STRAWBERRY DISEASES 425 
Trelease, William. The spot disease of strawberry leaves. Wisconsin 
Agr. Exp. Sta. Rept. 2: 47-58. 1885. 
Halsted, B.D. The strawberry leaf spot. New Jersey Agr. Exp. Sta. 
Rept. 1893 : 328-329. 1894. 
Bailey, L. H. Varieties and leaf blight of the strawberry. Cornell 
Univ. Agr. Exp. Sta. Bul. 79: 583-604. 1894. 
Garman, H. Some strawberry pests. The strawberry leaf-blight 
fungus. Kentucky Agr. Exp. Sta. Bul. 31:3-13. 1890. 
Jackson, H. 8. Strawberry diseases. Leaf spot. Oregon Crop Pest 
and Hort. Bienn. (Rept. 1911-1912 : 268-269. 1913. 
Wolf, F. A. Strawberry leaf blight. Alabama State Hort. Soc. 
Proc. 11: 56-58. 1914. 
Powpery-MILDEw 
Caused by Spherotheca Humuli (Fries) Burr. ' 
Strawberry powdery-mildew was first reported from Eng- 
land in 1854, at which time it was of considerable impor- 
tance. In 1885 it again became noticeable in England. The 
next year it was found in America (New York State). In 
1892 it was recorded from Massachusetts, but prior to 1896 
the disease was rarely serious in the United States. Now the 
disease is common and widespread and is capable of doing 
serious damage. 
Sometimes all varieties are affected; again certain ones are 
immune. Among the susceptible varieties may be noted: 
Paxton, British Queen, Black Prince, Jucunda, Mount Vernon, 
May King and Garrettson. On the other hand, the Noble and 
Royal Sovereign are said to be resistant. 
Symptoms. 
In the first stages the leaves are affected. They curl at the 
margin and thus expose their lower surfaces. Affected plants 
present an appearance as in need of water. Powdery, white 
growth of the mildew-pathogene appears on the lower surface. 
This is frosty and mealy in aspect. Berries are affected in 
all stages of development. They are rendered tasteless and 
