474 DISEASES AXD INSECTSo 



CHAPTER m. 



DISEASES AND INSECTS. 



Section 1. — Diseases. 



The Fire-Blight of the Pear^ Apple, and Quince. — 

 Tliis is one of the most formidable diseases to wliich fruit- 

 trees are liable. Whether it is caused by the sun, the 

 atmosphere, or an insect, remains in doubt, some cases 

 favoring one opinion, some another. It attacks the trees 

 at different periods of the growing season, from June to 

 September, and generally in the young parts first ; the 

 leaves flag, the sap becomes thick and brown, oozing out 

 in globules through the bark, and emitting a very dis- 

 agreeable odor, and the diseased branch or part turns 

 black, as if it were burned by fire. When the pear-tree 

 is attacked it is diflicult to save it, tlic disease spreads so 

 rapidly. In the apjde and quince it is less fatal, rarely 

 killing more than a portion of the tree even if left to its 

 own course. The only remedy is, to cut away instantly 

 the blighted parts, into the sound wood, where there is 

 not the slightest trace of the disease, and burn them up 

 immediately. 



It is thought by some that young trees growing very 

 rapidly are more subject to it than older trees growing 

 slowly ; and that warm sunshine, with a sultry atmosphere 

 after rain, is apt to be followed by much blight. We have 

 always regarded the cases favoring such an opinion as 

 accidental. 



Tioig Blight, — This attacks the young shoots of the 

 current season's growth on apple, pear, quince, mountain 

 ash, etc., causing them to suddenly wither and become 



