Pomaceous Fruits 67 



Unless continued, careful inspection is given, and concerted 

 action in a community maintained, but little l^enefit will 

 follow. 



Rusf*^' '*-• ^^'^ {Gymnosyorangium sps., Roestelia). — Rust 

 of pear is very similar in nature to rust of the apple, though 

 less often injurious. It consists of a summer stage and a 

 winter stage. The former produces rust on the leaves of the 

 pear, while the winter stage of the eastern form of rust pro- 



FiG. 32. — Scab on California pears bought in Raleigh, N. C. 

 Original. 



duces the familiar cedar-apple upon the cedar tree. The pear 

 rust of the West is a distinct species, with the incense cedar 

 as the alternate host. 



The remedy, as in the case of the apple, consists in re- 

 moving all red cedar trees from the neighborhood of the 

 pear orchard; thus eliminating the source of infection. 

 When this is impossible, the pear trees should be sprayed 

 with Bordeaux mixture immediately after the early rains 

 which cause the gelatinous horns to emerge on the cedar- 

 apple, and thus furnish the suppl.y of spores for the spring 

 infection. This disease of pears is particularly abundant 

 upon varieties of the Japanese strain. 



Powdery-mildews. See apple. 



