vegetables

12
WEEDS ARE A FACT OF LIFE FOR MANY VEGETABLE GROWERS, WITH THE POTENTIAL
TO AFFECT THE COST, YIELD AND QUALITY OF CROPS. A RECENT SCOPING STUDY
LOOKED AT THE MOST COMMON WEEDS THROUGHOUT AUSTRALIA AND THE
CURRENT MANAGEMENT STRATEGIES IMPLEMENTED BY GROWERS, TO HELP
IDENTIFY PRIORITIES FOR FUTURE RESEARCH.
Weeds are a persistent
problem, requiring
constant attention and careful
management. If not dealt with
effectively, they can have a
devastating effect on crop
profitability, yield and quality.
In response to this issue, a
recent scoping study, entitled
Weed Management for the
Vegetable Industry, was led
by Dr Paul Kristiansen of the
University of New England in
New South Wales, with the aim
of identifying the most important
weed species in Australian
vegetable production and the
methods currently used to
control them. The study also
looked at gaps in the current
knowledge of weed control and
identified key R&D priorities.
“Vegetable production is
different to a lot of other ag
industries,” Dr Kristiansen said
of his reasons for initiating
the study. “It’s very intense;
there’s a lot more ploughing
and a lot more changing of
the environment that can be
quite challenging for farmers.
A lot of the practices are a bit
traditional, so we were thinking
about some of the other
industries and how they’ve
modernised the way they
manage weeds.”
The project comprised a
review of literature, a national
survey of vegetable growers,
focus groups and farm visits
in major vegetable producing
regions across Australia.
Common weeds
The national survey showed
that the most commonly found
weeds affecting vegetable
crops were annual or biennial
broadleaf species, including
Fat hen, Stinging nettle, Mallow
R&D
Farm Productivity,
Resource Use
& Management
Managing weeds:
An integrated approach
and Pigweed. These weed types
can be extremely problematic
as they seed heavily and, unlike
grass and grass-like weeds, are
more difficult to control using
selective herbicides.
The Sedge nutgrass was also
commonly reported, which is
problematic due to its persistent
underground root system.
Effective strategies
When dealing with these
common weeds, the current
strategy of most growers is to
use a mixture of herbicides,
tillage or cultivation,
hand weeding, plastic or
biodegradable mulch (where
applicable) and crop rotation.
Other methods, such as
fumigation, biofumigation,
stale and false seedbeds and
farm hygiene may also be used
successfully.
The project found that nearly
all growers integrate a number
of control methods, because no
single technique will effectively
manage the weed issue
throughout the entire growing
season. This is known as
Integrated Weed Management
(IWM) and, while relatively
little attention has been paid
to the practice in the vegetable
industry, the grain and cotton
industries have demonstrated
that IWM is key to sustainable
productivity.
Integrated Weed
Management
Most growers are already using
a basic IWM approach, relying
on a few conventional practices
such as herbicides, tillage
and hand weeding. However,