ, Boundary, and Canopy to name a few.

A potential problem with the use of metribuzin in soybean is that some varieties are more prone than others to incur injury from this herbicide. Other factors like soil texture, organic matter content, rainfall, and product use rate, will also come into play in the probability of soybean injury from the use of metribuzin.

In order to give soybean producers a heads up on the relative sensitivity of current soybean varieties our colleagues at Mississippi State and the University of Arkansas in 2011 and the University of Arkansas in 2012 screened many of the more commonly planted soybean varieties in the Mid-South.  This information can be accessed with the links below:

UA/MSU: Metribuzin Tolerance Testing of Soybean Varieties-2011

UA: Metribuzin Tolerance Testing of Soybean Varieties-2012