No. 570] 



ALFALFA BREEDING 



sufficiently constant to hold the place variation of this 

 character to the plus side of the equation for four out of 

 five determinations made, as is seen in the following 



Correlation. -f- 10 ± .10 + .23 ± .10 + .16 ± .10 -f- .46 ± .08 —.12 ±.10. 



These correlations, however, are low and seem to indicate 

 that the natural varietal traits were being overcome and 

 obscured by other variable factors. 



Contrary to expectation, the stand had little to do with 

 the percentage of leaves, as the following low and incon- 

 stant correlations show. 



TABLE VII 



On the other hand, the relation between height and 

 yield and percentage of leaves was constant and marked, 

 except in the last two cuttings. 



The sudden change from minus to plus in these correla- 

 tions should be noted. The average heights of the first 

 four cuttings were 32, 30, 28 and 27 inches, respectively. 

 The average height of the fifth and sixth, were 15 and 12 

 inches. This would suggest that at or below 15 inches the 

 mutual shading of the stems is not sufficient to cause an 

 appreciable shedding of the lower leaves. Up to this 

 point, moreover, growth usually takes place by an increase 



