62 



FUXGl AXD FUXGICIDES 



The mycelium of the fungus also winters over in the 

 tips of the young branches. 



Treatment. — A yigorous pruning of all affected 

 branches some distance from the tips, in order to remove 

 the mycelium in the tissues, seems to be the most prac- 

 ticable remedial measure. The joockets should, of 

 course, be removed before maturing, and the safest way 

 will be to burn all the material so cut off. 



Literature. — The best article upon this subject so 

 far, i^ublished in America, occurs in the United States 

 Department of Agriculture Report for 1888 (pp. 

 366-369). 



The Plum Fruit=scab 



Cladosporium carpophilum 



In Iowa and some other localities a comparatively 

 little known disease has recently been noticed on native 



a he 



FIG. 32. PLUM DISEASES. 

 a, b. Fruit scab ; c, f I'uit spot. 



plums. It appears when the fruit is ripening, in the 

 shape of minute round specks, of a paler or grayer color 

 than the surrounding skin. These usually enlarge as 

 the fruit ripens, finally attaining a diameter of a quarter, 

 or even half an inch. Several spots sometimes run 

 together to form a blotch. The mycelium of the fungus 



