APPLE DISEASES 



37 



found at any place on any or all sides. Injuries may occur at 

 any height on a tree ; at the crown, the injury known as crown- 

 rot or collar-rot; at the crotch, crotch-injury; on the main 

 limbs as they diverge from the crotch, known as sun-scald ; 

 at the roots, root-injury. The tips of branches are sometimes 

 killed back for some distance. Not infrequently the injury 



may extend from 



the collar to the 

 head, involving 

 large areas. 



Crow n-r o t, or 

 collar-rot, occurs at 

 the crown or base 

 of the trunk at the 

 ground line. It is 

 distinguished from 

 sun-scald and 

 crotch-injury by its 

 position on the tree. 

 It is normally an 

 early form of win- 

 ter-injury. Obser- 

 vations indicate 

 that it may occur 

 from October to 



FIG. 8. Apple-tree nearly dead as a result of low 

 temperature injury. 



December in the 

 latitude of New 

 York, Ohio and Connecticut. The Tompkins King, Grimes 

 and Hubbardston are most subject to crown-rot. In such 

 injured places the bark appears discolored, dead and loosened 

 from the trunk, sometimes split open, exposing the wood. 

 Again the injured bark clings to the wood for a time, forming a 

 canker at the crown. 



Sun-scald is usually made evident in the late spring by the 



