CHAPTER VIII 

 GOOSEBERRY DISEASES 



COMPARATIVELY few gooseberry diseases are of a serious 

 nature ; they are seldom sufficiently injurious to create anxiety. 

 The American powdery-mildew and the leaf-spot are the most 

 prevalent diseases of this fruit. The gooseberry, like the cur- 

 rant, is affected by the European rust (white pine blister-rust), 

 but is of less importance in this connection than the currant. 



AMERICAN POWDERY-MILDEW 

 Caused by Sphcerotheca mors-uvce (Schw.) B. and C. 



The American gooseberry, mildew is indigenous to the United 

 States, where it is has been known for at least three-quarters 

 of a century. It probably originated in this country on wild 

 gooseberries before this fruit was brought under cultivation. 

 It is believed on good authority that the fungus was carried 

 from the United States to southwestern Russia about 1890, 

 from which point it spread into neighboring European coun- 

 tries. The disease made its first appearance in western Europe 

 in 1900, when it was found in Ireland. Undoubtedly the mildew 

 fungus was introduced from America about that time. In 1 901 

 it broke out again and became increasingly prevalent during 

 the four years succeeding. With Russia and Ireland as centers, 

 the disease soon became prevalent throughout Europe wher- 

 ever gooseberries were cultivated. 



222 



