Agro-Climatological Investigations— Bensin 215 



seeds and plants from other regions with analogous climatic 

 environment. By ecological tests and study of the best adapted 

 varieties we are trying to establish standard varieties for the 

 region. These varieties have definite ecological and morpho- 

 logical features and are described by the ecologists as ecotypes 

 (Turreson 1922), agrotypes (McGregor 1927) or as regional 

 agrotypes— chorotypes (Bensin 1928). Character and behavior 

 of these chorotypes is the subject of careful experimental in- 



Table 6.— Number of degree days for maturity of grain crops in 1949 and 1950, 



College, Alaska 



! 949 1950 



Kind and variety Days to 



of grain crops maturity 



Wheat average 99 



Siberian No. 1 95 



Barley average 76 



Olli 73 



Oats average 85 



Table 7.— Solar radiation units per one pound of grain in 1949, College, Alaska, 



Hillside Field 



Total solar Yield 



Days to radiation bushels Gmcl/cm2 



Kind and variety maturity gmcl/cm2 per A. per 1 lb. 



Wheat average 99 39.822 40.4 16.4 



Siberian No. 1 95 39,573 37.0 17.8 



Barley average 76 32,539 47a 14.3 



olli 73 3M5 54-7 ii- 8 



Oats average 85 35-937 101.1 11.2 



vestigations and analyses. Climatic relations comprising pheno- 

 logical observations and the study of responses to the environ- 

 ment and to the seasonal variability during wet and dry seasons 

 is the first step. The best adapted chorotypes indicate a consider- 

 able stability manifested by the length of the phenological 

 phases and production of grain, while less well adapted varieties 

 indicate great fluctuations in growth and production. 



A summary of the data for this ecological analysis of the 

 acclimatization of grain chorotypes for the grain varieties grown 

 on the fields of the Alaska Agricultural Experiment Station in 

 1949 and 1950 are shown on Tables 6 and 7. The data show 



