CHAPTER XII 

 PLUM DISEASES 



THE plum furnishes food and habitation for several parasitic 

 fungi and bacteria. It is also affected with other ills caused 

 by frost and other factors not generally understood. Many 

 of these diseases are native in their origin, so that often 

 European plums are highly susceptible to important diseases 

 in America. 



BROWN-ROT 



Caused by Sclerotinia cinerea (Bon.) Schrot. 



No disease gives the commercial plum-grower so much trouble 

 as brown-rot. It occurs more or less every year, affects the 

 ripe or ripening fruit, and destroys it absolutely (Fig. 99). It 

 is equally annoying and destructive in small home gardens, 

 rotting the fruit just at the time when it is ready for use. 



It is said that thin-skinned varieties are more resistant to 

 brown-rot than others. It is also said that the Triflora, Amer- 

 icana and Japanese groups are more injured than plums in other 

 groups. The Burbank, Abundance and Satsuma are said to be 

 most susceptible, while several varieties are listed as resistant. 

 Among the latter may be noted : Hansom, Clinton, Forest 

 Rose, Indiana, Miner, Nebraska, Prairie Flower and others. 

 It is to be noted that most of the list of so-called resistant 

 plums are varieties of minor importance ; at least they are not 

 leading American plums. And it is doubtful whether the Bur- 



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