FUNGI AFFECTING THE STRAWBERRY 



The Strawberry Leaf=blight 



Sphcerella fragarice 



The strawberry leaf-blight, leaf-rust, or leaf-sj^ot 

 is the most destructive of the numerous fungous ene- 

 mies of this delicious fruit. The disease aj^parently 

 occurs in the United States wherever strawberries are 

 grown, having been recorded from Maine in the north 

 and east, to Florida in the south, and California in the 

 west. Over a large portion of this vast territory it fre- 

 quently becomes very seriously injurious. 



This fungus first appears on the upper surface of 

 the leaf in the shape of small purplish or reddish spots, 

 which, though minute at the start, increase rapidly in 

 size. Their centers also gradually become lighter in 

 color, changing from purple, or reddish, to brown, then 

 to gi'ay or white, but the margin generally remains pur- 

 ple. The size of the spots varies greatly, single ones 

 sometimes being a quarter of an inch in diameter, and 

 others running together to form large discolored blotches. 

 Badly affected leaves finally wither, turn brown and die. 

 The vitality of affected plants is seriously impaired, and 

 if they are not killed outright, the crop of fruit pro- 

 duced by them is diminished. 



Professor H. Garman says that if one of the dis- 

 eased spots ^^be cut through with a pair of fine scissors, 

 the leaf will be found, at the point where the spot is 

 formed, much thinner than elsewhere, because of the 

 killing and drying out of its substance. Examined 

 under a microscope the fungus may now be found to 



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