PEAR : DISEASES 353 



RED LEAF 



Cause not definitely known 



This peculiar and interesting disease has been observed in 

 New York State during the past five or six years. There are 

 no extensive data as to its preference for varieties, although it 

 has been observed especially on the Kieffer and Clairgeau. 

 In some cases under attention the orchards showing red-leaf, 

 or crimson foliage, were located on a hillside, and the disease 

 was confined to those individuals occupying the lower part of 

 the orchard. Such trees also exhibit signs of general unthrifti- 

 ness. Affected trees stand out prominently among their 

 healthy neighbors and exhibit an entire foliage discoloration; 

 a dark or purplish red color. The suggestion has been made 

 that lack of vigor, of which red-leaf is a sign, may be due to one 

 or more factors. Such factors worthy of note are poor under- 

 drainage, insufficient plant food, a diseased condition of the 

 trunk or roots, and winter and drought injuries. 



REFERENCE 



Stewart, F. C. Notes on New York plant diseases, I. Pear. Crimson 

 foliage. New York (Geneva) Agr. Exp. Sta. Bui. 328 : 371-372. 

 1910. 



