Mark VanGessel, Extension Weed Specialist; mjv@udel.edu
As preemergence herbicide use increases, more metribuzin applications are being made. Metribuzin is sold under a number of generic names including Tri-Cor and Glory. Metribuzin is a component of Canopy, Authority MTZ, Boundary, and Trivence. Metribuzin provides effective control of a wide range of broadleaf weeds, including common ragweed and Palmer amaranth. One concern raised about metribuzin is crop safety. UD Research has tested metribuzin for years at rates of 3 to 4 oz wt/A had have not seen issues with safety. We know in situations with overlaps or compacted soils, the risk of injury increases. Another variable is soybean variety. Many of the varieties listed on the metribuzin labels are no longer grown in this area. The University of Arkansas has tested numerous current soybean varieties for tolerance to metribuzin and that information is available at http://www.arkansas-crops.com/wp-content/uploads/2016/12/2016-Metribuzin-Tolerance-of-Soybean-Varieties-FINAL1.pdf