The soil has been disked, the seed planted, and a good rain came to get the winter wheat established. Yet, a farmer's work is never done, and less than a month after the seed went into the ground, the next challenge is here: ryegrass.
Flowering ryegrass in a field of wheat. Photo courtesy of Texas A&M.
Ryegrass (Lolium multiflorum) is a cool-season broadleaf annual that was originally introduced to Northeast Texas to provide winter grazing for livestock. When taken by itself, ryegrass can be beneficial both as forage and as a cover crop to stabilize the soil. However, when it germinates in a field of winter wheat, its high adaptability and competitiveness can be damaging to the crop.
Control Methods
The primary control method for ryegrass is to disk it or cut it for hay before it goes to seed. However, this does not typically control 100% of the grass, and if ryegrass is found in the field after wheat planting, options for control are limited. The conventional control recommendation is application of a selective herbicide. Unlike other major row crops such as corn and soybeans, wheat does not have genetically modified varieties that are protected from broad-spectrum herbicide application. This means that any herbicide used has to be selective such that application terminates the ryegrass without terminating the wheat.
Markets
Why does this matter? The main reason is found in the conventional markets available for selling wheat grain. When grain is delivered to an elevator, it is inspected for quality to determine the price it can demand. Wheat will be "docked" based on the percentage of ryegrass it contains, then "docked" again for its percentage of foreign matter, which also includes ryegrass. Ryegrass, therefore, is a double negative in the conventional wheat market, significantly reducing how much the farmer is paid for his harvest.
This year's winter wheat shown in the three rows with ryegrass mixed in between. The ryegrass are the thin blades of grass between rows of wheat.
This is just one example of the challenges with farming and the conventional solution. It highlights the importance of developing regional solutions accounting for the soil's history and type, local climate, and regional markets available for selling the harvested crop. The most important of these is the availability of markets, which gets to the topic of the agricultural supply chains that exist at global, national, regional, and local levels. Understanding and creating these markets is a constant challenge for farmers and one that will be addressed in upcoming blog posts.
References:
Texas A&M - An IPM1 Approach to Managing Herbicide Resistant Ryegrass in Northeast Texas
Texas A&M - Weed Control Recommendations in Wheat
Washington State University - Wheat and Small Grains