PEAR DISEASES 333 
of those varieties already mentioned. The Kieffer shows con- 
siderable resistance in some parts of the country. 
Pear-scab occurs practically everywhere the fruit is grown. 
It was found in Belgium in 1832, but was not reported as doing 
great damage until 1875. Elsewhere in Europe scab prevails 
commonly on the pear. In the United States outbreaks occur 
in New England, the Middle West and along the Pacific Coast. 
It was particularly destructive in 1906 over the country gen- 
erally ; in 1898 it was epiphytotic in Ohio; in 1902, 1910, 1912 
and 1915 it was unusually prevalent in New York; while it 
prevailed extensively in California in 1904, 1905 and 1906. 
Symptoms. 
The disease is found on the fruit, leaves and twigs. On the 
fruit (Fig. 92) the spots are at first olivaceous, velvety and 
4 4 
te 
Fic. 92. — Pear-scab. 
circular in form. Later in the season this velvety aspect be- 
comes corky and the skin is cracked, sometimes in a T-shape 
fashion (Fig. 92). At times growth of the young fruit is halted, 
and so when such pears are mature they are considerably 
distorted. Affected fruit may drop when the size of a cherry. 
