SEED SHOULD BE GROWN FROM SUPERIOR VARIETIES AND STRAINS OF ALFALFA
The present tendency in alfalfa improvement is to establish narrow types or strains for special purposes and which are adapted to a particular set of conditions. It was at one time thought that an alfalfa variety with numerous types of plants would have a wider range of adaptability to diverse conditions and that inter- crossing among the different plants would maintain the vigor of the variety.
Carlson, John W., "Circular No. 97 - Growing Alfalfa-Seed" (1932). UAES Circulars. Paper 86.