By Scout Nelson
Kansas wheat fields are facing one of the worst Wheat Streak Mosaic Virus (WSMV) outbreaks since 2017. The spread is driven by wheat curl mites that carry multiple viruses, including WSMV, Triticum mosaic virus (TriMV), and High Plains Mosaic Virus.
Experts report near-total losses in some fields. Symptoms like yellow streaks and stunted plants are now more visible with warmer temperatures. However, the root cause was the high mite population last summer. These mites survived in volunteer wheat and cover crops, creating “green bridges” through mild weather, allowing them to travel up to two miles and infect many new fields.
“If we have an extended, warm fall, like we did in 2024, it’s a perfect storm for mite populations to stay at high levels and increase later in the season,” said an expert.
Fields now near flowering may show reduced grain fill and poor head development. There is currently no treatment for WSMV, and fungicides or insecticides do not help infected crops. Severely affected fields may require early termination to prevent further economic loss.
Diverse cropping, hailstorms, and repeated dry seasons have made the problem worse. Wheat varieties with some resistance to WSMV are showing better performance, though dual infections with TriMV are causing more severe yield loss.
“We do not have any perfect resistance, but variety selection is making a difference under this really high-pressure situation,” stated a plant pathology expert.
Other wheat diseases like Fusarium head blight (FHB) are also a concern in certain areas, especially during flowering. Producers are advised to monitor conditions using tools like the Fusarium Risk Tool and consult fungicide ratings.
Upcoming wheat variety plot tours beginning May 13 will help farmers evaluate which varieties can handle disease pressure. Experts stress that managing volunteer wheat after harvest is vital to preventing another outbreak next year.
Photo Credit:gettyimages-ygrek
Categories: Kansas, Crops, Wheat