APPLE DISEASES 143 



reasonable to assume, however, that such is the case, judging 

 from the habits of the fungus on stone-fruits. 



Control. 



Careful remedial measures have not been determined for 

 American conditions. The suggestion is made on good authority 

 that spraying for apple-scab will help to control the apple 

 brown-rot. Store the fruits in a dry, well-ventilated, and clean 

 house at the customary low temperatures. 



REFERENCES 



Heald, F. D. The black-rot of apples due to Sclerotinia fructigena. 



Nebraska Agr. Exp. Sta. Kept. 19 : 82-9.1. 1906. 

 Clinton, G. P. Apple rots in Illinois. Brown rot. Illinois Agr. Exp. 



Sta. Bui. 69 : 190. 1902. 



EUROPEAN BROWN-ROT 



Caused by Sclerotinia fructigena (Pers.) Schrot. 



This disease probably does not occur in America, but is 

 discussed in order that a comparison of brown-rot of pome- 

 fruits in Europe and America may be made. 



European brown-rot of apple affects the fruits in a manner 

 similar to the American brown-rot (see Fig. 37). But Euro- 

 pean brown-rot also affects the flowers, shoots and foliage. 

 Diseased flowers are blighted. The woody parts, twigs a ad 

 limbs, are cankered (Fig. 38). The formation of a European 

 brown-rot canker on apple ordinarily proceeds as follows: 

 a hanging mummy presses against a fruit-spur and the two 

 adhere firmly ; the pathogene, Sclerotinia fructigena, then grows 

 from the apple-mummy to the branch. An affected branch 

 may be girdled and under conditions of high relative humidity 

 grayish tufts conidial structures of the pathogene develop 

 on the surface of the canker. Another method by which the 

 canker may originate is by the passage of the pathogene from 

 an affected blossom through the fruit-spur into the twig. 



