EXPERIMENT STATION BULLETINS. 



387 



when once it gains an entrance into the tissues of the host. Hence plants which 

 are once attaclved rarely recover. Any plant, therefore, which shows the char- 

 acteristic orange colored blisters on its foliage should be dug out and burned 

 at once else it will serve as the breeding place of the parasite. Neither should 

 young plants be taken from among those infested with the fungus as they too 

 will in all probability be affected. Keeping the foliage covered with some fungi- 

 cide, as Bordeaux mixture early in the season will tend to prevent infection of 

 the healthy plants. 



Fig. 37. — Canes of raspberry, showing spots produced by the Anthracnose fungus. (Original.) 

 ANTHRACNOSE OF RASPBEREY AND BLACKBERRY. 



(Gloeosporium venetum Speg.) 



The anthracnose of 'raspberry and blackberry is a common disease of these 

 plants and one which is capable of doing much harm. It affects the canes first, 

 later appearing also on young shoots and leaves. The spots in the early stages 

 of the disease are purple but as the disease progresses these spots acquire a 

 whitish center and become somewhat sunken. In bad cases the spots run to- 

 gether sometimes encircling the cane; at other times they run along one side 

 producing large patches of a grayish color. During the second season the spots 

 tend to dry out, producing cracks in the wood and scaling of the bark. 



On the leaves the spots are apt to be small but numerous and follow the general 

 appearance of those on the canes. 



The effect of this parasite is to reduce the vigor and size of all parts of the 

 plant. The fruit often fails to mature properly but frequently dries up before 

 ripening. 



Treatment should consist of cutting out the worst diseased canes and spraying. 

 Beginning in spring the first application may be the copper sulphate solution 

 before the leaf buds open. The second, soon after the foliage is out, with Bordeaux 

 mixture. A third spraying with the Bordeaux should follow the harvesting of 

 the crop. Start new plantations from healthy canes or from root cuttings in 

 case of red raspberry and blackberry. 



