4 
Colorado Experiment Station 
and dependable water rights. It is located in one of the largest 
alfalfa growing districts in the state. At one time the Arkansas 
Valley was a very important alfalfa seed producing region. The 
experiments at Rocky Ford have been supplemented by co-operative 
tests with alfalfa seed growers in different parts of the state. Mucli 
work has been done in collaboration with the Office of Forage Crop, 
Investigation, Bureau of Plant Industry, Washington, D. C. The 
field observations have covered Colorado and a portion of the alfalfa 
seed producing sections of Utah and Idaho. The Office of Forage | 
Crop Investigation has furnished several lots of alfalfa seed varie- 
ties from different parts of the world which have been used in the 
tests and experiments. 
In the preliminary canvass of the investigation, theories and be- 
liefs were advanced by different growers and others in an attempt 
to explain the causes for success or failure of alfalfa to set seed. 
The concensus of opinion seems to be that the care of the crop, 
together with the ability of the grower to judge of the prevailing 
conditions and their effects upon the seed production are the most 
. important factors. 
A careful comparison of the results secured under actual field 
conditions seemed to be the most plausible method of attacking the 
problem. Accordingly, tests have been made and observations 
A later alfalfa nursery test of different types and varieties. Notice the large stooling row 
in the center, a typical hardy strain. The winter killed rows at the left and one on the 
right of the hardy strain came from Italian strains of seed, all of which are non-hardy. 
