By Larry Steckel
Quite a few calls continue to come in now on many weed control issues in wheat.
In most cases where bluegrass was a problem, it became established before or with the wheat. One good option is to apply Sencor at 3 to 4 oz/A post emergence over the wheat that is at 2 to 4 lf. This timing of a Sencor application has been a very inexpensive way to manage bluegrass and just establishing broadleaf weeds like henbit.
Another very common call has been on henbit that escaped a tillage or Gramoxone application and is now actively competing with the seedling wheat crop. Sencor can provide some good control. Other options at this stage would be Finesse, Osprey or PowerFlex. All three of them should provide control of henbit at this stage plus remove most other "junk" broadleaf weeds as well a ryegrass. All three of these herbicides will suppress Poa some with Finesse providing the most suppression.
A number of questions have been asked about Finesse herbicide. Last year Finesse replaced Osprey as the main go-to herbicide for many wheat acres in Tennessee. It performed well particularly applied in the fall controlling ryegrass, many broadleaf winter annuals and even small bluegrass. There are couple things to keep in mind when using this product.
First there are two Finesse formulations. Finesse Cereal and Fallow which contains chlorsulfuron and metsulfuron (Ally). This formulation goes out at 0.5 oz/A preplant/preemergence and 0.4 oz/A postemergence. The other formulation is called Finesse Grass and Broadleaf and contains chlorsulfuron and flucarbazone. It can only be applied postemergence at a rate of 0.6 to 0.9 oz/A.
We had some issues in the past where applicators were confused and applied the Finesse Cereal and Fallow at the Finesse Grass and Broadleaf rate which resulted in some sever wheat stunting. The other thing to keep in mind is that STS soybeans are the only varieties that can be double cropped after either one of these Finesse applications are made. Be sure to have some STS soybeans lined up for double crop before utilizing this herbicide.
If securing STS soybeans is a concern then Osprey or PowerFlexHL are good options. Osprey is applied at 4.75 oz/A with 0.5% NIS plus spray grade ammonium sulfate (AMS) or 32% nitrogen solution. PowerFlexHL is a new formuation of PowerFlex and should be applied at 2 oz/A. These two herbicides similar to Finesse will control ryegrass and most broadleaf weeds like henbit. Of the two PowerFlex is the best on garlic. Axial XL has also performed well controlling ryegrass. It will not provide any control of bluegrass or broadleaf weeds. Axial XL is a new formulation with the surfactant included that is to be applied at 16.4 oz/A.
Steckel is the University of Tennessee Extension wed specialist.