PEAR DISEASES 



325 



The nature of the injury makes it difficult to obtain accurate 

 figures representing the annual loss from this disease, either 

 in a given locality or in the country as a whole. The blos- 

 soms are affected, which means a loss of the current year's 

 fruit-crop, and often that of the next on account of the death 

 of the spur. Twigs may blight in great numbers, thus destroy- 

 ing the twig-growth of the current 

 year ; this may later result in death 

 of the larger limbs bearing such 

 twigs. Cankers which may eventu- 

 ally kill the tree are produced on 

 the limbs. Finally, the fruit may 

 be attacked directly; in such cases 

 it is rendered unmarketable. 



Symptoms. 



Attacks on the blossoms result 

 in blossom-blight (Fig. 85). This 

 phase of the disease is evidenced 

 by a sudden wilting and darkening 

 of the young fruits after the petals 

 fall, followed by similar changes in 

 the spur. This is a very comnon 

 form of the disease in New York 

 State. The most striking symptom 

 to be recognized by the grower is 

 that of twig-blight (Fig. 86). In 

 the Middle West twig-blight, is the 



most common form of blight. The affected organ is black- 

 ened and bears darkened, drooping leaves, the whole ap- 

 pearing as if burned by fire. In no other diseased condition 

 of fruit trees does the foliage cling so tenaciously to the 

 dead branches. Cankers occur in the bark of the body 

 or of large branches (Figs. 87 and 88). In the winter the 

 spot is dark, smooth and sunken, the margin definite and 



FIG. 85. Fire-blight ; the 



canker. 



