48 



MANUAL OF FRUIT DISEASES 



blossom-end. In the latter case, there is produced what is 

 called blossom-end rot. Worm-holes are commonly the centers 

 of rotted areas (Fig. 10). Ordinarily only one spot occurs 

 in each fruit. Such a lesion is at first brown, and is frequently 

 referred to as brown-rot. Very often concentric zones of light 

 and dark colors of uniform width appear about the center of 

 the lesion; in these cases the disease is called ring-rot. The 

 margin of the diseased portion is distinct from that of the 

 healthy (Fig. 10), and the rotted tissues are not of unpleasant 



taste as in the case of many 



fruit decays. Later stages of 

 the disease exhibit a black 

 color, whence the name black- 

 rot. Usually by the time the 

 spot is two inches in diameter 

 small black fruiting bodies of 

 the pathogene are seen on the 

 lesion. Finally, a mummy is 

 produced (Fig. 11), which is at 

 first waxy, then dry and hard. 

 Black-rot has been confused 

 with brown-rot (Fig. 37, page 

 141), bitter-rot (Fig. 5, page 16), 

 and soft-rot (Fig. 25, page 92). Brown-rot results in a browning 

 of the affected tissues which is difficult in this stage to distinguish 

 from black-rot. Later, the brown-rot mummy may be like the 

 black-rot mummy only in that it is also black in the case of 

 certain varieties; it differs, however, in that the brown-rot 

 mummy is sometimes coal black, glossy, smooth, having no 

 black fruiting bodies, and is much less wrinkled than the black- 

 rot mummy. Bitter-rot, besides having an unpleasant taste, 

 often shows pinkish spore masses on the lesion. (Compare 

 Figs. 5, 10, and 11.) Soft-rot has an extremely softening effect 

 on the tissues and also is attended by an offensive odor. These 



FIG. 11. Apple black-rot mummy. 



