Minnesota extention specialist in agronomy, entomology, plant pathology, and soils Agricultural Extension Service University of Minnesota2014-12-302014-12-301979https://hdl.handle.net/11299/16905079 pages; includes drawings. 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.en-USNewsletter or Bulletin