356 



Bulletin 163. 



gus have been kept in the laboratory for two 3'ears, and during this 

 time some attempts have been made to secure any other stages that 

 might be connected with the Cescospora, but in culture no fruit- 

 ing forms have been secured. In studies of some other species 

 of Corcospora more or less abnormal conidia* were produced, but 



with this beet 

 fungus not 

 even conidia 

 are developed 

 i n cultures. 

 There is a 

 tendency for 

 the aerial hy- 

 phae to ad- 

 here in clus- 

 ters as they 

 grow out from 

 the substra- 

 tum, as in the 

 upper portion 

 of figure 61, 

 and from 

 these hyphae 

 branches arise 

 as if to bear 



conidia, but none are produced. In the lower portion of figure 61 

 is represented some of the characteristic mycelium which grows 

 immersed, abundant swellings and irregular branching occurring. 

 A close inspection has been made of old diseased leaves during 

 the autumn and winter, but no fungi have yet been found which 

 seem to suggest a perfect stage of this Cercospora. 



c. Kennedies. 

 During the past season the serious injuries due to the leaf spot 

 were not manifest until it was deemed too late to make satis- 

 factory experiments with the use of fungicides for its prevention. 

 For several 3^ears, however, experiments have been conducted by 

 Professor Halsted, at the New Jersey Experiment Station, in the 



60. — Petri dish culture of the Leaf -spot fundus on agar. 



*Compare, Early Blight of Celery, Bulletin 132 of this Station. 



