CHAPTER XVII 



DISEASES OF THE GEOSELLES 



The number of fungi known to attack the genus 

 Ribes is very large, yet comparatively few are suffi- 

 ciently destructive to demand consideration from an 

 economic stand -point. The one which is best known, 

 and which has created far more discussion than any 

 other in American horticultural literature, is the goose- 

 berry mildew. This, disease alone, like the phylloxera 

 of the grape, has forced the development of varieties 

 from native species, which doubtless would not have 

 been done had the English varieties proved successful 

 in this climate. The following list includes those 

 diseases which are most important. 



THE MOST IMPORTANT DISEASES 

 GOOSEBERRY MILDEW (Fig. 78) 



Sphceroiheca mors-uvce (Schw.), B. and C. Order Pyrenomycetese. 

 Family Perisporiaeeee. 



Halsted, Rep. U. S. Dept. Agr. 1887:373 (Illus.). Humphrey, Rep. Mass. 

 Exp. Sta. 10 : 240 (1892) (Illus.). Arthur, Rep. N. Y. State Exp. Sta. 

 6: 349. Beach, West. N. Y. Hort. Soc. 37: 512. Close, N. Y. State Exp. 

 Sta. Bull. 133. 



Chiefly found on the English gooseberry, rarely on American 

 sorts. 



As before stated, this is one of the most widely known of the 

 diseases affecting the genus Ribes. It first appears on the young 

 leaves and tender tips of the growing shoots. The young fruits 



BB (433) 



