SHOT-HOLE FUNGUS 



269 



the upper surface of the leaves, which become dry and 

 brittle, and eventually drop out, giving to the leaf the 

 appearance of having been riddled with small shot. Tiny 

 perithecia are produced on the diseased portions. It has 

 been suggested that the present fungus is a stage of 

 Leptosphaeria pomona, Sacc. 





Fig. 69. Phyllosticta prunicola. i, apple leaves show- 

 ing the holes formed by the falling away of portions of the 

 tissue killed by the fungus ; 2, section through a peri- 

 thecium imbedded in the substance of the leaf, x 18 ; 3, 

 spores, x 300. 



PREVENTIVE MEANS. Not very destructive, unless 

 especially numerous on the leaves, when spraying with 

 dilute Bordeaux mixture is recommended. 



Superficially resembles the 'shot-hole fungus' Cerco- 

 spora tircumscissa, but the fruit is very different. 



