by University of Arkansas, Fayetteville. Agricultural Extension Service

1914

by University of Arkansas (Fayetteville campus)

1922

by University of Arkansas (Fayetteville campus) Agricultural Extension Service

1918

by University of California Agricultural Extension Service

1921

by Kansas State University. Engineering Experiment Station

1926

by University of Tennessee (Knoxville campus). Department of Agricultural Education

1921

by Kansas. State University of Agriculture and Applied Science, Manhattan. Division of College Extension

1928

by University of Massachusetts at Amherst. Cooperative Extension Service

1930