Late rains and abandoned fields have elevated concerns about volunteer wheat. Hidden within these stands lurks a danger, a sanctuary for diseases like the Wheat Streak Mosaic Virus (WSMV). Aaron Harries, a research leader, emphasizes that while there's no treatment for WSMV, it's preventable.
The Kansas State Agronomy update highlighted that controlling volunteer wheat promptly is the best defense against WSMV. Volunteer wheat acts as a "green bridge", letting wheat curl mites, the carriers of WSMV, grow. It's not just isolated wheat spots that are concerning. Grass weeds like barnyard grass can also be a disease host.
Post-harvest, Kansas farmers typically delay herbicide application until enough volunteer wheat appears. But, before planting, it's important to destroy this “green bridge” using herbicides or even tillage. Wet late summers can spur multiple growths of volunteer wheat, hence the importance of breaking this bridge two weeks before planting.
There are wheat varieties with a gene, WSM2, that resist WSMV. But these aren't foolproof. They might lack resistance to other mite-spread diseases and can be temperature-sensitive. Varieties resistant to the wheat curl mite are also available. They don’t block the disease but hinder mite growth.
Genetic resistance is maximized when combined with volunteer wheat control. This combined approach helps curb WSMV spread and ensures a promising harvest. Harries stresses that controlling volunteer wheat is the most effective strategy since chemical methods don't work on the mites.
Get more information and other guidance on controlling volunteer wheat at kswheat.com/wheatrx.
Photo Credit: istock-zhaojiankang
Categories: Kansas, Crops, Wheat