A STUDY OF FACTORS INFLUENCING THE YIELD OF POTATOES 1161 



this region is heavier and of lower natural fertility. Further evidence 

 of this condition is found in the figures showing a greater percentage of 

 unharvested yield due to blight rot, which is so common in these heavier 

 soils, at the higher elevations. 



The Green Mountain, or white-sprout, type of potato withstands less 

 heat than does the Rural, or blue-sprout, type. Where the growing- 

 season temperature is relatively cool, as in Franklin and Clinton Counties 

 and on Long Island, the white-sprout type is therefore more common. 

 In Steuben County, of 94 farms growing the white-sprout potatoes, 61 

 per cent were located above 1660 feet elevation and only 39 per cent were 

 located below this level. Of 239 farms growing the blue-sprout type, 

 50 per cent were above and 50 per cent were below 1660 feet elevation. 

 There is some tendency, therefore, to grow more of the white-sprout type 

 at the cooler altitudes. 



Influence of elevation in Monroe County 



The range of elevation in Monroe County is between 400 and slightly over 

 800 feet. Little opportunity is therefore afforded to study the influence 

 of this factor in this region. The figures in table 4, interpreted in the light 

 of average seed and fertilizer used, show that elevation has some tendency 

 to increase yield. 



TABLE 4. RELATION OF ELEVATION TO YIELD ON 296 MONROE COUNTY FARMS IN 1913 



Influence of elevation in Franklin and Clinton Counties 



A variation of over 1500 feet elevation in the farms in Franklin and 

 Clinton Counties affords excellent opportunity for the study of the influence 

 of elevation on yield. The summary given in table 5 shows a rather marked 



