by Arthur Vance Swarthout, Benton Early Rothgeb, Carl Joseph West, Emily Florence Alger Hoag Sawtelle, Frederick William Kressman, George Alfred Collier, Harry B. McClure, Harry Nelson Vinall, John Andrew Bexell, Robert Ellsworth Getty

1928

by 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