Arrested Ears Feedback
Posted: September 18, 2012
Four individuals reported observing the roadside arrested ears syndrome in different areas of the state. That suggests that it’s not something unique about the limestone in Nittany Valley. It also confirms that we are not the only ones seeing the problem.
One person reported that his hybrid strip test that ends along a gravel driveway will often show a hybrid or two with the symptoms each year. This suggests that there could be some genetic effect to the problem.
I also got a response from the Center for Dirt and Gravel Roads here at Penn State. They shared a study done on gravel roadbeds in state forests where limestone was used for the road surface and contrasted that with the native aggregate surfaces. The limestone resulted in dramatic (2-4 x) increases in soil Ca and Mg within 10 meters of the roadside. This caused changes in the roadside vegetation as well. A student recently completed a thesis on this study and reviewed some of the literature on airborne dust pollution on roadsides. So there are significant impacts of roadways on soils.
Another observer reported that he saw symptoms along a paved, not dirt, roads. Allan, here in Centre County, confirmed to me this week that some of our issues have been next to paved roads as well. This may suggest that the issue is related to runoff and not dust alone.
I got a couple of comments about fungicides and herbicides and while they can cause some ear development problems, none of our fields have been treated with fungicides and we have not seen any relationship with herbicides and the symptoms.
So it seems like some materials blowing, washing or being pushed off of roadways could be associated with the problem and it may be mediated by plant genetics. It could be related to Ca, Mg, Na, Cl, or pH. Not sure we have solved the problem yet but I feel we know more than we did last week and that’s pretty good progress. Thanks to all who provided some feedback.
- Professor of Agronomy