Diseases of Plum, Peach and Cherry. 235 



The fungus lives over the winter by means of perennial mycelium 

 In the unripened fruits which remain hanging on the tree or lying on 

 the ground. Fresh spores are produced by this mycelium during the 

 spring and summer which infect the blossoms, and later, the fruit. 

 Conidia are produced in great numbers on rotted parts of the plant very 

 soon after infection, and these also spread the disease. Rotted blos- 

 soms, falling and lodging against some other portion of the plant, in- 

 fect that portion with remarkable rapidity. 



Spores easily break thru healthy epidermis, altho punctures are 

 somewhat more favorable to infection. 



TREATMENT. 



The destruction of all mummies is a universal recommendation. 

 In a small orchard hogs or chickens might help by eating fallen fruit 

 before it rots. Raking up mummies can not be done unless previous 

 clean cultivation has been practiced. It is suggested that as easy a 

 way as any to get rid of the mummies would be to run a furrow down 

 the center of a row, rake the mummies in from each side, and bury 

 them. Because of the continuous production of summer spores and the 

 rapidity with which the disease progresses, control by spraying is dif- 

 ficult. The spraying recommended against leaf-curl and black spot is 

 also recommended for brown rot, and later sprayings are also recom- 

 mended; spraying near the ripening of the fruit must be with copper 

 acetate or ammoniacal carbonate of copper. The blighting of the blos- 

 soms might be prevented by spraying while the petals are falling. 



PLUM POCKET (Exoascus pruni). 



This disease shows itself in hypertrophied, bladdery plums without 

 any seeds. Infection takes place during or immediately after blos- 

 soming. The fungus lives thru the winter in the twigs, and spreads 

 by means of spores produced at the surface of the plum-pocket at ma- 

 turity, which comes at about the middle of the summer. 



TREATMENT. 



Prune off affected branches, and destroy them before the summer 

 spores mature. 



