BOARD OF HORTICULTURE 



129 



dark spot in tlie bark, wliich enlar.«;es tlirouKli tlie winter uutil by early spring 

 it reaches a maximum size of perhaps two to six or eight inches in length and 

 attains an elongated sliape. As soon as the tree beeomes active in the spring, 

 the canker is checktnl in its further growth and a craok appears around the mar- 

 gin. The healthy bark around it grows and the canker commences to dry out, 

 being left as a sunken dead strip of bark. The damage caused by a Single canker 

 on a branch seldom amounts to mucli, although sometimes small twigs may be 



K ■^''>! 



-i 



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AN ANTHRACNOSE RUINED ORCHARD 



girdled and killed. The infections, however, often occur in great numbers and 

 close together, so that the cankers unite and thus bring about the death of great 

 Stretches of bark, which may completely girdle large limbs or even the trunks of 

 young trees. witli the result that the parts beyond eventually die and the tree is 

 seriously crippled. 



As the season goes on, the dead canker bark shows little raised pimples which 

 break open I»y tiny craeks at the top. These are the spore cushions, from each of 

 which a crop of spores is produced. It is tlie part of wisdom to remove as much 

 of this dead canker bark as possible from the orchard before the fall, so as to get 



Sig. 5. 



