Hertz, Lenard B.Johnson, Herbert G.Lofgren, John A.2014-12-302014-12-301979https://hdl.handle.net/11299/16903120 pages; includes formulations and photographs. 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