PLUM DISEASES 377 
Industry in New York State. New York Agr. Dept. Bul. 79: 
1198-1199. 1916. 
Swingle, Deane B. The botany and bacteriology department. In 
rei of Director. Montana Agr. Exp. Sta. Rept. 22: 241. 
Atkinson, G. F. Leaf curl and plum pockets. Ezoascus Pruni Fekl. 
Cornell Univ. Agr. Exp. Sta. Bul. 73 : 329-330. 1894. 
Selby, A. D. Some diseases of orchard and garden fruits. Plum 
pockets. Ohio Agr. Exp. Sta. Bul. 79:117. 1897. 
Rust 
Caused by Puccinia Pruni-spinose Pers. 
On the leaves of many stone-fruits is produced a rust disease 
known as plum leaf-rust, prune-rust and rust of stone-fruit trees. 
The disease is widely distributed in North America, Europe and 
Asia, and is common in South America, Africa and Australia. 
In the United States it is reported from most of the states east 
of the Mississippi River, and from Iowa, Missouri, Oklahoma, 
Texas, Louisiana, California and Oregon. It doubtless occurs 
in other states of the Union. In Europe it is found in Germany, 
France, England, Italy, Austria, Belgium and Switzerland. 
These statements indicate the cosmopolitan occurrence of plum 
leaf-rust throughout the world. 
Outbreaks of this disease are not uncommon. ‘In 1886 the 
troublesome nature of plum-rust attracted attention in Aus- 
tralia; in 1889 it was serious in Iowa; and in recent years it 
has been the object of experimentation in the far West. In 
severe cases defoliation may occur; this is true of the prune and 
peach in California and of the peach in Texas. It is more 
destructive in warm, moist climates where crops are seriously 
impaired and where trees are said to die within three or four 
years after the attack. In the United States most damage is 
done in the southern portion, and of all trees affected the plum 
suffers most. Chippewa plums are said to be particularly 
susceptible. Likewise the Imperial Ottoman is badly affected. 
