96 THE POTATO 



4 inches of soil because it was warmer than the 3 or 4 

 inches lower down. 



Influence of Depth on Quality. — On a sandy loam, 

 under New York conditions, potatoes grown about 4 

 inches deep are generally of better quality than those 

 grown nearer the surface. In other places, those 

 grown at even greater depths have been observed to 

 be of better quality; thus, at North Dakota Station,' 

 potatoes 5 to 6 inches deep were better than those 3 or 

 4 inches deep in this respedt. 



Date of Planting. — As would be expedled, the 

 dates of planting potatoes vary widely, and the only 

 way to deal with the question is to give the common 

 dates for a certain locality. The reader is advised to 

 inquire of the growers in the locality the date con- 

 sidered best, and, as a general rule, it is wise to plant 

 early for the distri(5l. Canadian experimenters' report, 

 after four years' trial, that the end of May is the best 

 time, and that June 24 is usually found to be the latest 

 date for planting potatoes to produce satisfadlory re- 

 turns, although in 1900 a good crop was obtained from 

 a planting on July 7. In Wisconsin the middle to the 

 end of May, and in Maine late in May and early in June, 

 are considered best. At Cornell University, in 1901, 

 potatoes planted May 16 yielded 250 bushels per acre, 

 while those planted June 12 and 17 yielded 162 and 197 

 bushels respecflively. In Oklahoma^ potatoes planted 

 March 14 came up and matured as early as those 

 planted February 27. The early potato crop of Vir- 

 ginia is usually planted during February and March, 



' N. V. Report, 1901, p. 96. ' Can. Exp Farm Report, 1901, p. 119. 



' Okla Hul. 52, p. 9. 



