ALFALFA 
THE RELATION OF TYPE TO HARDINESS. 
By Philo K. Blinn. 
For forty years alfalfa has been grown with marked success 
throughout the irrigated areas of Colorado. It has fitted our condi¬ 
tions so well that there has been little cause for failure aside from 
the lack of moisture. But it is a matter of common observation that 
there is a gradual loss of plants in the fields of ordinary alfalfa as 
they become older. In the very old fields, the stand of plants is almost 
invariably thin. This is usually ascribed to the overcrowding of plants. 
The thinning out has not usually seemed to decrease the yield of hay. 
The remaining plants seem to appropriate the extra space to good ad¬ 
vantage, the increased size and number of stems making the total 
yield of hay almost constant. Thus the thinning out has not been 
regarded as a very serious injury unless it has been unusually severe, 
in which case it is said to have “run out” or “winter-killed.” When 
it reaches this stage it is usually abandoned for hay production, plow¬ 
ed up and in time reseeded. 
In recent years the Colorado Experiment Station has been re¬ 
ceiving numerous complaints that alfalfa is not producing what 
it did in former years. These complaints are made in regard to both 
hay and seed production. Investigation seems to verify the truth of 
the claims. There are many local and specific causes for som/e of the 
complaints, such as, the injuries caused by grasshoppers, over-pastur¬ 
ing or injudicious irrigation. There is additional cause for a general 
complaint in regard to alfalfa production due to a lack of vigor and 
vitality in the strains commonly grown. These common types we 
might class as the southern or Spanish varieties. Originally the al¬ 
falfa that was planted in California and the other western states came 
from South America, and was in turn introduced into that country 
by the Spaniards during their early conquests. Most of our ordinary 
alfalfa can be traced to this origin. 
The Colorado Experiment Station has conducted alfalfa im¬ 
provement experiments since 1904 . One of the results of these ex¬ 
periments has been to show the lack of hardiness in the southern alfalfa 
types. Attention was called to the contrast in seed yields and the 
great difference in types of plants found in the same fields. From 
certain choice individual plants found at different points in the Ar¬ 
kansas Valley in southeastern Colorado, seed was selected and saved 
for the beginning of an experiment in systematic seed breeding. The 
most promising of these selections were sown in a nursery plat 
April I 5> I 9°5- I n this plat was also sown some ordinary commercial 
seed secured from a dealer in Rocky Ford, Colo., and some imported 
Turkestan alfalfa from Germany, furnished by Professor W. H. Olin. 
