CHAPTER XVIII. 
TREE DISEASES AND THEIR TREATMENT 
I T 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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