The Rural Voice, 1986-08, Page 19WHEAT WOES
Looks like the wheat crop yield is down 15 bushels to the acre this year.
by Mervyn Erb
Isuppose it was inevitable, and
deep down we all suspected
that this year, wheat harvest would
not go down as a happy one;
however, we all hoped for the best.
With the dismal present prices
for new crop corn, soys, canola
and barley, I had hoped the 1986
wheat crop would be a bright spot.
The local soft winter wheat
acreage was up to 4 per cent last
fall and reflected the grower's an-
ticipation of inevitable poor corn
and soy prices for fall 1986 and the
desire for some early cash flow
during the summer of '86.
Also, fresh in the grower's mind
was the record yields of 1985. So it
was gung-ho into wheat last fall.
The crop went in timely and
emerged well.
The many acres we custom ap-
plied and air seeded with our Lor-
al looked exceptionally well,
reflecting that many of you fellows
have the recipe for incorporation
and seed -to -soil contact down pat.
However, it was not to be.
Something looked wrong by
November 4.
You get to cover a lot of ground
when you hunt with Dean Aldwin-
ckles' crew, and when you're put
on a stand you stay there and sit
quiet. That's when I noticed it —
off -coloured wheat, pale areas,
especially those areas of drill
overlaps on headlands and
overlaps going down the field, as
well as custom application
overlaps. Those areas had a high
incidence of small accumulations
of powdery mildew. Many fields
were showing areas of stressed,
off-colour wheat.
Then along came February.
Areas of heavy snow build-up
smothered out and/or caught snow
mold. The February thaw, rain,
freeze, thaw, freeze scenario took
out many of the low areas of
fields. Before we knew it, along
came an early spring and the wheat
was off and running, and it looked
good. Spring nitrogen applications
were timely, almost all of it done
on dry, firm fields.
Then it struck. The cool, dry
weather of April and May — and
with it came powdery mildew.
Powdery mildew development is
optimal between 15 and 22°C.
Wheat is most susceptible during
periods of rapid growth. Dense
stands of susceptible varieties,
heavy nitrogen fertilization, high
humidity and cool temperatures
favour disease development. The
cleistothecium (or the brown -black
dots in the fuzzy mildew) develop
as temperatures increase or as the
fungus and the wheat mature or
become moisture -stressed. The
resultant conidia are wind -
dispersed and induce secondary in-
fections. In favourable field en-
vironments, germination, infection
and secondary sporulation are
completed within seven to 10 days.
This parasitic fungi utilizes the
nutrients, reduces the photosyn-
thesis and increases the respiration
and transpiration of the wheat.
Infected plants lose vigour and
their growth, heading, and seed
filling are impaired. Yield losses
occur in relation to the intensity of
attack and are measurable as
reduced head numbers and kernal
weights. Losses are greatest when
plants are infected as seedlings and
disease development continues
through flowering.
To add up yet another deluge of
dollar devastating destruction,
came the Septoria Complex, not to
be confused with the Stanley Com-
plex at Varna. The Septoria Com-
plex comprises septoria leaf spot
and septoria glume blotch. (The
glume is the shell or chaff that en-
cases the wheat seed).
This parasitic fungal disease has
become worse as we've selected
more rust -resistant wheat varieties.
Symptoms develop throughout the
growing season, starting with the
lower leaves first, especially those
touching the ground. The destruc-
tion of leaf tissue is certainly hard
on the plant's factory. Seed set is
not adversely affected, but seed
filling is impaired and shrivelled
grain is lost with the chaff at
harvest.
Then on June 28, we en-
countered the armyworm. Inconse-
quential for most, but a source of
aggravation, yield loss, and more
expense, for those whose infesta-
tion was severe enough to warrant
spraying.
Also along this same time, we
began to notice Fusarium head
blight (may also be known as scab,
pink mold, white head or, tomb-
stone scab). It is best recognized on
emerged, immature heads where
one or more spikelets or the entire
head appears prematurely bleach-
ed. In some cases, these bleached
heads were the result of
"Take -all" root disease, however
the majority was Fusarium head
blight. Significant yield losses
result from floret sterility and poor
seed filling.
But here comes the clincher.
Grain from the head -blighted
fields is found less palatable by
livestock and sometimes contains
sufficient mycotoxins to induce
muscle spasms and vomiting in
man and certain other non-
ruminant animals, (hogs).
The toxins apparently remain
stable for years in stored grain.
As well, to make matters all the
more confusing, an infrequent and
inconsequential disease called
"pink seed" (caused by a
bacterium this time, not a fungus),
has been spotted. Diseased seeds
are normal looking but have soft,
pink endosperms. They often
resemble the colour of treated
seed, but only pink on the en-
dosperm, not the whole seed. This
little ditty is bound to create mass
confusion in most probe rooms
around the countryside, trying to
tell the harmful diseases from the
not -so -harmful ores.
And then to add injury to insult,
we had the extremely hot and
humid weather from July 16 to 19.
Reports of sprouted wheat,
mycotoxins, wheat not fit for mill-
ing, and wheat not even fit for feed
are rampant today as I write this
(July 22).
Tonight, as I drove home from
work, 1 counted five combines at
work, so by the time you read this,
this year's wheat harvest will be
just about history and hindsight
will be 20/20.
With so many things going
against the wheat crop this year in
this area, the crop may be down
approximately 15 bushels per acre.
Now if you're really masoch-
istic, (that's a 50 cent word for
"the abnormal getting of pleasure
from inflicting pain on one's self")
try growing hard red wheat.
AUGUST 1986 17