358 FUNGOUS DISEASES OF PLANTS 



XLIX. LEAF SPOT OF THE PEAR 

 Septoria Pyricola Desm. 



DUGGAR, B. M. Some Important Pear Diseases. Leaf Spot. Cornell Agl. 

 Exp. Sta. Built. 145: 59?-6n. figs. I57~ l6 5' l8 9 8 - 



The leaf spot of pear is a disease which may be readily dis- 

 tinguished from the leaf blight subsequently described. It occurs 

 throughout the eastern United States as an important fungus, both 



FIG. 176. LEAF SPOT OF PEAR 



in orchards and nurseries. It is probably found throughout North 

 America and is reported from various parts of Europe. 



The leaf spot fungus is confined to the leaves, and in orchards 

 the chief injury to trees may be the reduced vigor for the next 

 season, due to premature defoliation. It is rather remarkable that 

 while seedling apple stock in a nursery may show leaf blight to a 

 considerable extent, adjacent plots of budded plants may be seri- 

 ously injured by the leaf spot. The budded stock of the second 

 year usually suffers more severely, particularly since it is generally 

 less cultivated after the first season. In the state of New York 

 most of the standard varieties may be attacked. Bosc, Anjou, 

 Clairgeau, Seckel, Bartlett, etc., may be considerably injured, but 

 Flemish Beauty, Duchess, and Winter Nellis are more resistant. 



