i6o PLANT DISEASES 



Smith, Gard. Chron.^ March 2nd, 1889, p. 2 ; 1889, 

 p. 275, figs. 



Ludwig, Lehrbuch der Jiiederen Kryptogamen, p. 335. 



Oudemans, Verslag Gew. Verd. der IVis-en Nat. Afdeel., 

 1897. 



DOUGLASS FIR BLIGHT . 



{Sderotinia douglassii, Massee. 

 ^=Botrytis douglassii, Tubeuf.) 



Seedlings and young trees of the Douglass fir (Fseudo- 

 tsuga douglassii, Carr.) and Wellingtonia {Sequoia gigantea, 

 Lindl. and Gord.) sometimes have the lead and upper- 

 most shoots destroyed by the Botrytis form of Scleroti?iia 

 douglassii. The same fungus appears to attack Juniperns 

 com7minis. A brownish-grey mould appears on the 

 branches, which soon become curved and finally die, the 

 needles in the meantime falling off. The Botrytis con- 

 tinues to form conidia on the fallen leaves, and minute 

 black sclerotia are formed on the dead branches. Several 

 young plants of Sequoia giga?itea were killed at Kew by 

 this fungus. 



Preventive Means. — If detected at an early stage, 

 spraying at intervals with Bordeaux mixture or potassium 

 sulphide solution would destroy the conidia, and check the 

 spread of the disease. Badly infected trees should be 

 removed and burned. 



Tubeuf, Beitr. z. Kemitniss d. Baumkr., 1888. 



