Effective Mustard Weed Management Boosts Crop Yields

By Scout Nelson

Kansas State University's Sarah Lancaster advises producers to be careful in controlling mustard weeds, which can significantly impact crop yields. Mustards, part of the brassica family, have two growth phases: a ground-level rosette stage and a flowering phase, which can be difficult to spot without thorough field inspection.

Effective control of these weeds involves good scouting practices and choosing the right weather for herbicide application. Mustard weeds, which can be yellow, white, or purple, are known for their high sulfur content, often resulting in a strong odor.

Common mustard plants include canola, shepherd’s-purse, field pennycress, bushy wallflower, pinnate tansymustard, blue mustard, and wild mustard. Lancaster advises farmers with a history of mustard weed issues to regularly walk their fields for early detection.

The best time to spray mustards is during their rosette phase, where the increased leaf surface area allows for better herbicide absorption. Lancaster recommends using Group 4 herbicides like 2,4-D, which are more effective than dicamba in controlling mustard species. Caution is advised when using 2,4-D in the fall to ensure that wheat is fully tillered to avoid reduced yield potential.

Other herbicide options include MCPA, Husky, Talinor, and Group 2 ALS-inhibiting herbicides like Glean, Olympus, or Powerflex. ALS-inhibiting herbicides are susceptible to resistance development, as seen in Kansas with flixweed and bushy wallflower.

Mustard weeds can spread from various sources, including neighboring fields and roadsides. Lancaster notes that herbicides are most effective when plants can absorb them, emphasizing the need for appropriate weather conditions, especially temperature, for spraying. Ideal conditions for fall spraying are between 50-60 degrees Fahrenheit.

In addition to herbicide use, crop rotation is another effective weed control strategy. Lancaster concludes by stressing the importance of field scouting to make accurate herbicide decisions and maintain optimal crop health and yield.

Photo Credit: pexels-tom-van-dyck