270 Strawberry-Growing 



The usual rate of application is three or four pounds to 

 fifty gallons of spray; in most cases it is put into the 

 bordeaux. Paste lead should be mixed with a little 

 water to make it liquid before it is added to the bordeaux. 

 Powdered arsenate of lead is equally effective if used at the 

 rate of one and a half to two pounds for each fifty gallons 

 of spray. 



It is not safe to spray a fruiting field after the blossoms 

 open ; the spray will injure the blossoms and mark the 

 berries. Leaf -eating insects that appear between blossom- 

 ing and harvesting may be controlled with fresh powdered 

 hellebore at the rate of one ounce to two gallons. 



Xurser\Tnen located in districts that are infested with 

 root-louse should fumigate their plants with hydro-cyanic 

 acid gas before they are shipped. 



PLANT DISEASES AND THEIR CONTROL 



Leaf-spot, rust or leaf-blight (SphcBrella fragaricB). 



This is the most common and most conspicuous disease attacking 

 the strawberry. It occurs on nearly all cultivated varieties to some 

 extent, and on the \\-ild strawberry, F. mrginiana. The leaves are 

 covered ^^^th small spots or blotches, which are reddish or purplish 

 at first ; later the center becomes ashy white, bordered with red 

 or purple (Fig. 17). The spots are distributed irregularly; when 

 numerous they run together, forming irregular blotches. The 

 healthy leaf surface is so reduced that the fruit does not develop 

 properly and few runners form. Sometimes the disease attacks the 

 fruit-stems and cuts off the food supply of the berries so that they 

 shrivel when half growTi. In very severe attacks, the whole bed is 

 practically ruined ; by midsummer it looks as though scorched by 

 fire. Plants in heavy, wet soil are more likely to be affected than 

 plants on light, dry soil. 



Bordeaux lessens the severity of the attack, but does not hold the 

 disease in check altogether. Spray the fruiting bed twice before 

 the blossoms open and again immediately after; a field of virgin 



