The Rural Voice, 1980-09, Page 36It's planting
time
—for winter
wheat
Planting time is just around the
corner for the southwestern Ontario
growers who produce more than 60 per
cent of the province's winter wheat.
To help producers make the most of
this valuable crop, used primarily for
pastry flour, Arend Smid of the
agronomy section at the Ridgetown
College of Agricultural Technology
offers these tips.
First, plant on time. For south-
western Ontario, seeding dates are
September 25 to October 10. Seeding
after the recommended dates increases
the risk of winterkill, reduced yield, and
lower test weights at the mill.
"If farmers have to plant after
October 10, because of late harvest of
soybeans, they should plant the Fred-
rick variety instead of Yorkstar," says
Dr. Smid. "Yorkstar tends to drop
quickly in weight when it is seeded late,
and low test weights result in docked
prices at the mill."
Dr. Smid also stresses the importance
of crop rotation for winter wheat.
Although some producers plant winter
wheat in the same fields in successive
years, this practice is not recommended
because of the build-up of soil -borne
diseases.
"There haven't been too many prob-
lems in the past few years," says Dr.
Smid. "However, last year the presence
of several root -rot organisms increased
dramatically. In some fields, where
moisture and weather conditions were
favorable for the diseases, yields were
reduced from 60 bushels per acre to
only 15."
Producers should also take note of the
recent changes in seeding rates. Two
years ago, the recommended seeding
rate was increased from 100 kilograms
per hectare (1.5 bushels per acre) to 130
kg per ha (2 bu/A). In RCAT tests, the
higher seeding rate increased yields by
150 kg per ha (2.2 bu/A). This higher
seeding rate is crucial for Tate -seeded
fields, to encourage the plants to
spread.
Some data show that broadcasting a
seed/fertilizer mix, followed by light
tillage, can be as effective as drilling the
seed. However, this seeding method is
not recommended unless the grower
can ensure even distribution of seed,
Dr. Smid says.
MAILBOX
OF THE
MONTH
belongs to:
Nick and Kay Lang
Carrick Township,
Bruce County
U of G makes progress
on bovine tumours
An antigen produced by a research
tream at the University of Guelph
working under Prof. V.E.O. Valli,
chairman of the Department of Path-
ology, has permitted scientists to detect
inapparent tumors by natural immune
mechanisms.
Prof. Valli and his team have been
investigating bovine lymphoma, a virus -
induced disease that affects about
two-thirds of dairy cattle in Canada and,
in a small number of cases, leaves the
infected animal with a malignant tumor.
By injecting the antigen into cattle
and watching the animals' reaction to it
scientists can tell if the animals are
carrying the tumor. Before this tech-
nique was developed, they had to
remove cells and study them, which in
any case only indicated whether the
animal had viral infection, not whether
or not it had the tumor, says Prof. Valli.
Now, Prof. Valli continues, "we want
to see if we can take this material (the
tumor antigen) and use it as a vaccine to
prevent tumor formation. If it works, it
will have tremendous implications." It
could be given to calves to protect them
at birth, before they become infected.
The University of Guelph has also
been co-operating with other agencies
in a number of cancer -related projects.
Since bovine lymphoma is similar to
human lymphoma, a comparative study
has been undertaken with the Ontario
Cancer Institute at Henderson Hospital,
Hamilton, to see if the bovine virus is
significant in causing human cancer.
Findings so far indicate it is not.
Plastic sleeves
help pesticide research
The effects of pesticides on aquatic
life in a lake are being studied by a
group of researchers at the University of
Guelph using an unusual study tech-
nique.
Large plastic sleeves called limno-
corrals permit the researchers to isolate
a section of lake water and examine
what happens when controlled amounts
of various materials are added to the
water. The limnocorrals resemble an
inflated rubber ring about five meters
by five meters mounted on a wooden
frame, and with plastic curtains that
extend to the bottom of the lake where
they are embedded in the mud.
The multi -disciplinary team of Uni-
versity of Guelph researchers are
assessing the effect of pesticides on
predator/prey (food species) balance
using Lake St. George, a restricted area
owned by the Metro Toronto and Region
Conservation Authority.
They hope to develop a method for
future evaluation of any pesticide that
may find its way into a body of fresh
water.
Some limnocorrals are left untreated
as controls while others receive differ-
ent concentrations of the pesticide
under study. Test materials are applied
with a special multi -orifice injector to
ensure even distribution and to mini-
mize disturbance of sediment.
Water samples permit the research-
ers to identify major groups of organ-
isms present and to assess effects and
recovery over a period of time, as well
as the rate of disappearance of the
material.
Professor Narinder Kaushik, an
aquatic biologist, saw limnocorrals in
use elsewhere for studying industrial
pollutants in lakes, and adapted the
technique for studies of pesticides. In
this way, he explains, effects on the
ecosystem can be studied without
contaminating or endangering an entire
lake.
The University of Guelph research
team is examining a number of insect-
icides and herbicides used in agricul-
ture and forestry at the Lake St. George
location.
THE RURAL VOICE/SEPTEMBER 1980 PG. 35