Pomaceous Fruits 55 



mature apples. It is duo to gases given off from apples and 

 ma}" be avoided l)y aeration. 



Minor diseases. 



European canker ■'- {Nedrin galligena Bros.). — The Euro- 

 pean canker was not recorded upon the apple in America 

 prior to 1899, when Paddock mentioned its presence in Nova 

 Scotia and New York. Later it was noted in New Hampshire 

 and Ohio and is now known to be widely distril)uted from 

 the Atlantic to the Pacific. It constitutes a serious disease 

 in Europe and may become of importance here. The canker 

 enlarges year after 5^ear, but more slowly than black-rot 

 canker, and displays, when fruiting, numerous minute, deep 

 red perithecia which serve to distinguish it from other 

 cankers. 



Brown-rot ^° {Sclerotinia ciiierea, Monilia). — One of the 

 most serious apple rots in Europe, this disease fortunately is 

 not as yet destructive in America, though Sclerotinia cinerea 

 is occasionally met with as one of the minor causes of apple 

 losses. It has been observed in several states, notably New 

 York, Missouri, Nebraska, the Virginias, North Carolina, 

 Illinois, Minnesota, Arkansas, and New Mexico frequently 

 enough to call for printed mention. Brown-rot produces 

 complete decay of the affected apples, which turn brown, or 

 later black, become soft and wrinkled, and soon show pustules 

 of bushy mycelium breaking through rifts and fissures in the 

 skin over the diseased tissue. The diseased fruits may 

 mummify upon the tree or more frequently fall to the ground 

 and there shrivel to dry, hard, wrinkled masses, in which the 

 rot fungus winters. 



.Sooty-blotch'*^- {Glcendes pomigena (Schw.) Colby). — 

 Irregular, soot}", black blotches, especially conspicuous on 

 the lighter colored varieties of apples, are frequently seen 

 upon unsprayed fruit. The individual blotches measure 

 from 0.5-2 cm. across and are often so abundant that they 

 coalesce, giving the fruit a dirty appearance. The fungus 

 attacks the fruit late in the season, and is strictly superficial. 



