Volunteer corn is prevalent in continuous corn rotations, where it’s harder to detect. Since most stacked corn hybrids are resistant to both glyphosate and glufosinate, there’s no practical way to eliminate volunteers, says Christian Krupke, Purdue University Extension entomologist.

These corn plants may produce ears and kernels, so growers won’t necessarily see a yield drop because of volunteer competition. The bigger question is whether these volunteer corn plants, which may also express variable levels of Bt toxin, allow more rootworms to survive and build up tolerance, Krupke says.

In another twist on the problem of herbicide-resistant volunteers: “In Minnesota, South Dakota and North Dakota, we also get questions about the reverse scenario – volunteer soybean in corn,” says University of Minnesota Extension weed scientist Jeff Gunsolus. Volunteer soybeans could present “another potential crop rotation bridge,” Gunsolus says, “but this time for soybean cyst nematode (SCN).” However, there hasn’t been any research on the impact of volunteer soybeans on SCN numbers or corn yields, he says.

For more on managing volunteer corn in soybeans go to: http://bit.ly/xL3dQ1.

For managing volunteer soybeans in corn, go to: http://bit.ly/xy3pZi