276 DISEASES OF CULTIVATED PLANTS 



genus Endoconidium disappeared as a conidial condition of a 

 higher form of fungus. A similar fate awaits numerous other 

 genera, accepted as such at the present day. 



It is suggested that -grain grown in a district known to 

 produce the disease should not be used for seed. 



Prillieux and Delacroix, Bull. Soc. Bot. Fr., 38 (1891). 

 Prillieux, Malad. des Plantes Agric., 2, p. 453 (1897). 



Gooseberry collar rot (Sclerotinia juckeliana, De Bary) 

 causes a collar rot of gooseberry bushes frequently met with 

 in this country. The bark just above ground, and also for 

 some distance below, becomes soft, water-logged, and finally 

 turns brown and decays, causing the death of the bush. 

 During the summer months the diseased bark is more or less 

 covered with the Botrytis condition of the fungus, which 

 resembles a greyish mould. When the dead bark is removed 

 numerous irregularly shaped black sclerotia, 3-6 mm. in length, 

 are to be seen embedded in the tissue of the bark. 



Dampness favours the development, as does also the 

 presence of manure or decaying vegetable matter lying on 

 the ground. Deep planting should be avoided. 



Smith, Journ. Bot., Jan. 1903. 



Tobacco rot. Prof. Oudemans has described a disease of 

 tobacco plants caused by Sclerotinia nicotianae (Oudem. and 

 Koning). Diseased plants have limp, slippery leaves and the 

 stem is discoloured here and there. In some cases the dis- 

 coloured spots are more or less covered with a delicate white 

 down, or conidial condition of the fungus, and black sclerotia 

 embedded in the down. The disease is very infectious ; a 

 single diseased leaf mixed with the healthy leaves to the 

 drying shed quickly infects every leaf with which it comes in 

 contact. 



Sclerotia irregular in form, black, up to 10 mm. long, 

 embedded in white mycelium on the stem and leaves, produc- 

 ing up to 20 ascophores ; stem slender, flexuous, 4-6 cm. 

 long; ascophore coniform, then expanding, minute, o - 8 mm. 

 diam. ; like the stem brown, asci cylindrical, 8-spored ; spores 

 elliptical, smooth, hyaline, 5-7 X 3-4 /*. 



Conidial form. Conidiophores ascending from creeping 

 hyphae, crowded, stout, apex tapering and bearing a short 

 chain of globose conidia 2-5 /* diam. 



