DISEASES IN GREENHOUSE 99 



though the same fungus is recorded on 

 other hosts. During the winters of 1911 

 and 1912, it was found by the author on 

 greenhouse sweet peas from different lo- 

 calities. Through correspondence, Pro- 

 fessor A. D. Selby reports its presence in 

 Ohio; Dr. W- G. Sackett, in Colorado; and 

 Professor E. C. Stackman, in Minnesota. 

 There seems no doubt that the Rhizoctonia 

 root' rot of sweet peas is much more wide- 

 spread than is reported. The nature of 

 the trouble is unknown to the growers. 

 Outdoors, Rhizoctonia also attacks the gar- 

 den pea, bean, lettuce, carrot, celery, cow 

 peas, and a number of other hosts. 



Symptoms. Severely infected plants 

 have practically no root system (fig. 5). 

 In slightly infected plants, only one or two 

 rootlets may b'e destroyed. The fungus 

 produces a browning eifect of the root be- 

 fore total destruction sets in. In very 



