454 Report of the Mycologist of the 



were trees with well-established root systems. The common 

 practice of horticulturists in pruning away large portions of 

 the tops of plants, especially conifers, at the time of transplant- 

 ation, is based upon the same principle; the object being to re- 

 duce the transpiring surface to the mimimum until the plant can 

 establish a root system. 



The Norway maple is much planted as a shade tree on Long 

 Island, and seems to be well adapted to both the soil and the cli- 

 mate; but it suffered more from the dry wind than did any other 

 common tree. The white pine was somewhat affected, and Mr. 

 Nicholas Hallock called our attention to pear and apple trees 

 which were slightly injured from the same cause. 



The Gercospora Leaf-Spot of Tilia. 



For two years past several species of Tilia (Linden) in the 

 Long Island nurseries have been attacked by a leaf-spot disease 

 which disfigures the foliage and causes the leaves to fall pre- 

 maturely. It is caused by the fungus, Gercospora microsora, Saco. 

 In the Botanical Gazette for 1881, Prof. Peck* has described the 

 same fungus under the name Gercospora Tiliw. 



The common fungicides should control the disease. 



Phyllosticta limitata Pk. 



In our lasl Report f this fungus was reported as destructive 

 in 1895. During the past season it has been more abundant than 

 ever, and must be placed in the list of serious orchard pests. 

 More or less of the disease may be found in almost any orchard 

 on Long Island, and in some it has defoliated the trees. The 

 generally unhealthy condition of Long Island apple orchards is 

 probably largely due to the attacks of this fungus. Year after 

 year the leaves fall prematurely, sometimes as early as the middle 

 of July, and the trees become gradually weakened. In the re- 

 port previously mentioned, it was stated that the three spray- 



*Peck, C. H. New species of Fungi, Botanical Gazette, Vol. vi, p. 277. 



+ Stewart, F. C. A New Leaf -spot Disease of Apples. Fourteenth Ann. Rept. New York 

 Exp. Sta , p. 545. 



