266 Peach-Growing 



Course of development. 



The affected leaves first show minute dark spots. These 

 increase in size slightly, the diseased areas die and fall out, 

 thus producing the "shot-hole" effect. The affected areas 

 may run together more or less if they happen to occur near 

 one another. The affected leaves gradually turn yellow, 

 or otherwise cease to function and drop off. 



Cherry and plum trees are often so badly defoliated in this 

 way that it becomes a serious problem. The injury to peaches 

 in well-cared-for orchards is not likely to be noticeable. 



Methods of control of shot-hole. 



But very little experimental work has been done in the 

 control of these troubles. However, orchards that are 

 properly sprayed for brown-rot and scab are not likely to 

 suffer seriously from them. 



Bacterial leaf-spot, bacterial shot-hole, bacteriosis, black-spot 

 (Bacterium pruni) 



These are all common names for the same disease, the 

 terms being applied to different stages of the disease or to its 

 appearance in different places. As is suggested by the 

 names, the cause of the trouble is a bacterium. It is rather 

 widely distributed east of the Mississippi River and occurs 

 as far west as Kansas and Nebraska, but is more serious 

 in some of the peach districts of the South than elsewhere, 

 especially in neglected orchards. 



Course of development. 



This disease affects the leaves, twigs, and fruit, though it 

 is perhaps most noticeable on the leaves. When much 



