Farmers can’t control environmental factors like weather in order to give their wheat crop a healthy boost, but they can help curb disease by controlling volunteer wheat. So far, the state’s wet summer has enabled volunteer wheat to take root and grow rapidly. While it may sound tempting to graze these leftovers, volunteer wheat can pose a major threat to the next wheat crop due to increased disease infections and pest infestations.
“About 60-70% of the management practices a wheat producer takes to maximize yield on their farm occurs before planting, including a soil test to help determine fertility needs, variety selection, determining planting date and rate, etc. Among these practices, controlling volunteer wheat is of utmost importance,” said Romulo Lollato, Wheat and Forages Extension Specialist at Kansas State University.
According to the K-State Department of Agronomy, volunteer wheat within a half-mile of a field that will be planted to wheat should be completely dead for at least two weeks prior to wheat planting. Doing so will help control wheat curl mites, Hessian fly and greenbugs this fall.
“In the past, farmers have always left volunteer wheat for grazing,” said Jason Ochs, a Hamilton County wheat farmer. “Years ago they could leave that volunteer wheat and it didn’t hurt anything. But in today’s environment we are just not able to do that anymore.”
One of the major risks associated with volunteer wheat is the wheat streak mosaic virus complex. These viruses can cause severe economic damage, and in most cases infection can be traced to a nearby field of volunteer wheat. The diseases are carried from volunteer wheat to newly planted wheat, and can cause stunting and yellow streaking on the leaves of the plant.
“Yield reductions may not be 100% in all cases, but very often yield maps show 60-70% yield reduction in areas affected by wheat streak mosaic as compared to the average yield for a wheat field,” said Lollato. “It will not only affect your wheat crop, but your neighbor’s as well. Thus, help protect the Kansas wheat crop: make sure any volunteer wheat in your field is dead at least 2 weeks prior to planting your wheat.”
Wheat streak mosaic virus is carried from volunteer to newly planted wheat by the wheat curl mite; tiny, white mites that are too small to be seen with the naked eye. These small, but heavy hitting, insects use the wind to carry them to new hosts, which can take them as far as a half mile away.
Hessian flies are also an issue found lurking in volunteer wheat. These insects survive over the summer on wheat stubble and cause significant damage in the eastern two-thirds of the state. Tillers in planted wheat may be stunted due to the antics of Hessian flies, and may ultimately lodge during harvesting. According to K-State Agronomy, a whole stand may be lost in heavy infestations.
Other pests can also reside in volunteer wheat. These pests can include Russian wheat aphids, Banks grass mites and chinch bugs. In addition, volunteer wheat and other weeds use up large amounts of soil moisture.
Destroying volunteer after the new wheat emerges is too late, according the K-State Agronomy. Tillage and herbicides are the two options available for volunteer control, but farmers need to start these methods early, in order to leave time for a second chance if control is not complete.
“The biggest thing is that we all have got to work together as farmers and change with the times,” said Ochs. “This is a different time than it was 15 or 20 years ago when we didn’t have to control volunteer wheat.”
For more information on controlling your volunteer wheat, head to agronomy.k-state.edu.