CEDAR APPLES AND APPLE RUST (GYMNOSPORANGIUM) 401 



hope, however, seems to be in breeding and selecting varieties of 

 grains which can resist the attack of the Rust, and some progress 

 has already been made in this direction. 



Cedar Apples and Apple Rust (Gymnosporangium). 1 There 

 are several Rusts belonging to this group, but the one producing 

 Cedar Apples and the Rust 

 on Apple trees is the most 

 common and the most im- 

 portant of the group. It is 

 common in nearly every 

 region where Red Cedars 

 grow, but does most damage 

 to fruit trees in the Eastern 

 and Southern states. It lives 

 a part of its life cycle on the 

 Cedar, producing gall-like en- 

 largements on the branches, 

 and a part of its life cycle on 

 the Apple tree where it at- 

 tacks the leaves and fruit, 

 often causing much damage 

 to the fruit (Fig. 358). It 

 is the gall-like enlargements 

 on the Cedar tree that are 

 called Cedar apples, although 

 they are not apples at all. 

 In Figure 359 are shown 

 Cedar apples as they appear 

 in the winter. In the spring 

 gummy branches containing 

 many teleutospores develop on these galls which then look like 

 the one shown in Figure 360. The teleutospores produce basidio- 

 spores which are blown to the Apple tree where they start the 



1 The Cedar-Apple Fungi and Apple Rust in Iowa. Bulletin 84, Iowa 

 Agr. Exp. Sta., 1905. 



The Life History of the Cedar Rust Fungus Gymnosporangium juniperi- 

 virginianae. Annual Report 22, pp. 105-113, Nebraska Agr. Exp. Sta., 1909. 



Apple Rust and its Control in Wisconsin. Bulletin 257, Wisconsin Agr. 

 Exp. Sta., 1915. 



The Cedar Rust Disease of Apples caused by Gymnosporangium juniperi- 

 virginianae Schw. Technical Bulletin 9, Virginia Agr. Exp. Sta., 1915. 



i m .,; l 



FIG. 359. Cedar Apples on the 

 Cedar. This is the way the galls look 

 in winter. From Bulletin 257, Wiscon- 

 sin Agr. Exp. Sta. 



