plants

This study suggests rogue prions can occur in corn, tomatos, and alfalfa Does this mean farmers will have to test all plants that die on their farms? I see border closings on alfalfa coming. http://www.wisconsinwatch.org/2013/09/27/prions-in-plants-new-concern-for-chronic-wasting-disease/

I heard you don't want to have red oak trees in the pens and I heard of one other tree you don't want to have. Does anyone know of any plants not to have in pens? Someone has told me walnut trees but I never heard that