Crop production principles and practices
Metcalfe, Darrel Seymour.
Elkins, Donald M.
Hughes, Harold De Mott.
New York Macmillan London Collier Macmillan
1980
Previous ed.: / by Harold D. Hughes, Darrel S. Metcalfe, Iver J. Johnson. 1972
Includes bibliographies and index
Field crops.