FUNGI AFFECTING THE RASPBERRY 

 AND BLACKBERRY 



The Raspberry Anthracnose 



Glceosporium venetum 



Although this fungus is a widespread enemy of 

 raspberries and blackberries, public attention was first 

 called to it only about twelve years ago, when Professor 

 T. J. Burrill published an account of it, under the name 

 Raspberry Cane Rust, in the Agricultural Review. 

 Fruit growers frequently call the disease "sun scald," 

 but its more proper name is anthracnose. 



This fungus especially infests blackcap raspberries 

 and the thornless varieties of blackberries. It appears 

 both upon the canes and leaves. On the former it may 

 generally be found late in spring or early in summer on 

 the young shoots, when about a foot high, in the shape 

 of small reddish-purple "spots, scattered irregularly over 

 the surface near the ground. As the canes grow these 

 spots increase rapidly in size, their centers becoming 

 grayish- white, and other spots appearing on the upper 

 portions. There is an elevated dark purple margin 

 around each spot, representing the division between 

 healthy and diseased tissues. As the season advances 

 the spots continually enlarge, many of them finally run- 

 ning together to form irregular longitudinal blotches, 

 which sometimes run clear around the cane and thus 

 girdle it. The injury extends through the outer bark, 

 frequently rupturing it, and sapwood (cambium layer), 

 but usually does not penetrate the pith. As the tissue 

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