264 MANUAL OF FRUIT DISEASES 



RlPE-ROT 

 Caused by Glomerella dngulata (Stoneman) Sp. and von S. 



This disease is sometimes called anthracnose, but it should 

 not be confused with the anthracnose disease discussed on 

 page 249. The name bitter-rot is also used to designate this 

 trouble, although ripe-rot is preferable. 



Ripe-rot was known several years prior to 1887, at which 

 date grape diseases first received the serious attention of 

 American plant pathologists. The history of the disease 

 shows that the first observations on it in the United States 

 were made in North Carolina, although the pathogene was 

 described in England in 1854. At present the disease has a 

 general range over the grape regions of the country, but only 

 occasionally is there any wide devastation. White varieties, 

 like the Martha, are sometimes affected in a destructive fashion. 

 A characteristic of the disease which makes it annoying and 

 dangerous is that even after a crop has escaped other grape 

 diseases during the year, ripe or ripening berries may be at- 

 tacked to a considerable extent. 



Symptoms. 



Berries, canes and fruit-pedicels may be affected by ripe-rot, 

 but it is most conspicuous on the berries. Ripe grapes only 

 are affected ; or at least they are not affected until the ripening 

 period is near at hand. The diseased flesh becomes reddish 

 brown or rosy in color and the surface is sunken. Finally the 

 lesion, by enlarging in concentric zones, involves the whole 

 berry, and the result is a brown or purple mummy. The lesions 

 are more striking on light-skinned varieties. These characters 

 serve to distinguish ripe-rot from black-rot. It has been noticed 

 that ripe-rot mummies fall to the ground at the slightest jar, 

 while black-rot mummies cling tenaciously to their pedicels. 

 Affected berries are not bitter, as the name bitter-rot would 

 suggest. The name bitter-rot has been adopted in the several 



