Managing Wheat Streak Mosaic Disease By Eliminating The Green Bridge
September 7, 2022 | View PDF
If you are preparing to plant winter wheat soon, it is important to consider green bridge control to prevent wheat streak mosaic (WSM). Wheat streak mosaic is a viral disease that impacts small grains, including spring wheat and winter wheat, as well as durum, barley, oats, and corn, among other crops. Symptoms of WSM include yellow streaking and mottling, which usually affects the entire plant. Early infections lead to plant stunting. Wheat streak mosaic impacts can range from insignificant up to 100% yield loss.
This viral disease is transmitted by the wheat curl mite. The wheat curl mite, along with the WSM virus, survive on the green bridge in between crops. The green bridge is the presence of any green plant material between the harvest of one crop and the planting of the next. Green bridge hosts of WSM virus include volunteer wheat, corn, as well as cheatgrass. Having these hosts in your area increases the risk for WSM, as wheat curl mites can travel several miles in the wind. Because of this, termination of the green bridge is key. Herbicide options include glyphosate and paraquat. Glyphosate can take up to 2 weeks as it kills slowly, causing the plants to be a host for the wheat curl mites for those 2 weeks following an application. Paraquat is fast acting and reduces the time that wheat curl mites can survive on those plants to 2 to 5 days. Tilling and swathing are also options to eliminate the green bridge and wheat curl mite populations in just a few days.
If you have any questions, contact the MSU Richland County Extension Office at 406-433-1206 or [email protected]