THE DISPOSAL OF INFECTED SLASH ON TIMBER-SALF 

 AREAS IN THE NORTHWEST 



By Ernest E. Hubert 

 Scientific /Assistant. Forest Pathology, Bureau of Plant Industry 



In discussing the practical relations of forest pathology to forest 

 management, the question is often raised by foresters of the extent 

 to which sporophores of fungi develop on infected slash left upon sale 

 areas following logging operations, and the bearing which this devel:.i- 

 ment has upon the health of the remaining stand. This problem has 

 been given but slight, if any, attention, and its importance in connec- 

 tion with the ever-increasing efforts to improve the health of the 

 forests should not be underestimated. The longevity and spore pro- 

 duction of fruiting bodies developing on slash following the logging 

 operations are the two main factors involved. Since infection of 

 sound trees by a majority of forest tree diseases depends unques- 

 tionably upon the presence or absence of the spores or seeds (in case 

 of mistletoe) producng the infection, it is readily seen that the unre- 

 stricted production of fruiting bodies in the vicinity of susceptible 

 trees will result in the spread of disease and consequent loss of valuable 

 timber. A certain amount of infection is brought about by contact 

 between interlacing roots. This method of infection can not be con- 

 sidered here. 



In order to check the spread of disease and reduce the attendant 

 loss on the sale area and the surrounding stand, some disposition 

 should be made of the infected slash left on the ground following the 

 logging operations, since this infected slash is capable of bearing 

 sporophores of the more harmful fungi, and these act as distributors 

 of the diseases. If proper pathologcal marking ^^ has been applied to 

 the area the slash will consist of a certain number of infected, unmer- 

 chantable trees which were cut and left upon the area to be disposed 

 of along with the brush. The reproduction on the sale areas, and 

 the reserved sound seed trees represent an investment which must be 



Note — Thanks are due Dr. T. R. Weir for helpful suggestions and a part of 

 the data used in this paper. 



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