APPLE DISEASES 119 



sometimes call the disease canker, but this name should be 

 avoided. 



Cause. 



Pink-rot is a fungous trouble, the pathogene of which is Ceph- 

 alothecium roseum. The organism was discovered in Austria 

 about 1836 and is now known all over the world. The fungus 

 lives commonly as a saprophyte on dead and decaying vegetable 

 matter. Its spores may be found floating in the air almost 

 anywhere. Consequently when a wounded or scabbed surface 

 of a ripe or nearly mature apple is exposed, these floating conidia 

 come to rest on such places, germinate, and their germtubes 

 enter the apple-flesh. Scab-lesions furnish the most common 

 point of entrance. The upturned skin at the edge and the 

 cracks at the center of such spots seem to be particularly 

 adapted to penetration by the pink-rot organism. The causal 

 fungus cannot enter through the unbroken skin. Sometimes 

 pears, quinces, grapes and plums are attacked in a manner simi- 

 lar to that of the apple. 



Control. 



The history of the disease shows that it was most troublesome 

 in the days when apples were piled after being picked. Under 

 such conditions the fungus found excellent conditions for growth 

 and worked great destruction. Where apples are still so handled, 

 the practice should be discontinued. Fruits that are free from 

 scab are freer from pink-rot than scabbed apples. It is almost 

 unnecessary to state, therefore, that thorough and timely spray- 

 ing or dusting for apple-scab should be given strict attention. 

 Cold storage keeps the fungus in check but does not kill it, as 

 shown by the fact that it grows vigorously when removed from 

 such storage to a warm room. However, it is recommended 

 that apples be stored in a dry, well-ventilated room where the 

 temperature is kept at 32 Fahr. Apples picked, barreled and 

 immediately stored show noticeably less pink-rot than those 

 which suffer some delay between harvest and storage. In 



