Features Agronomy Cereals
Volunteer barley more competitive than wild oats in wheat

New research is showing just how competitive and costly volunteer barley can
be in a wheat crop. "A single volunteer barley plant per square metre can
reduce yield by 1.9 percent," says John O'Donovan, a research scientist
with Agriculture and Agri-Food Canada's grains and oilseeds team. "That
compares to our previous work with wild oats that shows a single wild oats plant
reduces yield by 0.7 percent." (See Figure 1).

Extrapolate that yield loss to a quarter-section and the ultimate result is
a substantial reduction in what ends up in the grower's pocket after harvest.

The research into the impact of volunteer barley has been conducted at six
locations in Alberta, Saskatchewan and Manitoba over the past two growing seasons,
using herbicide tolerant Clearfield hard red spring wheat. Although data from
2004 is still being compiled, early reports indicate that results will be quite
similar to last year's.

"Volunteer barley tends to be much more competitive than wild oats,"
says O'Donovan, who is world renowned for his work on yield loss/weed competition.

The recent launch of Clearfield wheat in western Canada gives growers another
tool, in addition to crop rotation, to control volunteer barley. The first Clearfield
wheat variety, CDC Imagine, is now on the market and was developed using traditional
plant breeding methods to be tolerant to Adrenalin herbicide from BASF.

"Prior to the development of this new technology there was no product
to control volunteer barley in wheat," O'Donovan says, explaining why this
research has not been done before.

John McCulloch, marketing manager for Clearfield and cereal crops with BASF,
explains that other products on the market control wild oats, green foxtail
and other grassy weeds, but Adrenalin goes beyond that to control volunteer
barley as well as off-types of wheat.

Rotation strategies, like not planting wheat after barley, have helped growers
control volunteer barley in the past, but McCulloch points out there can still
be significant amounts of volunteers two to three years after a barley crop.

For this reason, the rotation solution is far from ideal because volunteer
barley not only reduce yield, it can also lead to a grade reduction. Barley
dockage of more than 2.4 percent will reduce the crop to feed grade McCulloch
notes, which hits growers where it hurts with a substantially lower price. Top
quality – Grade One – wheat can only contain up to 0.6 percent foreign
material, such as volunteer barley.

Off-types of wheat can also be a problem. Number One Hard Canadian Western
Red Spring only allows for 0.75 percent of another class in the sample. McCulloch
adds that BASF research to-date indicates that as few as six plants per square
metre can cause up to a five percent yield reduction.

To avoid penalty when selling crops, blending on-farm or at the elevator may
occur. Clearfield wheat with Adrenalin herbicide can eliminate this hassle,
McCulloch says. "The Clearfield wheat production system removes volunteer
barley from the crop, which increases yield and lowers dockage."

McCulloch is quick to point out that Adrenalin herbicide controls more than
volunteer barley and off-types of wheat, barnyard grass, Persian darnel and
green and yellow foxtail are all on the label. In addition, Adrenalin will control
Group 1 resistant wild oats and millet.

"With Clearfield wheat and Adrenalin, growers now have complete grass
control in wheat for the first time as well as broadleaf control, all in one
pass," McCulloch says. Altogether it controls 40 broadleaf weeds and suppresses
24 more.

"Adrenalin is definitely a resistance management tool," McCulloch
adds. With more than 80 percent of wheat acres treated with Group 1 products,
Adrenalin's dual mode of action (Group 2 and Group 4 chemistry) has an important
role to play.

McCulloch is optimistic that the new Clearfield wheat system may persuade some
growers that have given up on barley to give it another try.

Brian McIntyre, owner of Charann Farms in Neilburg, Saskatchewan, 60 kilometres
south of Lloydminster, is one grower already sold on the new system. He farms
700 acres and grew 90 acres of Clearfield wheat in 2004. He plans to increase
his Clearfield wheat acreage to about 160 acres in 2005.

"We grew it on barley stubble purposely to see how it would control volunteer
barley," he says. "It did an excellent job. It was very difficult
to find any volunteer barley at all." Weeds of greatest concern in his
area other than volunteer barley include wild oats, wild buckwheat, cleavers,
pigweed, stinkweed, hempnettle, foxtail and narrow-leaved hawk's beard. He did
a pre-seed burndown before planting the Clearfield wheat.

"My weed control was excellent," McIntyre comments. "That kind
of control with volunteer barley gives you another option in your crop rotation."

Even more important, yield was equivalent to other wheat varieties that he
grew, about 45 bushels per acre. McIntyre straight cut his crop and felt that
the Clearfield wheat stood up a little better than the other varieties. In a
tough year with early frost, he was particularly pleased to find an alternate
market for his entire wheat crop, including the Clearfield variety, which netted
him about 40 cents extra per bushel.

Clearfield wheat is internationally recognized as non-genetically engineered,
therefore there are no barriers to world markets.

While McIntyre has seen the value of the Clearfield system for wheat first
hand, all growers have not yet had that opportunity. "We had a limited
amount of seed in 2004. Availability will be greater for 2005," McCulloch
says.

McIntyre does not hesitate to tell other growers to give it a try. "I
was satisfied with yield and protein and very satisfied with the volunteer barley
control," he says to sum up his experience. -30-