Some Herbicide Considerations For Wheat And Barley

William Curran
Dwight Lingenfelter

Here is a brief summary of what’s available for small grains.

Over the last few years, several residual herbicides can be used in wheat and sometimes barley. These herbicides are labeled either preplant or perhaps early postemergence. Here is a brief summary of what’s available for this type of application.

Axiom (Bayer) has had a label for several years mostly focused on Italian ryegrass control in wheat. We have not had much experience with this. Axiom is a mixture of flufenacet (grass herbicide) plus metribuzin. The specifics are to plant wheat 1-2 inches deep and make the application after the crop has fully germinated up to 2 leaves emerged. Spike to 2-leaf is the ideal timing. Axiom will not control emerged weeds. The rate for medium textured soils is 6 to 8 oz Axiom DF per acre.

Prowl H2O (BASF) can be applied after wheat emergence at up to 3 pt/acre. Apply once the wheat rows are visible (row and go) and before weeds have emerged or include a POST herbicide with Prowl. Prowl will provide residual control of a number of winter annual weeds.

Sharpen (BASF) may be applied preplant or preemergence at up to 2 fl oz/acre to wheat, barley, rye, and triticale. In addition, Sharpen received a supplemental label for up to 4 fl oz/acre for enhanced burndown and residual control in wheat only. In our region, Sharpen should help manage horseweed (marestail) and will provide some residual control of susceptible species such as ALS-resistant chickweed and other winter annual broadleaves.  Do not apply after small grain emergence.

Valor (Valent) has a 30-day “early preplant” burndown/residual label for wheat. Valor can be applied at 1 to 2 oz/A with labeled burndown herbicides and a minimum of 30 days must pass plus 1 inch of rainfall between application and planting. Valor applied at this time should provide residual control of fall emerging winter annuals, but not spring. Interestingly, Valor is labeled at up to 2 oz/A on the Delmarva (DE, MD, NJ, and VA), 7 days or more ahead of no-till wheat planted at least 1 inch deep. This supplemental label does not include PA.

Zidua (BASF) received a supplemental label for delayed PRE or early postemergence in winter wheat. For delayed PRE, apply Zidua to a uniform firm seedbed making sure seed is well covered. Apply Zidua when wheat shoots are at least ½-inch long to spiking (also row and go). Zidua may be applied early POST up to 4-tillers, but it will not control emerged weeds. The use rate is 1 to 1.25 oz/acre delayed PRE on medium soils or generally 1.5 oz/acre Early Post for no more than a seasonal maximum of 2.5 oz/acre when applied sequentially (keep in mind that we generally use 2.5 oz/acre in corn and soybean). Zidua should be quite effective on Italian ryegrass as well as other annual grass species and some winter annual broadleaves. Mark VanGessel at the University of Delaware had a trial this last year in wheat where he reported positive results with Zidua on jagged chickweed (relative of common chickweed), henbit, and Italian ryegrass.

Source : psu.edu