New York Agricultural Experiment Station. 205 



or leaf curl (Exoascus) or of scab {Cladosporium carpopliilum) 

 were taken. There is a disease of Japan pliimfi which resembles 

 peach jellows, but we have had little opportunity to study it. 



QUINCE DISEASES. 



Leap Blight and Fruit Spot {Entomospm^kim ntaeulatum 

 JAy). — Correspondents report considerable damage done by this 

 disease; still we believe that it has been much less destructive 

 than usual. While .the fungus attacks the fruit as well as the 

 leaves it is on the latter that it does the most damage. 



We have frequently observed that on quince leaves the Ento- 

 mospm^ium spots are of two sorts: (1) The typical sort, which 

 is brown, 3 millimeters or more in diameter and bears at the 

 center a black pimple, the acervulus, commonly visible only on 

 the upper surface of the leaf. Two or more such spots may 

 coalesce to form a still larger spot with two to several acervuli. 

 (2) Small black spots, each bearing a single black acervulua 

 which occupies nearly the whole of the spot and is usually visi- 

 ble on both sides of the leaf. Curiously enough the acervuli on 

 the small spots are somewhat larger than those on the large spots, 

 but otherwise they do not differ. 



Canker and Black Kot (Sphwropsis malorum Pk.) — Some of 

 the quince orchards are seriously affected with canker of the 

 trunk and larger branches. In April we found Spliwropsis 

 malorum Pk. fruiting abundantly on cankered limbs. There 

 seems to have been very little black rot of the fruit. 



Powdery Mildew {Padosphwra oxyacantlim (DC.) D By). — In 

 August we observed powdery mildew on quinces at Geneva and 

 Penn Yan. At the latter place it was abundant on nearly every 

 tree in a large orchard of young thrifty trees, but apparently it 

 was doing them no damage. We also observed traces of this fun- 

 gus on quinces at Geneva in 18&9. 



It occurred only on the upper surface of the leaves and showed 

 a decided preference for the older leaves, rarely attacking the 

 young leaves of the new growth. In both these respects it is in 

 direct oantrast with the powdery mildew ob oherry, which ia 



