BODY AND BRANCH DISEASES AND INJURIES 71 



tree surgery, page 345. The necessary care in pruning to leave 

 a wound which will heal most rapidly and protecting the wound 

 in the meantime by the use of wound-dressings are important 

 measiu-es for reducing wood-rots to a minimimi. These opera- 

 tions are also more fully discussed under tree surgery methods. 

 The immediate destruction of newly developing fruiting-bodies 

 of all kinds in the vicinity of tre«s to be protected will reduce 

 greatly the amount of infection, ^f 



In the forest, the factors concerned in the complex of soil, 

 atmospheric and biologic relations, influence greatly the yield 

 and quality of timber that is realized. Methods of forest 

 management in this country have seldom taken into consid- 

 eration many of these vital factors, one of the most important 

 of which is the control of the wood-rotting fungi of living trees. 

 The subject of forest pathology is too complex to be adequately 

 dealt with in a small space and is outside the field of this book. 

 A simple method of disease control in the forest is the elimina- 

 tion of all diseased trees at the time cutting operations are 

 in progress. For some types of forests and systems of selec- 

 tion for cutting, this procedure is not economically possible. 

 Thus it will be possible to control the loss factor due to decay 

 only when all the complex relations existing in the forest have 

 been studied for different types and localities. Before control 

 measures can be incorporated into scientific forest regulation, 

 such points as the following must be determined : the relations 

 which determine the rate of growth and general health of the 

 trees, the extent, nature and cause of wounds, the life history 

 of the wood-rotting fungi, the relative susceptibility of different 

 species and different age classes, and many other relative factors. 



References 



Schrenk, Hermann von. Fungous diseases of forest trees. U. S. Dept. 



AgT. Yearbook 1900 : 199-210, pis. 21-25. 1901. 

 Meinecke, E. P. Forest pathology in forest regulation. U. S. Dept. 



Agr. Bui. 275 : 1-62. 19>6. 



