156 TWENTY-FIFTH ANNIVERSARY REPORT. 
lent shoots causing them to suddenly wilt and die. By means of in- 
oculation experiments it was proven that a fungus belonging to the 
genus Phoma is responsible for the disease. Although no experi- 
ments have been made it is probable that stem rot may be pre- 
vented by spraying with bordeaux mixture as for anthracnose. 
STRAWBERRY, SUNFLOWER, SYCAMORE AND TURNIP. 
In the Fifth Annual Report (p. 275) is given an account of a 
powdery mildew"! found on strawberries on the Station grounds 
in the summer of 1886. This is thought to be the first record of the 
occurrence of powdery mildew on strawberries although what ap- 
pears to be the same fungus had long been known as a parasite of 
hops, dandelions and several other plants. The interesting observa- 
tion was made that while the fungus adapts itself readily to plants of 
very diverse nature it attacks the different varieties of the same 
species of dandelion in widely different degrees. 
In the Sixth Report (p. 351) there is an account of an experiment 
in which potassium sulphide, used as a spray, kept the strawberry 
leaf spot well under control. 
The Fifteenth Report contains short articles on two common 
diseases (rust and leaf spot) of the cultivated sunflower (p. 455), 
the anthracnose™ of sycamore trees which is very common and 
injurious on Long Island (p. 457), and an unusual leaf spot dis- 
ease! of flat turnips found on Long Island in 1896 (p. 451). 
TOMATO. 
The blossom end rot of the tomato has long been a puzzle to plant 
pathologists. Even at the present time it is very mmperfectly under- 
stood. It has been ascribed to various causes, scarcely any two 
investigators being in complete agreement on the subject. The 
probable explanation of this is that the symptoms may be pro- 
duced by any one of several causes. , 
While this disease has never been given extended study at the 
Station, observations and small experiments have been made upon it 
from time to time. Notes on it appear in every one of the first five 
™ Spherothica humuli (DC.) Burr. 
 Spherelia fragaric (Tul.) Sace. 
™ Glecsporium nervisequum (Fckl.) Sacc. 
™ Macrosporium herculewm E. & M. 
he 
