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BiTTEE-RoT. 



In Massachusetts, bitter-rot is of comparatively little im- 

 portance. In other parts of the United States, notably the 

 middle Atlantic and middle western States, it is in some years 

 the most destructive disease in the orchard. 



The causal fungus, Glomerella cingulata, produces a dry, bit- 

 ter rot of the apple flesh. The disease usually begins in July 

 or August as small, round spots, brown in color. These spots 

 soon become sunken and increase in size, usually exhibiting a 

 spries of raised concentric rings. (Fig. 6.) Minute black 

 fruiting bodies develop in the rotted area either in concentric 

 rings or scattered. These bodies eventually discharge small 

 masses of pink spores which disseminate the disease. In the 

 final stages of the disease the fruit becomes shriveled into a 

 hard, dry mummy. 



Brown-Rot. 



Brown-rot is important chiefly as it affects some early vari- 

 eties, such as Red Astrachan and Yellow Transparent. The 

 amount of loss which it causes is not large. It is caused by 

 the same fungus, Sclerotinia cinerea, which produces brown- 

 rot of peach, plum and cherry. The fungus usually gains en- 

 trance to the fruit through a wormhole or other injury. 



The disease starts as a small brown spot, which rapidly 

 spreads through the entire fruit as a soft rot. Often the rotted 

 fruit turns black, and the disease may be mistaken for black- 

 rot. It remains more or less smooth on the surface and does 

 not shrivel and wrinkle as in the case of black-rot. In warm, 

 moist weather small grey tufts of spore masses form on the 

 surface of the rotted area. 



Sooty-Blotch and FLY-StECK. 



The name, sooty-blotch and fly-speck, is indicative of the 

 appearance of this disease. (Fig. 7.) The causal fungus, Lepto- 

 thyrium pomi, is entirely superficial in its attack on the fruit, 

 and its effect is merely to form surface blemishes; however, the 

 disease must be considered of considerable importance because 

 of the greatly reduced market value of fruit disfigured by it. 



