Alfalfa in Kansas. 187 



tensively where an ice sheet forms over the fields. On the other hand, a 

 very severe winter, in the sense that there is a long period of extremely 

 low temperature, may result in little winterkilling of alfalfa, if the fall is 

 dry and if the ground is continuously under a deep cover of snow. It is 

 therefore plain that to be absolutely winter-hardy under all kinds of 

 winter conditions, alfalfa will have to have quite a combination of char- 

 acteristics. 



Thus far, the Grimm alfalfa, certain Turkestan strains, and a strain 

 of common alfalfa found growing near the village of Baltic, S. Dak., by 

 Professor Wheeler of the Agricultural College of that state, and called 

 Baltic alfalfa, all stand preeminent in respect to resistance to winter- 

 killing. Now Blinn, of the Colorado experiment station, has found that, 

 in the case of the winter-hardy types of alfalfa, the plants stool earlier 

 in life than the nonhardy forms, and stool more extensively, forming 

 extensive underground stems or root stocks, loaded with buds. These 

 root stocks, being underneath the soil, are thus protected by the soil cover- 

 ing from extreme exposures. With this extensively stooling crown, and 

 this mass of underground buds, Grimm alfalfa, for example, is enabled 

 to go through winters that kill alfalfas of our common Kansas type, 

 with their upright crowns and without protected buds. Furthermore, 

 there is a tendency among the hardier types of alfalfa to have a 

 branched root system instead of a single tap root. The Baltic strain of 

 alfalfa shows this characteristic in a high degree. It is also true that, 

 while drouth-resistant alfalfa strains may not be cold-resistant, the 

 winter-hardy types are, generally speaking, drouth-resistant. The un- 

 derground stems, bearing buds, and the branched root system, charac- 

 teristic of the winter-hardy alfalfas Grimm, Baltic, and certain alfalfas 

 from Turkestan are also characteristics which help the plants in ques- 

 tion to live over dry seasons. 



Finally, there is a difference among the alfalfa plants of almost any 

 hardy strain with respect to the susceptibility of the foliage to frost in- 

 jury. Side by side, plants of the same so-called "variety" will show the 

 greatest differences in this regard. Blinn, of the Colorado Experiment 

 Station, thinks that the darker green plants are less susceptible to frost 

 injury than are those with light-green leaves. We may then sum up the 

 steps thus far achieved in the work of breeding for winter-hardiness in 

 alfalfa as follows: 

 A. The introduction of hardy foundation stocks. Four important 



foundation stocks lie at the basis of breeding for cold-resistance 



in America, viz.: 



1. The Grimm importation in 1858 of a strain of the "Old Ger- 



man Franconian" alfalfa from Baden, Germany. 



2. Various Turkestan importations, and 



3. The introduction of Medicago falcata, or Sickle alfalfa, by 



Prof. N. E. Hansen, of the South Dakota College of 'Agri- 

 culture. 



4. The discovery, near the village of Baltic, S. Dak., of a hardy 



strain of common alfalfa by Prof. W. A. Wheeler, of the 

 South Dakota Agricultural College, which has been named 

 "Baltic alfalfa." 



