A STUDY OF FACTORS INFLUENCING THE YIELD OF POTATOES 1175 



TABLE 18. 



RELATION OF DEPTH OF PLOWING TO YIELD ON 360 STEUBEN COUNTY FARMS IN 

 1912 



for potatoes were inclined to plant more seed and to use a greater value of 

 manure and fertilizer. The difference in yield of nearly 24 bushels per 

 acre resulting from a difference of 4 inches in depth of plowing is evidently 

 due, in part at least, to the increase in depth of plowing. The coefficient 

 of correlation shown in figure 133 is 0.190 0.034, a value expressing 



Yield per acre, in bushels 



8 



2 5 26 64 73 78 52 38 9 10 2 1 360 

 r = 0.190 d= 0.034 



FlG. 133. CORRELATION OF DEPTH OF. PLOWING AND YIELD ON 360 STEUBEN COUNTY FARMS IN 



1912 



significant correlation. Most of the crop in this region is grown on soils 

 underlain at rather shallow depths with more or less impervious strata. 

 Deeper plowing under these conditions would tend to enlarge the area 

 adapted to maximum tuber development. 



Depth of plowing in Monroe County 



The soils of Monroe County may be considered intermediate in texture 

 between those of Long Island and those of Steuben County. As a rule, they 

 are deeper than those of the latter region. A study of table 19 shows no 



