- Charles A. Fort, Charles Chase Hill, David Francis Costello, David Irving Blumenstock, Doys Andrew Shorb, Elmer R. Roth, Ethelbert Lee Langsford, Everett Elmer Wehr, Frank M. Eaton, Horace Preston Lanchester, Irvin Carl Feustel, Leander D. Howell, Lucy Maclay Alexander, Lyle Thomas Alexander, Mark Hughlin Haller, Milton Henry Fohrman, Robert Edgar Worthington, Roy Hyer Canfield, Stafford Coleman Happ, Thomas Randall Carson Wilson, United States. Bureau of Plant Industry, Vernon Webster Johnson, William Gustavus Wahlenberg, Bailey Sleeth, Ben Hur Thibodeaux, Gordon Rittenhouse, Horace Greeley Byers, John Stuart Pinckney, L. V. Wilcox, Nancy Griswold Clark, Nelson McKaig, Paul Lewis Harding, R. R. Graves, Raymond Price, Sidney Henderson, Smith Winford Greene, Edgar John Udine, Gilbert Colfax Dobson, Glen Edgington, Hiram Richard Reed, James Hayes Marshall
· 1940
- Alfred Leroy Baker, Benton Mehrling Stahl, Charles William Loomer, Claude Kedzie Shedd, Donald Eisenbrey Church, Edward Pendleton Carter, Elsa Orent-Keiles, Fenner Satterthwaite Stickney, Frank Custer Edminster, Harry Curtis Young, Hazel Marie Fletcher, Herbert Halden Walkden, James Robert Dawson, Joseph Bailey Edmond, Leo E. Holman, M. A. Yothers, Marshall Tracy Deonier, Matthew Drosdoff, Myron Francis Babb, Ralph Dickieson Jennings, Ralph Leroy Parshall, Robert Douglass McCulley, Roy Wesley Nixon, Tom Part Cassidy, W. P. Baird, United States. Department of Agriculture, Arnold M. Hansen, David Victor Kopland, Dwight Fletcher Barnes, Frank Waldemar Carlson, George Yankush Young, James E. Kraus, Maurice E. Dahmus, Vernon Webster Johnson, Walter S. Atkinson, William Henry Black, Arthur Clifton McIntyre, Mary Ellen Duensing, Perez Simmons, Roy Magruder
· 1950