CHERRY: DISEASES 173 
enter the next season with decreased vitality. A case is on 
record where 40,000 young cherry trees were lost on account 
of leaf-blight alone. The loss in Ohio in 1905 is estimated at 
$25,000. The preceding year it is estimated to have caused a 
loss of 8 per cent, in Maryland. One nursery company in 
Fic. 48. — Leaf-blight (yellow-leaf, or leaf-spot) on sweet cherry; types of 
lesions on upper and lower surfaces. Center leaf shows whitish masses (spores) 
of the pathogene. 
Nebraska claims to have lost $40,000 in 1903 on account of. 
this disease. 'These examples serve to show the possible destruc- 
tion which may be wrought by leaf-blight. 
Symptoms. 
The fruit and pedicels are liable to show the disease, but the 
foliage (Fig. 48) is by far the most common seat of the trouble. 
Toward the last of May or early in June affected leaves exhibit 
slightly discolored, dark-blue areas on the upper surface (Fig. 
48, left). These are not more than one-eighth of an inch in 
