DISEASES 227 



A single spraying with Bordeaux mixture, applied at the time 

 the apples are the size of hickory nuts or larger, would prevent 

 most, if not all, of this spotting. For the Maiden's Blush, Grimes, 

 and Belmont, and fair-skinned varieties generally, the spraying 

 should be done earlier to avoid russeting the fruit. 



Spongy dry rot (Volutella fructi). This disease shows itself 

 as a rotten black spot which increases in size until it eventually 

 encompasses the whole fruit. The central and older portions of 

 the decayed region are of an intense coal-black color, while the 

 younger region — the outer border, which is about five eighths of 

 an inch wide — is brownish. 



Close inspection reveals the presence of slightly elevated pimple- 

 like places in the cuticle. These are found to within about one fourth 

 of an inch of the edge of the spot, and become larger and more pro- 

 nounced as the center of the spot is approached ; indeed, the black 

 color of the spot seems to be due to the large number of these pimples 

 crowding its surface. In many instances there is no other pecu- 

 liar development and the disease might readily pass for the ordi- 

 nary black rot, caused by Sphseropsis, and doubtless is often taken 

 for it. In the older spots, however, the pimples break through 

 the cuticle of the apple, each appearing as a small wartlike excres- 

 cence, which a good lens shows to be thickly covered with stiff 

 black hairs. These hairs are the chief characteristic of this disease, 

 and when present serve to distinguish it from Sphaeropsis rot. An 

 open apple shows a brownish zone, the latest-affected part, around 

 a black area. Although the decayed portions are softer than the 

 healthy ones, this is in no sense a wet rot, the softness being a 

 spongy dryness rather than any watery breaking down of tissue. 



Diseases affecting the Fruit in Storage 



Pink rot (Cephalothecium roseum). This fungus, which has been 

 so destructive to apples in many parts of the country, is very char- 

 acteristic in appearance and is frequently called the " pink fungus " 

 by fruit-growers. The examination of an apple affected by this 

 disease in its more advanced stage will disclose one or more pink 

 spots somewhat circular and sunken. Around the fungus and in 

 the edge of the depressed portion the skin is brown. 



