Basic HTML Version
Scalingbackscald
FOLIAR DISEASENOMATCH FORNEWLY INTEGRATEDGENETICS
THE FIGHT AGAINST SCALD IS
underway for one of Canada’s premier
feed varieties.
Aaron Beattie, a barley and oat breeder
and the project lead to combat scald resist-
ance at the University of Saskatchewan’s
Crop Development Centre, is leading a
research project that looks to map several
scald-resistant barley genes within CDC
Austenson to develop a variety of barley
with improved scald resistance.
According to SeCan, CDC Austenson
produces grain yields higher than the
other two check varieties, Xena and AC
Metcalfe.
“Austenson has high yield, plump
seeds and good straw strength,” said Jim
Downey, research and development man-
ager at SeCan.
Despite Austenson’s strong leaf-disease
resistance, it lacks adequate protection
against scald, a major foliar disease that
a ects barley in the wetter areas of the
Prairies, especially in Alberta’s southern
parkland region.
“Scald is an important disease to look
at,” Beattie said, adding that the disease
has potential to considerably slash yields.
In fact, scald has cut yields in some fields
by more than 25 per cent. Currently,
average yield losses in Alberta are at 2.4
per cent.
“It’s always been a big issue in parts
of Alberta,” Beattie said. “Depending on
the year, you might see it in southwest
Saskatchewan. However, we saw a lot of it
this year near Saskatoon.”
Scald is found on leaf sheathes and
leaves. Large, water-soaked, grey-green
spots appear on the leaves, which rapidly
dry out and become bleached with brown
spots. Those spots then engulf the entire
leaf and kill it. Subsequently, a decrease
in the photosynthetic area on the flag and
second leaf reduces seed weight, resulting
in yield loss.
If scald appears on the upper leaves
and sheathes in mid-July, farmers should
expect considerable yield loss. If scald
doesn’t appear until early to mid-August,
losses from scald will be considerably
reduced, as grains are well filled by that
time.
To combat the disease, and to ensure
the possibility of higher yields for those
who plan on growing the new breeding
line derived from Austenson, Beattie is
mapping three scald-resistant genes in the
variety.
Beattie is collaborating with Kelly
Turkington, a research scientist with Agri-
culture and Agri-Food Canada (AAFC) in
Lacombe, on this project. Beattie is using
one of Turkington’s nurseries to screen the
Austenson trials.
Each trial, or test, is restricted to the
crop’s lifespan, which is similar to the an-
nual growing season. The data is recorded
each July and breeding lines derived from
Austenson are established and identified.
“We then characterize that data as
to how resistant the barley is to scald,”
Turkington said. He ranks the trials based
on their scald resistance, and sends them
back to Beattie.
“Nothing has surprised me so far,”
Beattie said. “Everything is working out as
we thought it would.”
Even though the implementation of
scald-resistant genes in Austenson will
help defend the crop against scald, Turk-
ington said farmers should rotate crops
and crop varieties every two to three years
to reduce the opportunity for the scald
pathogen population to adapt to the new
breeding lines.
“If you don’t appropriately manage
your field against the scald pathogen
population, new scald-resistant varieties
may no longer be useful for the farmer
and no longer useful for the breeder,” said
Turkington.
Downey echoed concerns with scald’s
presence on the field.
“Scald pathogen populations change
so they can attack certain varieties,” he
explained. “We’ve seen some varieties go
from resistant to poor because of that. It’s
a complex issue.”
But as new disease-resistant lines hit
the market, farmers can expect to use
fewer fungicides, which would e ectively
reduce costs and produce an attractive
crop to sell, said Barley Council of Canada
Chair Brian Otto, who farms in Warner.
“Research like this supports growers’
pocketbooks,” he explained. “It’s good for
our bottom line, and better for the envi-
ronment. We can turn to chemicals, but
I’d much rather invest in a seed breeding
program. Obviously we need both, but the
less fungicides we use, the better.”
The project is slated to finish in 2018.
SCALD SYMPTOMS:
A typical hill plot
of barley with symptoms of scald at the
scald nursery in Lacombe.
Photo: Agriculture andAgri-FoodCanada
Winter
2015
grainswest.com
49