There has been a big swing away from using
pesticides in Queensland's brassica crops.
Department of Primary Industries (DPI) entomologist Bronwyn
Walsh said a recent industry survey found a significant shift
towards integrated pest management (IPM) techniques, reducing
pesticide usage by as much as 40 percent.
Ms Walsh said growers were using a range
of techniques to reduce inputs of traditional pesticides,
including natural enemies of the brassica family insect pests.
"Almost all growers surveyed avoid using
pesticides that harm these natural enemies, with many preferring
to use products that are 'soft' on beneficial insects in
preference to traditional insecticides."
She said the change in practices was
partly a result of a jointly funded IPM project in brassicas,
supported by the Australian
Centre for Agricultural Research (ACIAR),
University of Queensland and
the Department of Primary
Industries.
There were other reasons for the change,
particularly the release of new pesticides that were less
damaging to beneficial insect populations.
Ms Walsh said survey results indicated the
value for growers in having close contact with DPI and other
industry advisers.
Those growers with industry group or
adviser contact sprayed less, were involved in monitoring insect
pest numbers and rotated chemical groups to minimise pesticide
resistance, all sound management practices.
"According to the survey, the use of
chemical group rotation has doubled since 1996, with resellers
reporting that 90 percent of growers follow the practice."
Ms Walsh said pest control was costing
$3.5 million a year in the $34 million a year brassica industry.
"The DPI is heavily involved in a range of
other activities to support the shift away from pesticides.
