334 



FUNGOUS DISEASES OF PLANTS 



may be induced by Glomerella rufomacidans , the fungus of bitter 

 rot ; but the typical anthracnose has not been produced by inocu- 

 lations with the apple fungus. Moreover, the species here discussed 

 seems to be more closely restricted in its conditions of growth. 

 Upon artificial media it grows slowly and with less vigor than is 

 commonly the case with many species of anthracnose. 



Control. Experiments concerned with the prevention of this dis- 

 ease indicate that the usual spraying operations as recommended 

 for the black rot are not necessarily effective for the anthracnose. 

 Nevertheless, it is doubtful, under ordinary circumstances, if other 

 precautions need be taken. When the fungus appears in an epi- 

 demic form it will be necessary not only to spray repeatedly with 

 Bordeaux, but also to prune out and burn as promptly as possible 

 the diseased canes and fruit bunches. 



XXXIV. ANTHRACNOSE OF RASPBERRY AND BLACKBERRY 

 Glcsosporium Venetum Speg. 



Detmers, Freda. Anthracnose of Raspberry and Blackberry. Ohio Agl. 



Exp. Sta. Built. 4 (No. 6): 124-126. pis. 3-4. 1891. 

 Paddock, W. Anthracnose of the Black Raspberry. N. Y. Agl. Exp. Sta. 



Built. 124: 261-274. l8 97- 

 Scribner, F. L. Anthracnose of the Raspberry and Blackberry. U. S. Dept. 



Agl. Rept. (1887): 357-367- pi. 5- 



This fungus produces the well-known anthracnose of raspberries 

 and blackberries (R?tbus spp.), characterized by injuries of the 

 canes. Raspberries are commonly more seriously affected. Small 

 purplish spots appear at first, later the center becomes gray and 

 sunken, giving somewhat the bird's-eye effect. Petioles and veins 

 of leaves may also be affected, and the injuries are severe. Minute 

 spots sometimes appear on the blade of the leaf. The acervuli 

 appear frequently in the older spots. Control measures have not 

 been as effective as may be possible. The pruning out and destruc- 

 tion of diseased canes is essential, and thorough spraying with 

 Bordeaux may be practiced during the early part of the season. 

 Spraying alone is not ordinarily sufficient for the proper control 

 of this disease. Healthy plants only should be set, and a short 

 rotation practiced. 



