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 common 
form of the disease in New York |__| 
State. The most striking symptom Fic. 85. — Fire-blight; the 
to be recognized by the grower is cee Bae: spread trom The 
2 : ossom into a twig, forming a 
that of twig-blight (Fig. 86). In canker. 
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 
