424 MANUAL OF FRUIT DISEASES 



spores may be found therein. Unlike the ascospores of most 

 ascomycetous fungi, they are not ejected from the perithecia 

 nor are they blown to the new leaves. They germinate within 

 the perithecia, even while yet in the asci, their germtubes 

 emerging both through the ostiola and through breaks in 

 the walls of the perithecia. At these points the germtubes 

 cease growth and form conidia which are cut off and carried 

 to the strawberry and cinquefoil. The first infections of the year 

 occur most commonly about the time the fruit sets; later 

 ones develop throughout the growing-season. The conidia 

 germinate in the presence of moisture, and the tubes penetrate 

 the plant more commonly through the cuticle, rarely through 

 the stomata. 



It has been shown that the mycelium does not descend to 

 the roots or stems to hibernate. But, recapitulating, the winter 

 is spent as follows : (1) as mycelium in the leaves ; (2) as sclero- 

 tial bodies on the surfaces of the leaves; (3) as immature 

 perithecia in the leaves. 



Control. 



In selecting varieties for planting, avoid the more susceptible 

 sorts. Set in well-drained soil, and use only healthy plants. 

 Remove diseased leaves before setting. Spray with bordeaux 

 mixture 4^4-50 before the blossoms open to protect the plants 

 against first infections. Repeat the application two or three 

 times as the occasion demands. In ordinary cases, the first 

 spraying is done just after the fruit is harvested. If there is 

 an unusual prevalence of leaf-spot, renew the settings annually. 

 Mowing and burning after harvest will often given a new set 

 of leaves which go into the winter quite free from the fungus. 



REFERENCES 



Scribner, F. L. Strawberry leaf blight. U. S. Agr. Comm. Kept. 



1887:334-341. 1888. 

 Dudley, W. R. On the strawberry leaf-blight. Cornell Univ. Agr. 



Exp. Sta. Bui. 14 : 171-182. 1889, 



