by Nebraska State Horticultural Society

1919

by Nebraska Potato Improvement Association

1926

by Nebraska. State Board of Agriculture

1922

by Nebraska Potato Improvement Association

1928

by Nebraska. State Board of Agriculture

1922

by Nebraska State Horticultural Society

1918

by Nebraska State Horticultural Society

1916

by University of Nebraska (Lincoln campus). Agricultural Experiment Station

1925

by Nebraska. State Board of Agriculture

1924