- 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
- Edgar John Udine, Edmund Lambert, Edward Mackay Chace, Emil George Boerner, F. L. Duley, Franklin Arthur Coffman, George Emil Gaus, Gerard Dikmans, Harold Robert Hochmuth, John Stuart Pinckney, Joseph Benjamin Shepherd, M. A. Yothers, Mark Hughlin Haller, Robert Hale Nelson, Roland McKee, Russell Rutherford Whitten, United States. Department of Agriculture, Victor Leo Stedronsky, W. A. Douglas, W. G. Bradley, William John Reid, William Solomon Porte, Carroll Clayton Cassil, Charles Scott Shaw, Dean Humboldt Rose, Earl Raymond Franklin, Harry August Schoth, Harry Bruce Walker, Latimer Ludwig Kelly, Paul B. Allen, Rhea Emerson Stitt, Thomas Laffin Baggette, Thompson Elwyn Woodward, William Alexander Noel, Arvid John Johnson, Marion Clawson, Paul Lewis Harding, Vinnie Arah Pease, Waldo Harold Kliever
· 1941