3 Scouting for Weeds

    Weeds in small grain reduce yield and quality. A weed control program should involve:
1. Good seedbed preparation.
2. Effective fertilization.
3. Planting grain free of weed seed and garlic.
4. Seeding at the proper time and rate.
5. Herbicide applications when needed.
    The most serious weeds in small grains are winter annuals that germinate in the fall or early winter and perennials such as wild garlic and curly dock. Winter annuals include broadleaf weeds and annual (Italian) ryegrass. Many of the weeds found in small grains are described and pictured in Identifying Seedling and Mature Weeds Common in the Southeastern United States (your local Cooperative Extension office can tell you how to obtain this book).
If the soil is moist, winter annual usually germinate soon after emergence of the small grain. Inspect fields in the fall and early winter and identify the various weeds present. The weed spectrum will determine the herbicide rate and whether or not a tank-mix of two herbicides is needed for control. Since small grains differ in their sensitivity to herbicides, it is critically important to apply at the lowest effective rate. Phenoxy herbicides for broadleaf weeds are applied to small grains in the fully tillered stage before plants begin to joint.
Curly dock and wild garlic are the principal perennial weeds found in small grains. They require higher phenoxy herbicide rates for control. Treat when grains are in the fully tillered stage. A new herbicide has proven to be more effective on wild garlic control and can be applied in wheat from the two-leaf stage to detection of flag leaf, and in barley from the two-leaf stage but before the first node is detectable. This herbicide also controls several winter annual broadleaf weeds and curly dock.
Make a decision to apply a herbicide to control Italian ryegrass on the basis of previous knowledge of infestations and examinations of the field for 6 to 8 weeks following planting. Only wheat may be treated preemergence. Wheat and certain barley cultivars may be sprayed after emergence to the fully emerged stage when the ryegrass is in the two- to five-leaf stage. However, the herbicide rate increases with an increase in number of ryegrass leaves. Wheat yields are reduced 4.2 percent for every 10 ryegrass plants per square yard.