CHERRY DISEASES 187 
Crown-GaLL 
Caused by Bacterium tumefaciens E. F. Smith and Townsend 
The crown-gall disease is so cosmopolitan in its host-range 
that the cherry could not be expected to escape in all cases. 
It is the younger trees that suffer, particularly if the knots, or 
galls, surround the crowns. In the North, at least, it has been 
observed that little injury is done to mature trees. Sometimes 
trees planted with galls may outgrow the disease in a year or 
so. It is not safe, however, to assume that this will always 
occur; affected trees should not be used in plantings. (See 
fuller discussion under Apple, page 108.) 
ARMILLARIA Root-Ror 
Caused by Armillaria mellea (Fries) Quel. 
Among the stone fruit-trees affected by this root-disease the 
cherry stands out as one of the most resistant. In the Pacific 
Northwest, however, a few cases of root-rot caused by Armillaria 
mellea have come to the attention of growers and plant patholo- 
gists. Special discussion is not necessary here; see Apple, 
page 96. 
Lear-Rvust 
Caused by Puccinia Pruni-spinose Pers. 
On the leaves of many wild and cultivated cherries there is 
frequently a rust-disease. It is said to occur more commonly 
in the eastern United States. The same disease is found on 
the peach and on wild and domesticated forms of the plum. 
It is variously known as plum leaf-rust, prune-rust, peach-rust 
and leaf-rust of cherry. (See fuller. account under Plum, 
page 377.) 
