CHAPTER XVIII. 



TREE DISEASES AND THEIR TREATMENT 



IT is not possible that every tree planter should possess 

 the technical knowledge required for the precise diag- 

 nosis of every tree ailment, for this is to be gained only by 

 special technical training and practice. The individual, 

 however, may at least familiarize himself with some of 

 the fundamentals. An effort is here made to furnish help 

 along this line. 



Fungus growths on plants are of two kinds. One type 

 known as the parasite lives upon wood bark, leaves or 

 other live parts and takes its nourishment at the expense 

 of the tree's vitality. In thus feeding it robs the tree of 

 its strength and vigor and brings about serious damage. 

 The other type known as the saprophyte lives upon 

 dead plant material. With this distinction in mind it will 

 be clear that, with respect to fungous diseases, the par- 

 asite is cause and the saprophyte effect. 



Fungi attack all parts of the tree, from roots to foliage, 

 flowers and fruit. The results are of varying character and 

 manifest themselves in various ways. Frequently, the 

 location of the chief damage is altogether remote from the 

 point of attack, since a disease of the roots will often 

 manifest itself through dying leaves and branches at the 

 top of the tree. The most common form of damage, how- 

 ever, is localized and brings about the death of individual 

 leaves or branches or causes decayed cavities which prove 

 fatal if allowed to progress. 



A fungus starts from spores, or tiny organic dust-like 



particles, corresponding to seeds in purpose, which are 

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