272 



MANUAL OF FRUIT DISEASES 



the set of fruit; (2) twigs may be blighted, thus inflicting 

 serious injury on the tree ; (3) large limbs may be cankered, 

 which form of the trouble is of great importance in parts 

 of New York State ; (4) the crop of fruit itself may be par- 

 tially or wholly destroyed as a result of attacks by the 

 brown-rot pathogene ; green fruits, if injured by insects or hail, 

 may be rotted extensively ; and likewise ripe fruits on the tree, 



in transit, or in 

 market may be 

 wholly ruined as a 

 result of rotting. 

 Symptoms. 

 The fruits are 

 most commonly 

 affected (Fig. 71). 

 However, other 

 organs of the 

 host are also sus- 

 ceptible to the 

 disease ; these in- 

 clude the blos- 

 soms, twigs, limbs 

 (Figs. 72 and 73) 

 and occasionally 

 the leaves. 



In America the 

 flowers are com- 

 monly affected, 

 resulting in a serious blossom-blight. When the blossoms are 

 opened, the petals turn brown and shrivel, but do not fall. Gray- 

 ish tufts composed of the fruiting structures of the pathogene 

 show on the affected blossoms. Twig-blight follows blossom- 

 blight very closely, the former being a direct result of the latter. 

 The leaves on such twigs wither and die and cling to the twig, 



FIG. 72. Brown-rot canker of peach, general 

 appearance in the orchard. 



