14/03/05
Delayed
growth will make late spring and early summer brome control in
winter wheat particularly important this season, warns Agrovista
technical manager, Mark Hemmant. Especially so, following the
upsurge in problems experienced with the damaging weed by so
many growers last year.
"Recent experience has, thankfully, taught us that brome
can be very effectively controlled well into May and through
to wheat GS39 with the right strategy," he points out. "But
growers will need to plan ahead carefully, not least to ensure
they leave space in their programmes for the specialist sulfonylurea
treatments required.
"Pre-emergence flufenacet +pendimethalin (Trooper / Crystal)
did a good job on brome where it was used correctly last autumn.
With persistent wet weather disrupting many spraying programmes
and the cold February and early March delaying spring growth,
though, there are plenty of post-em grass weed herbicides still
to go onto the wheat crop. And they could easily compromise brome
control if not planned correctly.
"For instance, Atlantis (mesosulfuron + iodosulfuron) will
be an important component for many," he notes. "However,
no-one should rely on it for brome control. Equally, because
it's an SU, sequence restrictions will prevent either of the
available brome herbicides being used in the same programme."
Where brome is the major problem, Mark Hemmant insists that
growers must leave space for either Monitor (sulfosulfuron) or
Attribut (propoxycarbazone-sodium) in their spring programmes
by avoiding sulfonyureas to control other weeds. Instead, he
suggests using mixtures like Hawk (clodinafop-propargyl + trifluralin)
+ IPU. While single brome herbicide applications will be fine
to tackle meadow, soft, rye and even great brome, he stresses
that split dose regimes of the same product are best to tackle
sterile brome, pointing out that where the second split is not
applied 3-4 weeks after the first results will be very disappointing.
He always recommends using an appropriate adjuvant such as Galion.
"It's important to appreciate that Attribut has a GS32
label latest timing restriction this season," explains Mark
Hemmant. "So in a late season like this where crops may
move through the growth stages very rapidly once the weather
warms-up, Monitor (which is safe up to GS39) will give a wider
window for that all-important second split.
"The choice between the two brome herbicides really depends
on your following crop requirements, though. If you want to grow
oilseed rape after your wheat, you'll have to use Monitor.
"Monitor scores too where the greatest tank-mixing flexibility
is important and where good cleavers control is a priority. On
the other hand, Attribut is better where black-grass is mixed
in with the brome.
"Whatever your approach with brome this spring, it's important
to get it right," he concludes. "Time may not be on
your side.
"So, keep a close eye out for the weed this spring. Avoid
SUs to control other weeds wherever brome is a particular problem.
And, make sure you apply the recommended single or split brome
herbicide regimes correctly.
"Fail to do so, and as many people found to their cost
last year, you're likely to be facing serious yield losses and
particular harvesting difficulties."
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