13 



Experiments continued for ten years at the New York 

 (Geneva) Experiment Station have shown that spraying 

 increased the average annual yield of potatoes 97 bushels to 

 the acre. 



Harvesting the Early Crop. 



On account of the high price which often prevails for a short 

 time the early potato crop should be harvested and sold without 

 waiting for the tops to become dry. When the early potatoes 

 are of marketable size, and the price is high, it is usually best 

 to dig them at once, even though the weight of the potatoes is 

 no more than the weight of the vines. The increase in the 

 rate of yield is, however, often very rapid after the middle of 

 July, as is shown by the following results of experiments made 

 at the Rhode Island Agricultural Experiment Station : — 



July 11, first digging, 162 bushels to the acre. 



July 31, second digging, 338 bushels to the acre; daily gain, 8 bushels to 



the acre. 

 August 5, third digging, 371 bushels to the acre; daily gain, 6 bushels to 



the acre. 

 August 12, fourth and last digging, 393 bushels to the acre; daily gain, 



3 bushels to the acre. 



Harvesting the Main Potato Crop. 



As long as the vines in a potato field remain green and 

 healthy it is certain that the potatoes are growing; hence it is 

 the practice of many not to dig the main crop until the tops 

 are dry and dead, showing that the crop is ripe. This is the 

 ideal stage for harvesting because the skin of the tubers is 

 generally set, and they can then be handled without material 

 injury. 



If only a few acres of potatoes are grown it is best to dig 

 them by hand or to use one of the many plow types of diggers. 

 These are sometimes of great assistance, but usually require 

 more or less hand work to uncover some of the potatoes that 

 have been buried by the plow. If a grower has a considerable 

 acreage of potatoes it is usually profitable to use a digger of the 

 elevator type, which requires four horses to properly operate it. 



After digging, it is best to gather the potatoes as soon as 



