J-91G] PARASITIC RlllZOCTOXlAS IX AMERICA 335 



TOBACCO, Nicotiana sp. 



In 1904 Clinton 14 noticed a seed-bed rot of tobacco, which he 

 thought was due to Rhizoctonia. The same year Selby 105 observed a 

 similar bed rot of tobacco in Ohio caused by Rhizoctonia. He stated 

 that the specific characteristics of the fungus do not differ essentially 

 from those of its forms on other plants, including potato. 



Clinton, 15 in making another report on this disease, in 1906, stated 

 that the injury to the plants was slight and was confined, as with the 

 potato, to the underground parts. 



Johnson 63 has carried on some extensive work on Rhizoctonia, with 

 a view to controlling the damping-off of tobacco seedlings. 



TOMATO, Lycopersicum esculentum 



A damping-off disease of tomatoes caused by Rhizoctonia has been 

 noted from a number of states ; the symptoms of the disease are the 

 same as have been described for a number of other plants, such as 

 eggplant. 



In connection with his work on the potato rosette resulting from 

 Rhizoctonia, Selby 104 also mentioned a tomato rosette caused by the 

 same fungus. He stated that the tips of diseased plants showed 

 rather long internodes and dwarfed leaves, with somewhat curled-leaf 

 aspects, while the roots had lesions and other similar features found 

 in potato rosette. 



Rolfs 95 in 1905 stated that he frequently found the Corticium stage 

 on the tomato plant, but that apparently the plants do not suffer ma- 

 terially from its presence when planted on well-aerated land. He 

 described it as follows : 



"The fruiting stage of the fungus develops freely on the stem just above the 

 surface of the ground, often extending up the stem for a distance of six inches. 

 As a rule the fungus does not penetrate the tissue here, but simply covers the stem 

 of the plant. The tomatoes which touch the ground are frequently more or less 

 covered by a fruiting membrane of the fungus, which mars the appearance of the 

 ripe fruit. So long as the tomatoes are green and the skin uninjured, the fruit 

 remains sound; however, if the skin is ruptured, the fungus soon destroys it, pro- 

 ducing a brown rot. This organism also frequently gains entrance to the fruit at 

 the stem end. ' ' 



Orton 72 described the rosette of tomato caused by Corticium vagum 

 B. & C. as a disease of minor importance in tomato culture. He stated 

 that ' ' the fungus attacks the roots and base of the stem, forming dark 

 cankers. The effect on the plant is to dwarf and curl the leaves and 

 to restrict productiveness." 



A fruit rot of the tomato has also been observed by Pool 86 and 

 again by Wolf. 141 Pool described the symptoms of the fruit rot as 

 follows : 



"The specimen examined showed no rupture in the external skin visible to 

 the naked eye. The diseased area was plainly distinguishable by the chocolate- 



