Back to the future for IPM
24 April 2019
Entomologist Dan Papacek told the Citrus Technical Forum last month that growers need to get back to the basics of best practice IPM, following a shift away from IPM practice over the last 15 years.
Dan, who established Bugs for Bugs in the 70s, said history is effectively repeating itself, as the industry has been moving back towards reliance on ‘silver-bullet’ chemical solutions.
However, an over-reliance on chemicals will lead to increased resistance, so “effective IPM will help to conserve valuable chemistries.”
“Citrus, almost more than any other crop, has a long history of biological control,” Dan said.
“There are 192 beneficials listed for citrus in Australia alone – and this is not all of them.”
Dan said resistance to organophosphate pesticides in the 70s, particularly red scale and mites that became uncontrollable, drove innovation in IPM.
Aphytis mass rearing began in South Australian and Queensland at that time in a bid to manage red scale. 3-5 releases from early spring occurred at three week intervals and systematic monitoring procedures were developed for both pest and beneficial insects.
Predatory mites were also recognized as valuable aids to mite control. Pollen proved to be a supplemental food that enhances predatory mite numbers. Alternate slashing was developed as a way to provide food and improve environmental conditions for mites and other beneficial species.
Over 20 years, Queensland growers steadily adopted IPM.
Dan said several new compounds then became available in citrus – including Applaud, Confidor Guard, Admiral, Movento and Transform.
They have all proven very effective, and are compatible with biological control agents, although they are still prone to resistance development.
“Over the last 15 years or so we have seen a shift away from IPM practice. The industry has been moving back towards reliance on silver-bullet chemical solutions,” Dan said.
“Chemicals are not the problem – the way we use them is the issue.”
Dan told the audience that although they “probably want to hear about new IPM chemicals, new bugs and new technology, we already have an excellent range of tools”.
“The opportunities lie in better integrating them. This means getting back to the basics of best practice IPM.”
Best practice IPM involves:
• Manage the crop environment to encourage naturally occurring beneficials and maximize the value of any introduced biological control agents
• Introduce biological control agent early in the crop, before pest build up
• Regular introductions work best
• Implement a range of complementary strategies
• Monitor regularly, both pests and beneficials
• Use pesticides sparingly, wisely and with a clear understanding of any side effects
Dan said there although growers need to return to best practice, there are new developments occurring, including new species; more efficient production methods, which will lead to more affordable products; and more efficient release technology, which will improve distribution and reduce labour costs.