New York Agricultural Experiment Station. 197 



We have seen no severe case of gumming except that caused 

 by the fruit bark-beetle, Scohjtus. In September, the gumming 

 of peach trunks due to the attacks of Scohjtus was very general 

 in Niagara County. For an account of this see Bulletin 180 of 

 this Station. 



Crown gall occurs frequently on nursery stock and occasionally 

 on orchard trees. 



We have seen no powdery mildew, Sph(srotheca pannosa 

 (Wallr.) Jj6y., the past season. 



PEAR DISEASES. 



FiREi Blight (Bacillus amylovm'us (Burr.) De Toni.), — This dis- 

 ease was common and did considerable "damage, but not as much 

 as usual. 



Leaf Scorch. — On August 12 we observed at Geneva a black- 

 ening of pear leaves which resembled the work of fire blight, but 

 was, in realitv, due to leaf scorch. The trees on which it 

 occurred were of the variety Kieffer, about ten years old, other- 

 wise healthy and growing rapidly. Over a considerable portion 

 of the tops of many trees the leaves were black and dead. For 

 the most part, the injury was confined to about two or three feet 

 of the terminal portion of vigorous shoots of the present season's 

 growth. Only the leaves were affected. The wood was unin- 

 jured and this fact is proof that the trouble was not fire blight. 

 In the course of about two weeks most of the blackened leaves 

 fell and the injury was then less conspicuous. 



We are convinced that it was weather injury similar to the leaf 

 scorch which appeared on cherries in 1899; but we are at a loss 

 to account for its occurrence this season when cherries have been 

 free from the trouble; whereas, in 1899, cherries suffered from 

 leaf scorch when pears were exempt from it. We know posi- 

 tively that the Kieffer orchard affected with leaf scorch in 1900 

 was wholly free from it in 1899. Even pear trees mingled with 

 the badly scorched cherry trees in the Maxwell orchard in 1899 

 showed no signs of leaf scorch.^^ 



"See Bui. 162 of this Station, p. 173. 



