YOUR INDUSTRY
ECOLOGICAL BALANCE AT THE HEART OF IPM Words by Geoff Lewis
Mike Parker with folder showing 'beneficials'
Mike Parker has been in the growing business for more than 40 years and is currently a member of the Vegetables Research and Innovation (VR&I) board and a director of Vegetables New Zealand Inc.
These creatures would chew holes in his brassicas and render them unsaleable.
Over 20 years ago he was also one of the leaders in the development of Integrated Pest Management (IPM).
“We sat down with the Crop and Food people, now Plant & Food Research Ltd, and worked out how to retain the effectiveness of the products.
IPM is a strategy designed to manage the natural tendency of horticultural pests – insects, weeds and fungi – to develop resistance to commonly used agricultural pesticides. These days, Mike grows sweet corn, maize, rockmelon and watermelons on his property near Hamilton. It wasn’t long ago when he was growing significant quantities of brassicas – cabbages, cauliflower, broccoli, brussels sprouts and forage brassicas – supplying major supermarket outlets with fresh produce alongside LeaderBrand and fellow grower, Mike Arnold, until it became unprofitable to do so. Mike's interest in IPM began in the 1990s when he and Mike Arnold discovered a then new chemistry on the market, methamidiphos, an organophosphate that was useful in combatting the diamondback moth problem.
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“We started to see the development of resistance,” Mike says. “Being an organophosphate, it also killed the beneficials – insects like hoverflies, spiders and ladybirds which would normally prey on the moths and white butterflies (lepidoptera).
“Together, we came up with a process of rotating different products and chemicals that didn't affect the beneficials and to apply chemicals only at various thresholds. “The Crop and Food guys would take us into the field and train us as ‘crop scouts’ determining the level of pest damage in brassicas and lettuce and working out the thresholds for applying insecticides. After doing this for about six months we started getting lacewings everywhere – a beneficial scientifically known as Chrysoperla rufilabris that is widely used to control many different pests. “We also learned about the use of BT – Bacillus Thuringiensis – a bacterial toxin effective in the control of white butterfly.”
