Dakota farmers' leader. (Canton, S.D.) 1890-19??, 1904-08-26
LIFE HISTORY Of RUST FUNGUS.
James F. Bell, Back From The
Wheat Districts, Gives the
Botanical Facts, So Far As
known, About Rust.

Minneapolis Journal: james r
Bell of the Washburn Crosby company
has returned from tour Of the wheat
districts where he made careful study
of the growth and development of rust.
He procured many microscope slides
illustrating the different stages Of
gro with and had several samples of the
" heat and the wheat stalks which had
been attacked. i5s
"Rust we have always with u.s." he
said, while at work in the company'e
chemical laboratory this morning.
ut is always present, but, like the
germs Of disease, requires certain con
ditions to bring about an epidemic.
The damp weather has been ideal fol
a rapid growth of the fungus whose
spores have been lying dormant.
There are several stages in the
growth Of the fungi. They pass from
one to another stage in sort of cir.
cular path and it would be like try
ing to determine which part of a
wheel starts first, to answer what
was the starting point of the presen,
epidemic, Some of the stages are
parasitic and some are not. However,
the progress from one to another is
rapid when conditions favor,
"Let us start with the stage where
the rust is parasitic and has destroyed
the wheat The way the rust attacks
the wheat stalks is simple. It con
sumes the sugar or starch elements
which mature the head thru the saI
and forcing its way to the cuticlt
pierces the epidermis and allows thu
moisture of the wheat to escape
Technically, this is called the develop
ment of It's mycelium in the tissues
The mycelium produces groups o.
single porous sporophores. When thu
rust reaches the surface Of the cpl
dermis, it presents fungus growth of
velvety appearance. Part of the germ
growth on the surface becomes de-
tached thru abstraction and is car
ried to other stalks by the wind.
This second stage is still parasitic
and attacks and destroys the wheat
It is similar to the first stage except
that it works from the outside in. II
enters thru the air poies and developet
it's mycelium. This bears what is
called uredospores. Later, when the
plant becomes hard and dry, the rust
ceases giving off the uredospores and
gives off dark .colored tuluetous spores
which are Of compound character.
THE tuluetous spores remain per
fectly quiescent during the winter sea
son. In the spring they germinate
and either one or both of the cells pro
duce small, free, non parasitic pro
mycelium. In other words, in thii
stage the plant is incapable of attack
ing the wheat But from each of these
cells there is delicate growth. Thif
sporidium is carried by the wind, and
while it does not grow on the wheat
finds a lodgment on certain wild
plants, especially the violet. When thlt
in turn germinates and is carried by
the wind it attacks the wheat. The
growth in the violet is particularly
thick mycelium. This in turn de-
velops into another form which gives
off still another spore, which is scat
tered by the wind again.
while we have found out q good
deal about the history Of the growth
Of the fungus, we are really still ir
the early stages from practical point
Of view. What we have learned il
merely the botanical side. We have
at least determined one thing thru the
recent investigations and that is that
the opinion of Erickson. the Swedish
Investigator. that there are several
different kinds of rust is incorrect
There are different stages in the growth
not different kinds; black rust, RED
rust, all rusts are different develop
ments of the same growth.
"Some wheat has been said to bt
immune, especially macaroni wheat
l have not found it SO. Some OF tht
macaroni wheat was very badly dam
aged. However, it may be said to b'
the least attacked.