- A. J. Pieters, Archibald Dixon Shamel, Benjamin Ralph Stauber, Chalmers Jackson King, Charles Sidney Leete, Charles Walter Collins, F. M. Grant, Fred Earl Keating, Frederick John Pritchard, Frederick Wulling Herbert, George McMillan Darrow, George Wright Hoffman, Harry Eugene Burke, Harvey John MacAloney, Hazel Katherine Stiebeling, Herman Meserve Johnson, Mary E. Sweeny, Neil E. Stevens, Orville Edward May, Oscar Roland Mathews, Perley Spaulding, Robert Claude Wright, Thomas Moore Whiteman, United States. Department of Agriculture, Walter Cochran Davis, Carl Stone Pomeroy, Charlotte Chatfield, Clarence Elbert Clement, George Fordyce Waldo, Harold Frederick Loomis, Horace Terhune Herrick, James Warren Hubbard, John Raymond Hansbrough, John Valentine Schaffner, Louis Henry Burgwald, Ruth Leah Morgan, Verner Ivan Clark, William Solomon Porte, Frank Nelson Harmon
· 1931
- Arthur Vance Swarthout, Charles Sidney Leete, David Griffiths, David Segrid Olson, Elmer Lash, Ernst H. Wiecking, Frank Getz Ashbrook, Frank Heidtman Lathrop, Frederick Charles Lincoln, George Emil Heck, George Herbert Coons, H. F. Willard, Harold Coleman Hallock, John Chambers McDowell, Justus Watson Folsom, M. A. Yothers, R. W. Leukel, Ralph Henry Elsworth, Reginald D. Forbes, United States. Department of Agriculture, Walter Cochran Davis, Wiley Croom Smith, William Gustavus Wahlenberg, Charles M. Harris, Dewey Stewart, Donald Bruce, Fletcher Pearre Veitch, Floyd Frank Bondy, Ira Burton Lanphier, Karl Burchard Hanson, Theodore Lemuel Bissell, William Melvin Mohler, Finley George Larmer
· 1929
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No image available
No image available
No image available
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Benjamin Schwartz, Charlotte Chatfield, Chester Otis Reed, E. R. Van Leeuwen, E. W. Sheets, Eloise Blaine Cram, George McMonies Hunt, Glen Blaine Ramsey, James William Park, John Brown Cuno, John Harold Lister, Joseph Lyonel King, Karl S. Quisenberry, Liberty Hyde Bailey, Lorin Harvey Bailey, Marinus Westveld, Neil E. Stevens, Perry Eugene Howard, Robert Montgomery Gehl, Roland McKee, Sherlock Melvin Dietz, Theodore Bergen Manny, Vera Katherine Charles, Wilbur Magruder Hurst, William Orrin Robinson, Charles Ranger Enlow, Cortes Gilbert Randell, Georgian Adams, Jacob Allen Clark, James Keever Holloway, Lysle Douglas Leach, Marion Imes, Robert Henry Black, William Ensley Jackson, Willard Hull Wright· 1930