The Canadian Horticulturist. 



109 



THE strawbp:rry leaf blight. 



©CCASIONALLY we receive inquiries concerning the strawberry leaf 

 blight, its cause and its remedy. According to a late bulletin of 

 Cornell University, the scientific name is Sphaerella Fragarice, or the 

 Sphaerella of the strawberr}'. It has been spoken of as " spot disease," 

 *' sun scald," *' strawberry rust," but Prof. Dudley thinks the name Leaf 

 Blight most applicable. This blight first appears on the new leaves about 



Fig. 30. — Leaf of Strawberry, marked by Sphaerella Fra^arui. 



the time of the setting of the fruit, and if the weather of the succeeding 

 months be dry and hot, it causes serious injury to the vitality of the plan- 

 tation. 



Our readers will recognize this disease from the illustration given above, 

 and also when we describe the spot as at first brownish or red-purple, and 

 when fully matured it has a circular centre, dead white, from one-eight to 

 one-quarter of an inch in diameter. 



The red-purple color is the result of the growth of filaments of the vege- 

 tative portion A (or mycelium) of this fungus, pushing their way between 

 the cells of the interior of the leaf, disorganizing their contents, and absorb- 

 ing their fluids. Air spaces are thus formed in the centre of the spot, giving 

 rise to the dead white appearance which results. In the accompanying cut 



