- Albert Watts Moore, Birely J. Landis, Charles Chase Hill, Charles Stewart Bisson, Edmund Ellsworth Vial, Edwin Richard Kalmbach, Frederick Lovejoy Wellman, Frederick Strauss, Harry Vaughn Harlan, Homer Charles McNamara, Homer LeRoy Shantz, Kenneth Thurman Williams, Lela Evangeline Booher, Loren LeRoy Davis, Paul Random Henson, Ralph Hoagland, Raymond Leslie Spangler, Rutillus Harrison Allen, Theodore Comstock Scheffer, Theodore Thomas Ayers, William John Reid, Camille Leon Lefebvre, Dalton Ray Hooton, Erling Hole, Eva Ruth Hartzler, George Gordon Snider, George Haymaker Vansell, Harvey Leroy Westover, Hubert William Lakin, Jenkin William Jones, John Stuart Pinckney, Louis Hyman Bean, Mary L. Martini, Neale F. Howard, R. L. Piemeisel, Ralph Melvin Lindgren, Robert Claude Wright, Dow Dewey Porter, Harland Stevens, Horace Greeley Byers, Howard Wilfred Johnson, Ronald Lester Mighell, Walter Brown Dye, Walter M. Peacock
· 1941
- Lela Evangeline Booher, Robert Van Rensselaer Reynolds, Arlo McGrillis Vance, Arnold Kent Balls, B. L. Wade, Clarence Francis Kelly, Earl W. McComas, Erastus Newton Bates, Frank Shirley Chamberlin, George Haymaker Vansell, Hamilton Paul Traub, Hazel Katherine Stiebeling, Herbert Halden Walkden, James William Park, John Paul Miller, Ralph Corbin Hall, Robert Hibbs Peebles, Roger Ulysses Swingle, Russell Rutherford Whitten, W. A. Douglas, Walter Jay Hall, William Doyle Reed, William Henry Black, United States. Department of Agriculture, Albert Halsey Pierson, Archie Hugh Madden, Burwell Britt Powell, Eva R. Hartzler, Jesse Wilburn Ingram, John Paul Vinzant, Malcolm Ernest Smith, Marian William Hazen, Sadye Frances Adelson, T. Ralph Robinson, Verner Ivan Clark, Elizabeth Margaretta Hewston, Ennis C. Blake, Harold Edwin Stevens, James Edwin Comfort
· 1942
- Albert Watts Moore, Carl F. Dunker, Charles D. Converse, Claron Owens Hesse, Elmer Snyder, Everett Eugene Lund, Frank Custer Edminster, Franklin Elmer Allison, Franklin Jacob Crider, George Haymaker Vansell, Guy Weston Bohn, H. O. Hetzer, Harry Edward Goresline, Henry Hamilton Bennett, Herbert Spencer, Jesse Edward Harmond, Leslie Rushton Hawthorn, Myron Sallee Anderson, Oscar Roland Mathews, Ralph William Marquis, United States. Department of Agriculture, Elbert Hann Reid, Forrest G. Bell, Frank Nelson Harmon, Kirby M. Hayes, Leonard M. Klein, Lester Alan Thompson, Max Raymond Osburn, Sidney Fay Blake, Thomas Wallace Whitaker, Alfred W. Otte, Arnon Lewis Mehring, Bert D. Robinson, Paul A. Norman
· 1951