is8 Bulletin 395 



the plant. It is known also as cane rust, spot, scab, or sun-scald. It 

 occurs on all the above-named species of Rubus and their hybrids, and 

 in addition is found on various other species of this genus, such as the 

 blackberry {Rubus sp.), the eastern and the western dewberry {Rubus 

 villosus Ait. and Rubus vitif alius Cham. & Schlecht.), the cloudberry 

 {Rubus chamaemorus L.), and the European bramble {Rubus Jruticosus L.). 

 Halsted (1894)^ has suggested that the anthracnose of the rose may be 

 identical with that of the raspberry, but this has not been proved. 



Of the species of Rubus affected by anthracnose, the black raspberry 

 (Rubus occidentalis) exhibits the greatest susceptibility to the disease. 

 On this species the disease is very severe, not only on the cultivated 

 varieties but also on the wild forms. Observations show, moreover, 

 that the hybrid generally known as Rubus neglectus has inherited this 

 susceptibility, and anthracnose occurs commonly in plantations where 

 this hybrid is grown. On the other hand, the commercial varieties of 

 the red raspberry, which arise mainly from Rubus idaeus var. aculeaiissimus , 

 show a marked resistance to the disease. Very few fields planted with 

 these varieties have been observed where the anthracnose was considered 

 to be of any economic importance. Furthermore, it is noticeable that 

 on the wild forms of this species the disease seldom occurs except on the 

 leaves, where it is never serious. In New York State the blackberry 

 is rarely subject to anthracnose, but according to Lawrence (19 10) and 

 Jackson (19 13) it is very susceptible to the disease in the northwestern 

 United States. Anthracnose is more or less injurious also to the dew- 

 berry and the loganberry. 



Varietal susceptibility is not markedly perceptible within the above- 

 named species. Taylor ^ reports a desirable black raspberry, the Hoosier, 

 which is considered to be resistant; at least it has remained free from the 

 anthracnose disease up to the present time. Among the varieties of the 

 red raspberry the Cuthbert is held to be the most resistant, though all 

 the varieties of this species exhibit but very little susceptibility. The 

 Coltmibian, a purple-cane variety, formerly was regarded as nearly 

 immune, but it now exhibits a marked susceptibility. It is not known 

 whether this variety really possessed resistance at one time or whether 

 the stock was merely free from the disease. At present very few growers 

 recognize any difference in susceptibility between the black raspberry 

 and the purple-cane varieties. Lawrence (19 10) states that among 

 the varieties of blackberry the disease is severe on the Snyder and the 

 Kittatany, while on the Himalaya Giant it occurs only on the leaves. 



• Dates in parenthesis refer to bibliography, page 182. 



' Taylor, William A. Hoosier raspberry. In Promising new fruits. U. S. Dept. Agr. Yearbook 

 1010:429-430. J9it. 



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