Cool-season grass weeds like bluegrass and brome grass have increasingly become problematic for wheat, barley, and small grain forages. But these pesky weeds aren’t just limited to grain fields—they can also invade grass and legume hay fields. When soil temperatures drop below 70°F, expect germination to begin. Effective fall management is key to safeguarding your crops and ensuring strong growth next spring. Here’s what to keep in mind when managing cool-season grass weeds in wheat, barley, and hay fields:
1. Scout Early and Often
Monitoring your fields before planting is crucial. Scout for weed pressure even before you harvest your corn and soybeans, and continue through the fall planting season. Early identification and action can significantly improve the success of your control measures. Learn more about crop scouting services in Shillington, PA.
2. Delay Planting and Use Burndown Herbicides
While it’s common practice to plant cereal grains early (late September to early October) for optimal stand establishment, delaying planting 7-10 days after summer crop harvest can help combat cool-season grasses. This delay allows these weeds to germinate so they can be effectively terminated with a burndown herbicide at planting.
3. Adjust Forage Mixes
If you add annual ryegrass to triticale and rye for small grain silage, be aware that post-emerge herbicide options are even more limited when cool-season grass weeds are present. Adjust your forage mixes accordingly to manage these challenges.
4. Herbicide Options for Established Hay Fields
- Alfalfa: Pure legume crops are easier to manage when it comes to post-emergence herbicide applications. Herbicides like Clethodim (Select), Quizalofop (Assure II), and Sethoxydim (Poast) can be applied to control grass weeds.
- Mixed Alfalfa and Grass Hay: Post-emerge herbicide options are limited. However, Pendimethalin (Prowl H2O) is a viable option for pre-emergence control. Apply it in single or sequential applications within 30 days of each other, but remember—apply before grass germination! If the grasses have already emerged, it may be too late. Timing your application immediately after harvesting a fall cutting can help limit fall weed emergence.
Always refer to the label and consult your trusted chemical advisor before applying any herbicide.
5. Managing New Seeding Hay Fields
Fall-planted hay fields can be treated similarly to cereal grains. Delaying planting allows cool-season grasses to germinate, which can then be terminated with a burndown herbicide. Successful alfalfa fields were established well into September, and grass hay fields were planted as late as the first week of October. Start your fields off clean by following this strategy.
Taking action this fall is essential to prevent a weed nightmare next spring. Scout early, apply herbicides at the right time, and adjust your planting strategies to keep your fields weed-free and productive! Remember, you can contact Rosetree Consulting in Shillington, PA, to manage cool-grass weeds.
