has appeared at irregular intervals with increasing severity in various 

 sections of the more southern parts of the apple belt. In recent years 

 the losses from this malady have been specially severe, amounting 

 during some seasons to several millions of dollars. The fact that it 

 may suddenly attack and destroy the entire crop of an orchard as the 

 fruit approaches maturity has brought about a general dread oi the 

 trouble, and has caused a depreciation in the value of orchards in 

 infested regions. 



DESCRIPTION. 



The disease first appears on the fruit as very minute yellowish- 

 brown spots, frequently surrounded by purplish or reddish areas. 

 These spots, which are circular in outline, gradually enlarge, assume a 

 dark brown color, and, owing to a shrinking of the invaded tissue, 



Fig. 1.— a Yellow Newtown apple affected with bitter-rot, and a mummified fruit of the preceding 



year's crop. (From Scott.) 



become more or less depressed. By the time the spots reach one- 

 fourth to one-half inch in diameter, minute, black, slightly raised 

 fruiting pustules begin to appear, arranged in more or less concentric 

 rings. These soon break through the skin, discharging pinkish 

 masses of spores, and as the disease advances other rings of pustules 

 are produced. The pink spore masses are more in evidence during 

 periods of fairm^eather, as they are readily washed off by rains and are 

 even dissolved out by heavy dews, leaving visible the small black 

 openings of the pustules. 



Only a single diseased spot may appear on an apple, but frequently 

 there are several of varying sizes, and in a serious outbreak the fruit 

 may be literally peppered with small points of infection and numerous 

 larger spots. In such cases a few of the spots grow rapidly and envelop 

 the others, and, although coalescing more or less, retain their individual 



283 



