As wheat growers once again prepare to plant wheat, a Kansas State University entomologist emphasizes the importance of controlling volunteer wheat.
"Volunteer wheat is an unintended consequence of producing wheat," says Jeff Whitworth, a crop pest specialist with K-State Research and Extension. "We cannot avoid it, but we can manage it so that it will not help nurture many of our common wheat problems."
Volunteer wheat can act as a nursery for most traditional pests, including Hessian flies, Russian wheat aphids, wheat curl mites, bird cherry oat aphids and greenbugs, Whitworth says. Some of those pests can vector a virus that causes barley yellow dwarf, which also uses volunteer wheat as a host reservoir. Even chinch bugs benefit from the uncontrolled volunteer plants.
Controlling volunteer wheat is not easy, he said, especially since a new batch may germinate with each new shower.
"The general rule, however, is to make sure all volunteer patches are dead at least two weeks prior to planting," Whitworth says. "That way, any pests using the volunteer as a host will have to leave in search of a live host. If those pests are not successful in finding a new host, they will perish before your planted wheat becomes available."
Controlling volunteer is especially important this year because, due to an April freeze, Kansas producers had considerable acreage abandoned or lodged prior to harvest, he says. These fields have provided more suitable habitats for the pests to oversummer. Last spring, the state also had greater than usual densities of bird cherry oat aphids in a larger statewide distribution, which means the potential problems these pests cause are up, as well.
"This is a good time to become neighborly," Whitworth says. "Controlling your volunteer wheat is imperative, but to really protect your fields, your neighbors need to destroy theirs, also."
Hessian flies have wings, as do the aphids. All of the pests are small and light, too, so wind can carry them considerable distances, the entomologist says. Neighbor cooperation is important for at least 1/2 mile around all planted wheat fields.
"Also take care of your volunteer so that you are not responsible for infesting or infecting all of your neighbor's fields," Whitworth adds. "It doesn't make for a good relationship if you are identified as the grower responsible for the Hessian fly or barley yellow dwarf outbreak."