124 MAINE AGRICULTURAL EXPERIMENT STATION, I916. 



The most marked variation was in the Days to Maturity. 

 For individual plots this ranged from 123 to 112 with an aver- 

 age of 116. This was 19 days more than in 1914 and 15 days 

 more than in 1913. The reason for this probably lies in the 

 nature of the season and also in the fact that the plots were 

 sown very much earlier than in former years. Apparently the 

 grain ripened at about the same time of the year as usual 

 regardless of the fact that it had been planted 10 to 12 davs 

 earlier. 



More detailed discussion of these pure lines will be under- 

 taken in later paragraphs. 



VARIATION IN THE YIELD OE THE I915 PLOTS. 



Surface and Barber (hoc. cit.) have pointed out that other 

 things being equal the variety which shows the least tendency 

 to vary under different environmental conditions is the best 

 variety. Thus what is most desired in a variety is one which 

 will give a good substantial yield under all kinds of soil and 

 climatic conditions to which it is likely to be subject. Only in 

 19 1 5 are there sufficient data for determining the variation be- 

 tween different plots. For this purpose it is desirable to use 

 the observed yields instead of the corrected. In the case of the 

 corrected yields other factors enter which, on the whole, tend 

 to lower the variability. The variation in the observed yield 

 shows the actual amount of difference due to differences in soil 

 and other environmental conditions. 



Table 6. 



Constants of Variation in Yield for the Four ip 15 Plots of 

 Each Pure Line. Observed Yields. 



Variety. 



Mean. 



Standard 

 deviation 



Coefficient 



of 

 variation. 





77.47 ± .91 

 76. 94 ±1 30 

 77. 94 ±1.50 

 79, 67 ±1.58 

 82. 77 ±1.65 

 78.83 ±2.27 

 73. 99 ±2. 19 

 82.19 ±2.44 

 79. 69 ±2. 54 

 80.15 ±2.66 

 81.31 ±2.78 

 77.73 ±3.26 



2.73± .65 

 3.86 ± .92 

 4.47±1.06 

 4.70 ±1.12 

 4.90±1.16 

 6.76±1.61 

 6.51 ±1 .55 

 7.24±1.72 

 7. 56 ±1.80 

 7.92±1.88 

 8.27±1.97 

 9.69±2.31 



3 . 52 ± .84 



Maine 307 



5 02 ±1 20 



Maine 230 



5.73 ±1 37 



Maine 357 



Maine 340 



5.90±1.41 

 5.92±1.41 



Maine 337 



8.58 ±2.06 



Maine 336 



8.79±2 11 





8.81 ±2.11 



Maine 346 



9.49 ±2.28 





9.88±2.16 



Maine 281 



10. 17 ±2.45 



Maine 286 



12.47 ±3.01 









79.06 



6:22 



7.86 







