PLUM DISEASES 377 



Industry in New York State. New York Agr. Dept. Bui 79- 



1198-1199. 1916. 

 Swingle, Deane B. The botany and bacteriology department. In 



Report of Director. Montana Agr. Exp. Sta. Kept. 22 : 241. 



1916. 

 Atkinson, G. F. Leaf curl and plum pockets. Exoascus Pruni Fckl. 



CorneU Univ. Agr. Exp. Sta. Bui. 73 : 329-330. 1894. 

 Selby, A. D. Some diseases of orchard and garden fruits. Plum 



pockets. Ohio Agr. Exp. Sta. Bui. 79: 117. 1897. 



RUST 



Caused by Puccinia Pruni-spinosce 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. 



