146 



TREES IN WINTER 



CHAPTER IX 

 THE CONTEOL OF PARASITES. 



FUNGUS TROUBLES. 

 Trees are subject to a great many kinds of disease. Few diseases, 

 however, are so serious as to require treatment. Tree diseases are 

 caused mostly by parasitic fungi, which are low forms of vegetable 

 life that live upon and within the tissue of the host plants. The 

 most serious forms, from the shade-tree standpoint, are those caus- 

 ing the decay of the trunk and main branches. Since such forms 

 are not capable of entering the uninjured bark these troubles usually 



Fig-. 71. A Red Oak tree injured 

 at the base by fire. A fungus gained 

 access through the wound and is 

 rapidly rotting the sapwood beneath. 



may be prevented by taking proper care of the wounds. It should 

 not be assumed that the mere removal of the toadstool-like growths 



