18 BULLETIN 191 



but in -so doing often remove branches which still are partly green 

 and in which the protective layer of resinous wood has not formed. 



2. Removal of fruiting bodies. If fruiting bodies are removed 

 and destroyed and a disinfectant is applied to their former sites on the 

 trees much good will be accomplished. This may be done according 

 to Moller (5) by a crew of two or three men equipped with ladders 

 with instruments for hewing out the sporophores and with some 

 form of disinfectant to apply to the spots where the fruiting bodies 

 were located. Caterpillar tar (Raupenleim) is the disinfectant com- 

 monly used in this work. Its application in this manner is known to 

 have prevented the formation of new fruiting bodies in at least 80 

 percent of the cases where it was used. Kienitz (8) states that it costs 

 about 10 cents an acre to do this work. 



3. The cleaning out of infected trees. Infected trees can be 

 recovered thoroughly only by a careful survey of the tracts by a man 

 who is trained in detecting the disease. The complete removal of the 

 whole tree is necessary because of the chances of further infection, 

 either from the mycelium or from fruiting bodies on the fallen trees. 

 This operation should not be expensive, as enough of the lumber cut 

 would be worth saving to pay for the cutting. This cutting could be 

 made best in the form of a thinning. Hollrung (7) advises a complete 

 inspection and cleaning of an infected forest every five years in order 

 to maintain complete control of the disease. 



Obviously all these methods are radical and are applicable in their 

 entirety only where intensive forestry can be practiced. The problem of 

 prevention in this country assumes a different aspect because lumber 

 prices do not permit as intensive methods as obtain in Europe and 

 because the sporophores apparently do not grow as abundantly, in the 

 Northern states at least, as they do in Germany. 



In view of the fact that evidence points toward the probability 

 that fruiting bodies may form and function on dead trees, it appears 

 that the first procedure should be to remove carefully all dead and dis- 

 eased wood so that it will not spread the disease. Then, secondly, over- 

 thick plantations should be thinned. 



The writer noted a significant fact in his study of Vermont forest 

 conditions in their relation to red rot, namely, that the disease was 

 much more prevalent in stands in need of thinning and of an improve- 

 ment of silvicultural conditions than in well-handled stands. Proper 

 thinnings should be made, if possible, in rotation. Thinnings thus 



