The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1894-03-11
FUNGOus DISEASES.


Atmsiy Spraying.
Charles V. Piper.
Fungous diseases of plants annually
cause tho loss OF many millions of dollars
to the farmers Of the United States.
Within the past six years il has been
abundantly demonstrated that much of
this loss can be prevented by certain
chemical fungicides at so small a
cost ~ TO leave the farmer a
handsome additional profit. While
the losses from these diseases in this state
have not been very serious. they have been
severe enough to demand earnest atten-
ton. Thus far, either from q mistaken
idea Of the amount of damage really done
or from ignorance regarding methods of
treatment, none Of these diseases, with
the exception OF the grain smuts, have
received any attention whatever from
the farmers OF this state. The purpose of
this bulletin Is to describe in brief and
popular way the more common diseases of
this character which occur in the state and
the methods Of treating them which have
proved most successful.
All furgous diseases are caused by
minute, lowly organized plants called
fungi. Fungi are plants in every sense Of
the word. For instance, the fungus caus-
ing the ''black knot" of the plum is just
as much . plant a. the plum tree
itself, though immensely lower in
the scale Of nature. Fungi are en-
tirely destitute of tho green color
ing matter. chlorophyl. which most
plants possess, and upon which their
power to change inorganic matter into
vegetable tissue depends. Therefore fungi
l,va ,oft A.
or dead. which has already been
elaborated by other plants or
animals. Depending on whether
fungi obtain their nourishment from
dead or from living matter, they may be
divided into two groups. namely, those
which live on dead matter. or saprophytes,
such as mushrooms. moulds, etc, and
those which exist on living plants. or
parasites. 1t Is the latter class. the paras-
itic fungi, that cause most plant diseases,
and with which We have to deal.
The vegctative body of these fungi con-
sists entirely Of very minute, transparent
threads, termed hypAr. which ramify over
the surface Of or between the cells of their
host plants, robbing them OF their juices
mainly by minute sucking organs.
This continual drain on the resources of
the host seriously impairs its vitality, and
frequently causes the death OF the tissue
attached. or distortions; In other cases the
whole plant succumbs to the attack OF the
fungus.
All fungi reproduce themselves by bodies
called spores. which for all practical pur.
poses answer to the seeds Of higher plants;
most species produce two, or even more,
kinds OF spores at different seasons. Those
earliest formed are called summer spores,
or conidia. and by their vast numbers and
extreme lightness serve to spread the fun
gus very rapidly; other spores. called rest
ing spores, are more complex IN character.
and tide the life OF the fungus through the
winter.
In many cases the weather has marked
effect on the appearance and abundance of
fungoas diseases. but IL Is In no case the
cause OF sny OF these diseases, as still 80
commonly supposed. Just as certain con-
dltions of moisture and temperature are
favorable 10 all plant life. so they are 10
fungi, only in the case of tae latter the
effect is much more marked.
IL has been found that IN the presence OF
certain chemicals, notably the copper
salts, that spores will not terminate, and
it is upon this fact that the efficacy of tho
fungicidcs rests. ft must be borne in
mind that fungieldes are prevenfiyes only;
not cures in any sense of the word. IL Is
equally out of the question TO ins.iii life
into tissue killed BY fungi. or to
tissue without injuring the host "a
we'll; all We can do is to prevent
the plant tissue from becoming diseased or
killed by preventing the termination and
growth OF the spores. and this is accom-
piished by keeping the plants covered with
fungicides until danger OF attack 10 over.
IL il Q very common mistake TO delay ap-
plying fnngicides until some sign of the
disease Is visible. The mere fac, that the
disease IL visible shows that damage has
already been done. which the earlier APP
plication would nave prevented.