352 MANUAL OF FRUIT DISEASES 



which the scions are set. This type of trouble, while itself 

 not common, illustrates what a wound parasite like P. Cydonice 

 is capable of doing. (For fuller discussion see Apple, page 45.) 



BROWN-ROT 



Caused by Sclerotinia cinerea (Bon.) Schrot. 



Outbreaks of brown-rot due to the above-named fungus are 

 not at all common in America, although European growers 

 encounter a similar trouble frequently. It is better known on 

 the apple than on the pear in this country. The blossoms, 

 fruits and branches are susceptible, and when affected the 

 various phases are referred to respectively as blossom-blight, 

 brown-rot, and brown-rot canker. Recently a brown-rot 

 canker has been described from Oregon, but it has not been 

 definitely determined whether the fungus concerned is S. 

 cinerea or another species. 



BlTTER-ROT 

 Caused by Glomerella cingulata (Stoneman) Sp. and von S. 



Fortunately for the pear-grower bitter-rot is never as com- 

 mon and destructive to the pear as to the apple. Whereas 

 apple bitter-rot ranks second in importance only to apple-scab 

 over the country as a whole, pear bitter-rot is rare and has 

 never been found doing extensive damage. The fungus, G. 

 cingulata, was reported as causing cankers on both young and 

 old trees in Texas a few years ago. Characteristics of the 

 disease on the fruit and woody portions of the tree, together 

 with a description of the life-history and control of the patho- 

 gene, are given in some detail under Apple, page 14. 



