Pomaceous Fruits 



59 



distributed, as to the localities in which they produce serious 

 injury, that in the northern apple-growing regions of the 

 eastern United States orchardists spray chiefly to control 

 apple scab; in southern apple-growing regions, it may be 

 necessary to control apple scab, apple blotch, and ])itter-rot; 

 and in other regions to control scab and blotch. The general 

 climatic relationship of these fungi in the eastern United 

 States may be illustrated roughly by their behavior in 



Fig. 29. 



Sprayed apple trees from the same orchard as tho.se 

 shown in Fig. 28. 



Illinois. Apple scab is a serious disease in all parts of the 

 state; apple blotch is a serious disease as far as 40° north 

 latitude; and, ordinarily, bitter-rot does not cause serious 

 damage north of 39° latitude. It is thus necessary, in the 

 northern part of the state, to spray for apple scab only; 

 toward the southern part, it is necessary to spray for apple 

 scab and apple blotch; and still farther south, to spray to 

 control apple scab, apple blotch, and bitter-rot. 



