1244 EARLE V. HARDENBURG 



concerned in the whole survey, approximately 1100 practiced one of the 

 four types of cultivation listed in this table. Each of the remainder prac- 

 ticed one of the other possible five types of deep, medium, and shallow 

 early- and late-season cultivation. Cn the basis of weighted averages, the 

 best average yields were obtained from deep cultivation early in the season 

 and shallow cultivation late. 



RIDGE AS COMPARED WITH LEVEL CULTURE 



The system of potato culture in vogue almost universally thruout the 

 New England and Middle Atlantic States has been that of varying degrees 

 of ridging or hilling. An extreme ridging, comparable to that followed in 

 Aroostook County, Maine, is practiced in Franklin and Clinton Counties. 

 In only a few limited areas, notably the Long Island potato areas, is any- 

 thing approaching level cultivation common in these sections of the 

 United States. Regardless of the fact that several station experiments 

 have shown superior merit in point of yield from level culture, ridge culture 

 is by far the commoner. The more obvious advantages of ridge culture 

 consist in (1) greater ease in digging, (2) more efficient weed control by 

 covering rather than by removing and disturbing the root system close to 

 the row, (3) more friable soil for tuber development, (4) protection of tubers 

 from the spores of the late-blight fungus (Phytophthom infestans), and (5) 

 greater surface evaporation of moisture, a factor of special value on heavy 

 soils in regions of possible excess, or poorly distributed, growing-season 

 rainfall. 



Geismar (1905) compared hill and level culture on both fall- and spring- 

 planted potatoes. His yields favored level culture for both the fall- and 

 the spring-planted crops by 5 and 7 per cent increases, respectively. Geis- 

 mar very mistakenly added these increases and credited the total to the 

 advantage of level culture. This was a blight year at the Michigan 

 station, and, altho Geismar stated that the damage from the disease was 

 confined to the tops, it is possible that some protection from ridging was 

 furnished the ridged plots, and that in a dry year the advantage in level 

 culture would have been even greater. Stone (1905), at the Cornell 

 station, compared various frequencies of hilled and level culture for five 

 years on medium light soil. In each of these years, the yields were best 

 under level culture, the differences ranging from 1 to 37 bushels per acre, 

 the average favoring level culture by 14 bushels. Stone did not explain 

 why the smallest differences in yield occurred in the two driest years, when 

 the greatest advantage from level culture might have been expected. 

 During three of these five years, he compared continuous level culture up 

 to nine cultivations, with laying by and ridging the crop after from three 

 to five cultivations. In these tests, the continuous level culture gave an 

 average advantage of 54 bushels per acre. Shepperd and Churchill 

 (1911), altho reporting no data, stated that level culture has given far better 



