156 



MANUAL OF FRUIT DISEASES 



of an attack prior to blossoming. Recent records indicate that 

 the disease is not easily controlled. (More complete discussion 

 under Peach, page 311.) 



REFERENCES ON CORYNEUM FRUIT-SPOT 



Smith, R. E. Report of the plant pathologist. Apricot disease 



investigation. California Agr. Exp. Sta. Bui. 203 : 33-37. 1909. 

 Stewart, F. C., Rolfs, F. M., and Hall, F. H. A fruit disease survey 



in western New York in 1900. New York (Geneva) Agr. Exp. Sta. 



Bui. 191 : 305. 1900. 

 Smith, R. E. California plant diseases. Apricot. Shot-hole and 



fruit spot. California Agr. Exp. Sta. Bui. 218 : 1095. 1911. 



RUST 



Caused by Puccinia Pruni-spinosce Pers. 



FIG. 43. Apricot-rust. 



This is a disease of 

 stone-fruits in general. 

 On the apricot it is espe- 

 cially prevalent in Cal- 

 ifornia. Reddish brown, 

 dusty pustules are pro- 

 duced on the lower 

 surfaces of the leaves 

 (Fig. 43). This occurs 

 late in the summer. The 

 causal fungus, Puccinia 

 Pruni-spinosa, may in- 

 duce premature defolia- 

 tion in cases of severe 

 infection. (See full discus- 

 sion under Plum, page 377. 

 See also Cherry, page 187, 

 and Peach, page 319.) 



