HARVESTING 



191 



begin when the plants are six or eight inches high and should be 

 repeated at intervals of about two weeks until the crop is nearly 

 ripe. In badly infected regions, from five to seven applications 

 are made. This treatment also holds the flea beetle in check, for 

 Bordeaux mixture acts as a repellent to this insect. If Paris green 

 or arsenate of lead is added to the mixture, it will dispose of the 

 Colorado potato beetle. Thus, one line of treatment will hold 

 the four enemies in check. The spray should be applied to the 



Fig. 118. — Potato digger in operation. 



under as well as to the upper surface of the leaves in order to be 

 most effective. Special spraying outfits are equipped for this 

 purpose, and are capable of spraying from three to six rows at a 

 time (Fig. 117). 



Harvesting. — Potatoes are harvested by digging with spading 

 forks or potato hooks, or by means of a digger drawn by two, 

 three, or four horses. Sometimes an ordinary plow is used, but 

 it cuts many of the potatoes and bruises others, and is withal 

 unsatisfactory as a potato harvester. A modern type of potato 



