Songer, J. GlennMerkal, RichardHall, Ralph F.Powell, Thomas W.Van Houweling, C. Donald2019-09-182019-09-181984-12https://hdl.handle.net/11299/2074481 online resource (PDF, 4 pages)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.enReport