M Mil IMPERFECT] 



165 



LIII. LEAF BLIGHT OF PEAR AND QUINCE 

 Entomospotiutn maculatum Lev. 



DUGGAR, B. M. Some Important Pear Diseases. II. Leaf Blight. Cornell 



Agl. Exp. Sta. Built. 145: 611-615. 1898. 

 FAIRCHILD, D. G. Experiments in Preventing Leaf Diseases of Nursery 



Stock in Western New York. N. Y. Agl. Exp. Sta. Kept. 11 : 642-652. 



1892. (Also, Journ. Myc. 8: 338-351.) 

 Si RinxER, F. L. Leaf-Blight and Cracking of the Pear. U. S. Dept. Agl. 



(1888): 357-364- 



Habitat relations. The leaf blight of the pear and quince has 

 been observed in this country as well as in Europe for many years ; 

 it has also received considerable attention at 

 various agricultural experiment stations in pear- 

 producing regions. In New York it is most 

 abundant apparently in the Hudson Valley, and 

 in general it would seem to be more injurious 

 in states in the Appalachian region. Nearly 

 all varieties of pear are affected, but Duchess 

 and Kieffer are perhaps the most resistant of 

 those ordinarily grown. Moreover, in different 

 regions of the Atlantic states there seems to be 

 a difference in the susceptibility of varieties. 

 Considerable damage may also be done in the 

 nurseries to seedling pears, although grafted 

 stock is far more subject to the leaf spot than 

 to the leaf blight. Root suckers on seedling 

 pears throughout the country are very generally 

 injured. The spots are sometimes noticed on 

 the tips of young branches, and it has been very definitely shown 

 that in such situations the fungus may readily pass the winter. 

 The effect of the disease upon seedlings is to harden the wood 

 early and prevent the best results from budding. 



Symptoms. The spots produced by this fungus are particularly 

 evident on the upper surfaces of the leaves, occurring first as small 

 discolored areas which become dull red at the center, with dark 

 borders. They are more or less circular in outline, but they may be 

 closely clustered and considerably confluent. In severe attacks the 

 leaves may become yellow or brown, and they readily fall. This 



FIG. 183. EXTOMO- 



SPORIUM ON PEAR 



(Photograph by 



Geo. F. Atkinson) 



