The Wisconsin tobacco reporter. (Edgerton, Wis.) 1877-1950, 1917-04-06

the tobacco grower has TO contend with
in plant bed management can be cured
by the steamlng process, according to
Prof. James Johnson of the University
of Wisconsin. For damping-off it is a
sure preventative, and the expense of
the process is more than offset by the
cost of the first wedding of beds that
have not been treated. The damping-
off of seedlings is caused by fungus
which attacks the young plant just at
or below the surface of the ground.
Under favorable conditions the disease
will spread rapidly up the stem and in
to the midrib. The characteristic ap-
pearance of seed bed attacked by this
trouble is bending over and whiting
of the diseased plants. The fungus
which causes the trouble has been
identified in several varieties, and rap
idly develops with favorable conditions
of moisture and temperature. The
main results to be accomplished are the
destruction of the fungus, and, second
arily, other diseases and all weed seeds.
The most practical method yet devised
for steam sterilization of seed beeds is
with an inverted pan. "A galvanized
iron pan 6 feet widesby 10 long and 6
inches deep is inverted over the area to
be sterilized, after it has been prepar-
ed for seeding. The edges of the pan
should be sharp enough so that they
can be pressed into the soil an inch or
more and form tight compartment.
Steam is introduced for period of
from 80 to go minutes from boiler at
a pressure of 80 to $50 pounds. The
time of steaming depends largely upon
the type of soil, it's condition and mois-
ture content. Loose, sandy, moist, but
not wet, soil is more easily and rapidly
steamed than heavy and wet soil. The
pan used at the Wisconsin station was
made inches i'll depth, which is more
desirable than inches in some cases.
The pan could be made IL feet in length
without losing any efficiency where
| large boilers are available. The han
dies should be preferably placed on the
sides instead of on the ends, so that
the pan can be moved from one section
to another without the operators walk
ing on the sterilized soil. The weight
of such a pan is approximately 400
pounds. The boiler sho0ld be connect
ed with it by one-inch steam hose.
Steam can be furnished advantageous
ly by traction engine. Weed seeds
nnder the inverted pan system were all
killed at as short an exposure as 25
minutes, starting at 80 pounds pressure
and running down to Is pounds. More
over, the plants in the unsteriliZed
plots were not one-half as large as
those in the sterilized plots one month
after sowing the seed. The cost of one
wedding of the untreated plots was
equal to the cost of steaming an equal
area. This together with an assurance
against bed rot and either pests made
the process economical and we'll worthy
of use on all tobacco farms. The ster-
ilizing of tobacco seed beds by the in
verted pan method can be most cheaply
done by few neighboring farmers in
cooperation, or better still, by per-
son who owns a steam traction engine
who will do the sterilizing by contract
at so much per rod of seed bed.
Encouraged by the high prices paid
for their crops during the past season
and promised for the next few years,
Wisconsin tobacco growers will plant
still larger acreages this spring. There
are many, in fact, who believe that
prices will never again drop to the low
sins tobacco crop is grown principally
in Dane, Rock, Vernon, Crawford, Col
umbia, Monroe, Chippewa, Jefferson,
Richland and Trempealeau counties
These counties each grow 500 acres or
more, the acreage in Dane county
reaching as high as 10000 acres. In
addition, there are a large number of
counties which grow the crop in COM
mercial way but not to the same extent
as the counties named. To aid in cop
ing with certain diseases which are be-
coming increasingly prevalent, num-
Der of experiments in tobacco growing
have been carried on during the past
six years by the Wisconsin experiment
station in cooperation with farmers of
the state, especially those living in
Dane and Rock counties. The results
of these experiments are recorded in a
bulletin recently issued by the Agricul-
tural Experiment Station at Madison
and now ready for distribution to state
residents upon request.