190 MAINE AGRICULTURAL EXPERIMENT STATION. I914. 



Banner variety were tested in 1910. These strains came from 

 widely separated provinces in Canada. The strains from 

 Alberta and Saskatchewan yielded much better than the strains 

 from Ontario and New Brunswick. 



Of the eleven varieties which have been tested for all four 

 years the Irish Victor gave the best average yield (63.7 bushels 

 per acre). The Imported Scotch, Lincoln and Prosperity aver- 

 aged to yield at nearly the same rate. The Senator, a horse- 

 mane oat, with very coarse straw and large plump grains, gave 

 the lowest average yield (49.3 bushels). 



A study of the variation constants (standard deviation and 

 coefficient of variation) for the four year period shows that the 

 Victor (a black oat) and the Imported Scotch were by far the 

 least variable of any of the varieties tested. This indicates that 

 these varieties are much less affected by seasonal differences 

 than the others. Further as shown in Table 7 the Imported 

 Scotch shows less variation between its four plots in 191 3 than 

 any of the other varieties. Consequently the present data indi- 

 cates that the yield of this variety is less affected by environ- 

 mental conditions than that of the other varieties tested. 



It is pointed out in this paper that the variation constants 

 measure a very important character of a variety. A variety 

 which will yield very highly under favorable conditions but 

 very poorly under unfavorable ones is not so desirable in the 

 long run as a variety which will yield moderately well under 

 any of the conditions that are likely to be met in any season. 

 Further the variation constants and the probable errors calcu- 

 lated with their aid give a very desirable measure of a series of 

 tests. 



The yield of straw and its variability in the four years is dis- 

 cussed. Also the relation between the amount of straw and the 

 amount of grain is shown in Table 11. The Lincoln, Banner, 

 and Irish Victor gave the largest average yield of straw. The 

 Imported Scotch, Kherson and Victor gave the smallest amounts 

 of straw. The Senator and the Regenerated Swedish Select 

 gave the largest proportion of straw to a given weight of grain, 



