By Dwight Lingenfelter
Dense populations of winter annual weeds can compete with wheat and barley in late fall and early spring and slow the rate of crop development potentially reducing yield. If winter annual weeds like common chickweed, henbit, winter annual grasses, and others emerge with the small grain and are left unchecked, the potential impact on yield could be great. In these situations, it may make sense to kill these weeds in the fall rather than early spring.
Harmony Extra is the most broad spectrum herbicide for broadleaf control, but resistant populations of common chickweed are becoming evident in parts of the state. In addition, there are several herbicides labeled for grass control in wheat and fall is typically the best time to make an application. Make sure to include the necessary spray adjuvants. Remember that cool (less than 50 oF) cloudy days can reduce herbicide activity. Also, if you plan to frost-seed or drill a companion crop such as red clover in early spring it may be best to make a fall herbicide application to avoid certain issues with herbicide residuals affecting their establishment. However, even if products such as PowerFlex HL, Osprey, Glory and others are applied in the fall, their recrop restrictions still prevent seeding next spring. The following table summarizes some fall herbicide options for small grains. Check a current herbicide label for the latest use information.
Common Fall Herbicide Options
| Herbicide | Crops | Strengths | Growth stage | Remarks, if any |
| 2,4-D | Wheat, barley, rye | Horseweed, mustards, dandelion | 3–6 | |
| Aim | Wheat, barley, oats | Star-of-Bethlehem, speedwell | 1-5 | |
| Anthem Flex | Wheat | Annual grasses and broadleaves | delayed pre to early post | Does not control emerged weeds; suppression only of chickweed and horseweed |
| Axial XL | Wheat, barley | Annual/Italian ryegrass | 2–8 | No control of ACCase-resistant species |
| Clarity/Banvel | Wheat, barley | Horseweed, thistles | 3–6 | |
| Glory | Wheat, barley | ALS-resistant chickweed | 1–4 | Controls winter annual broadleaves |
| Harmony Extra | Wheat, barley | Most broadleaves, garlic | 1–7 | Will not control ALS-resistant chickweed |
| Huskie | Wheat, barley, triticale | Most broadleaves | 1–7 | Has good activity on marestail/horseweed |
| Maestro (Buctril) | Wheat, barley, rye | Mustards | 1–9 | |
| Maverick | Wheat | Downy brome, cheat, chess | 1–5 | Controls some broadleaves, watch recrop restrictions |
| MCPA | Wheat, barley, rye | Same as 2,4-D | 3–6 | |
| Osprey | Wheat | Annual/Italian ryegrass, annual bluegrass | 1–5 | Controls some broadleaves |
| Peak | Wheat, barley, rye, triticale | Mustards, garlic | 2–6 | Watch recrop restrictions |
| PowerFlex HL | Wheat | Downy brome, cheat, annual/Italian ryegrass | 3-leaf to 6 | Controls some broadleaves; will not control ALS-resistant chickweed |
| Prowl H20 | Wheat, triticale | Annual ryegrass, downy brome, some annual broadleaves | 1-7 | Apply after small grain emergence but before weeds have emerged |
| Starane Ultra | Wheat, barley | Chickweed (including ALS-resistant) | 2–9 | |
| Stinger | Wheat, barley | Thistles | 2–9 | Watch recrop restrictions |
| Sharpen | Wheat, barley, oats, rye, triticale | Annual broadleaves | before crop emergence | Controls existing horseweed |
| Valor SX | Wheat | Annual broadleaves | 7-days early preplant | Improves horseweed control; plant wheat at least 1" deep |
| Zidua | Wheat | Annual grasses and broadleaves | delayed pre to early post | Does not control emerged weeds; suppression only of chickweed and horseweed |