Mark VanGessel, Extension Weed Specialist; firstname.lastname@example.org
Metribuzin is a product used for years in soybeans and other crops for broadleaf weed control (formerly called Sencor or Lexone). It has been labeled for use in winter wheat, but the label does not recommend its use in our region. Metribuzin is one of the active ingredients in Axiom, and so it has been used on a limited basis in our region. Since metribuzin is a generic product there are different products available, but most go by the name metribuzin or some close version of this spelling.
After identifying ALS-resistant chickweed and looking for potential control options I began testing metribuzin, along with a number of other weed specialists in the region. We have had good results with control and very little injury with metribuzin.
The label reads, “metribuzin alone or with tank-mixture treatments are recommended for use in the following states” and none of the states in the Mid-Atlantic region are included. On the other hand, the label does not prohibit the use of metribuzin. Metribuzin label does allow for tankmixing herbicides, to broaden the spectrum of control. We have not tested all the possible combinations with newer herbicides (Axial XL, Osprey, or PowerFlex).
Rate is dependent on soil type and growth stage. Application timing is from 2-leaf stage of the wheat until 4 tillers. We have tested metribuzin primarily for ALS resistant common chickweed, and rates of 2 to 4 oz applied with a nonionic surfactant have worked quite well.
Some precautions on the label include: Do not apply to stressed crop (including dormant, drought, frost damage, disease); do not apply with liquid fertilizer; do not use on soils with less than 0.75% organic matter; do not apply more than 0.5 inches of irrigation for the first irrigation after application and do not exceed 1 inch for any subsequent irrigation; wheat varieties differ in sensitivity (some are more sensitive than others).
Metribuzin is also labeled for barley, but we do not have experience with it.