112 



AGRICULTURE FOR BEGINNERS 



is caused by another fungus, which attacks the foliage of 

 the potato plant. When the blight seriously attacks a 

 crop, it generally destroys the crop completely. In the 

 year 1845 a potato famine extending over all the United 

 States and Europe was caused by this disease. 



FIG. 99. SPRAYING MACHINE 



Spraying is the remedy for this disease. Fig. 98 

 shows the effect of spraying upon the yield. In this case 

 the sprayed field yielded three hundred and twenty-four 

 bushels an acre, while the unsprayed yielded only one 

 hundred bushels to each acre. Fig. 97 shows the result 

 of three applications of the spraying mixture upon the 



