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. Bul. 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. 
Bul. 191: 305. 1900. 
Smith, R. E. California plant diseases. Apricot. Shot-hole and 
fruit spot. California Agr. Exp. Sta. Bul. 218: 1095. 1911. 
é 
Rust 
Caused by Puccinia Pruni-spinose Pers. 
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-spinose, 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.) 
Fic. 43, — Apricot-rust. 
