IRRIGATION OF FIELD CROPS. 



237 



ground is dry, irrigate some time before beginning to 

 set. If kept too wet, a large amount of tops and few 

 potatoes will be produced. 



Never flood the potato field nor allow the water to 

 reach the crown or stem of the plants. Always bear 

 in mind that it is the roots and not the tubers that are 

 to be watered. By the time the plants are four or five 

 inches high the roots are several times that long and no 





FIG. 61 — IRRIGATING A CROP OF POTATOES. 



more deep cultivation should be given them. Use 

 some form of cultivator that will keep about two inches 

 of the surface thoroughly pulverized. As said before, 

 it is advisable on sandy loam as soon as planting is 

 done to harrow with the row, using bull-tongues set to 

 run as deep as possible next to the row, the outside 

 ones being set shallow. As the potatoes begin to grow 

 reverse the shovels, running the outside deep and the 

 inside ones shallow, so as not to disturb the roots. The 



