Published on 03/02/2021
"I never in a million years thought I’d be interested in this,” says FMC New Zealand’s southern area business manager and resident integrated pest management (IPM) enthusiast. “But it’s so practical and logical, it’s very easy to advocate for it. Once you understand it, it becomes quite obvious that it can be done. What surprised me at the start was the simplicity of it all!”
He’s talking about helping operationalise IPM across large areas of forage brassicas over the past few years, adopting techniques that were commonplace in horticulture at the time but not so prevalent on farm. The turning point came after the NZ launch of Exirel insecticide in 2014. “We knew we had a very IPM friendly product, and we also could see the industry needed to upskill to get the best out of it as a forage brassica product. So that’s when we started bringing overseas experts into NZ to improve our knowledge, and also started to make that push into training.”
He includes himself in the need to upskill – from today’s perspective he says in hindsight his knowledge of IPM was ‘minimal’ six years ago, but with exposure to overseas expertise, as well as to scientific studies on Exirel here with Plant & Food Research, that changed. As has the market. “Five to six years ago, reps and farmers would walk into the crop, see damage, and spray. We’re now walking into the crop weeks earlier, looking for eggs instead of damage, and watching to see how populations build up before deciding what to do in the way of control."
A key understanding with application of IPM principles to a large crop like forage brassicas is that the beneficial insects are already present, he says. “It’s not something we have to ‘add’. If you think back to when the parasitoid wasps for cloverroot weevil were introduced to NZ, they had to be released on-farm to get established. We don’t have to do anything like that.”
What is required is observation and identification, especially at this time of the season. The larvae of two predator insects in particular are well worth knowing, he says – hoverfly, and brown lacewing. Both have a big appetite for common pests like aphids, with hoverfly larvae having the biggest impact, followed by lacewing larvae, then ladybirds.
Farmers and field reps are also encouraged to know their parasitic wasps, of which there are five species known to control pests such as aphids, leaf miner,white butterfly and diamondback moth. “A lot of times we get asked to come have a look, because there’s a bug in the crop. Often it’s a beneficial, and that’s where the growth in IPM has come from– in many cases farmers didn’t realise how many beneficials were around, or what they did.”
He stresses that IPM is not about not using insecticides, but rather using them in the most appropriate way, minimising the impact on beneficials and maximising the impact on target species. And the benefits range from the immediate to the systemic, for both farmers and those helping them with input decisions. “The primary goal is to have a plan for the crop from the time the seed is planted right through to the time it’s grazed. What typically comes out of this is a reduction in the overall number of sprays, with no change to crop yield, and so a lower cost of production. ”
In this context, Exirel has an excellent fit. “But what we’ve also found is that when people learn the principles of IPM, they not only end up with a better understanding of pests and beneficials, they also have a greater understanding of all the insecticides and different chemistries that are used in the crop. That’s because they need to know their active ingredients, how they all work, what their residuals are and how they can be used alongside Exirel as part of a programme. So as well as understanding and confidence in IPM systems, they end up with a really good working knowledge of insecticides in general.”
McKay is pleased to see IPM becoming much more mainstream in forage brassicas than it once was. “It’s good, because there’s a lot of change going on out there. And this fits right in with some of those changes.”
For more detail contact your local FMC NZ area business manager.