THE 70 
GARDEN YARD 
soil and the sort of cultivation you give it. All 
these help the crop to withstand disease. On 
the big western wheat fields, it has been found 
that drainage has a most marked effect upon 
blights, wilts and rust. Undrained wheat sec- 
tions suffer greatly from rust. 
Just how diseases are caught by one plant or 
section of a garden from another, is not fully 
known, but we know that insects often carry in- 
fection from one to another, as in fruit trees to 
which bees go for honey. The bee, coming from 
an infected tree to a perfectly healthy tree, may 
bring with it the germs of the disease or the eggs 
of the pest. Many scientific men now hold that 
plant diseases are transmitted by germs, which 
are carried not by insects only but also by the 
wind and the water in the soil. 
The wrong use of fertilizers or barnyard 
manure may often induce disease, simply be- 
cause the unbalanced food supply causes ir- 
regularity in growth, which weakens the plant’s 
resisting power. What is called a “ balanced 
ration,” is of the utmost importance to plants. 
It is not enough that the soil contain an abun- 
dance of some of the elements of plant food, but 
that it contain all of them in nice proportion, so 
that the plant can draw all it needs, and not be 
overfed in some ways and underfed in others. 
