THE APPLE 



The apple-scab fungus usually precedes the pink rot, growing 

 beneath the skin, and as it matures, rupturing the skin and leav- 

 ing the edges somewhat upturned. It is near the upturned edge 

 that the pink fungus so often makes its beginning, forming a 

 ring of mold. The entire scab spot, however, is usually covered 

 with a white mold, which gradually changes to a pink or a rose 

 color as it is dusted over with the pale rose-colored spores. 



The first change in the appearance of the apples is that the 

 skin around the spots turns brown. This brown area gradually 



extends in all direc- 

 tions, the various spots 

 merging with one an- 

 other until a large part 

 or the entire surface of 

 the apple is covered. 

 As the spots increase 

 in size they also sink. 

 The sinking may be 

 due not only to the 

 dissolving of the solid 

 parts of the apple by 

 the fungus but also to 

 evaporation of water 

 through the spots. 

 The flesh beneath the 

 sunken spots is brown 

 like the skin above it 

 and is bitter to the taste. 

 Is the pink fungus a parasite ? In order to determine the method 

 of attack of this fungus, apples were inoculated with a pure culture 

 of the spores. These spores were placed on the scab spots of apples 

 which were free from the pink fungus, and also on sound apples. 

 Other fruits free from the fungus spores were kept as checks. The 

 apples having scab wounds were easily inoculated, but the sound 

 fruit was not affected. Apples which were suspected as being already 

 affected by the fungus were thoroughly disinfected and subjected to 

 the same tests with the same results. The fungus developed in the 

 tissues of the apple only where a wound had previously been made. 



Fig. 103. Pink rot following scab. (University 

 of Maine) 



