The Minneapolis journal. [volume] (Minneapolis, Minn.) 1888-1939, 1904-08-20
CITY NE VS.
LIFE HISTORY
OF RUST FUNGUS
BLACK AND RED DIFFERENT
STAGES OF SAME GROWTH.
James #. Bell, Back from the Wheat
Districts, Gives the Botanical Facts,
So Far as known, About Rust.

James r. Bell of the Washburn-
Crosby company, has returned from
q tour of the wheat districts where he
made careful study Of the growth
and development of rust. He pro-
cured many microscope slides illus
trating the different stages of growth
and had several samples Of the wheat
and the wheat stalks which had been
attacked.
Rust we have always with u.s. he
said, while at work in the company's
chemical laboratory this morning.
TT is always present, but, like the
germs of disease, requires certain con-
ditions to bring about an epidemic.
The damp weather has been ideal for
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
wheel started first, to answer what
was the starting point Of the present
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. 1t con-
| sumes the sugar or starch elements
! which mature the head thru the sap
and forcing it's way to the cut1cle
/ pierces the epidermis and allows the
moisture of the wheat to escape.
Technically, this is called the develop
ment Of it's mycelium in the tissues.
The mycelium produces groups OF
single porous sporophores. When the
rust reaches the surface OF the cpl
dermis, it presents a fungus growth OF
velvety appearance. Part OF the germ
|
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
its 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.
1.-THE tuluetous spores remain per
fectly quiescent during the winter sea
son. In the spring they terminate
and either one or both of the cells pro-
. duce a small, free, non-paraslt1c pro
mycelium. In other words, In this
stage the plant is incapable Of attack
ing the wheat. But from each OF tnese
5 cells there is delicate growth Th1:
sporidium is carried by the wind, ant
l while it does not grow on the wheat
finds a Judgment on certain W1lt
: plants, especially the violet. When Thu
. in turn terminates and is carried b!
2 the wind it attacks the wheat. Th'
I growth in the violet is a particular.
Q thick mycelium. This in turn de
9 velops into another form which give
4 off still another sspore, which is scat
: tered by the wind again.
l while we have found out goo
: deal about the history of the growtl
of the fungus, we are really still Il
. the early stages from a practical poin
. of view. What we have learned
:. merely the botanical side. We hav
= at least determined one thing thr
! the recent Investigations and that
~ that the opinion Of Erickson, tn
;. Swedish investigator that there ar
r. several different kinds Of rust is in
# correct. There are different stages i
o the growth, not different kinds; blac
8 rust, red rust, all rusts are differer
If developments of the same growth.
Is Some wheat has been said to
n immune, especially macaroni whea
Le I have not found it SO. Some Of tn
$. macaroni wheat was very badly dam
a aged. However, it may be said to b
,r the least attacked"