Integrated pest management (IPM) has been a recognised methodology in New Zealand for several decades but its uptake and adoption has been slow to non-existent in the arable sector.
This is according to Prof Alison Stewart, CEO of the Foundation for Arable Research (FAR) in New Zealand, who recently shared her experience of developing IPM in practice at an AHDB-organised seminar held during Cereals 2019.
IPM has become an established approach in the New Zealand horticultural sector, with almost 100% adoption by growers.
“The horticultural sector really embraced IPM in the 1980s and 1990s; 80% of our GDP comes from agriculture and horticulture and horticultural produce is high value export produce,” says Prof Stewart.
“The horticultural sector recognised it could get a premium if it developed IPM, so it was very much driven by a marketing strategy.
“With respect to the arable sector, we really did not start looking at IPM until the early 2000s. In New Zealand, arable crops are mainly commodity crops, which go to the domestic market. There was no driver to deliver a premium and so we had a situation where there was not a compelling value proposition for the growers to move down the IPM way.”
But, with an eye on the future, FAR and the New Zealand Government took the decision to start work on arable IPM programmes.
“We could see within five to 10 years we were going to start having major problems associated with agchem availability, residues, resistance and registration issues. We could see things were going to start getting quite challenging for growers.”
FAR won funding to start looking at IPM for wheat, with a focus on using beneficial insects to reduce pest populations and insecticide use, without loss of yield. The research was farm-based, rather than plot-based, and sought to compare IPM and traditional approaches.
“Most growers know what their major crop pests are and recognise them, so there was not a lot of training needed in that space. But most growers did not know what beneficials they had in their farm systems – what they were, what they were doing and how to encourage them. So this was the key area the programme focused on.
“It was about being able to explain the difference between a predator and a parasite, between residents and transients, so the growers could understand different beneficials were behaving in different ways at different times in the crop cycle.”
Participating growers also had to learn to use a range of monitoring techniques, adds Prof Stewart.
Key to IPM is developing an understanding of how crop protection products (CPPs) are affecting beneficial insects. And it is not just CPPs in use in any one crop at a given time, but also those being used at different timings, as they all may have an impact on beneficials.
“So we developed a matrix which showed which pesticides were compatible with which beneficials.
“It was not just insecticides we had to test. We had to test fungicides and herbicides, because they can have a negative impact on some of the beneficial insects. A lot of growers were not aware some fungicides do have partial insecticidal activity.”
Key findings from this work were the numbers of beneficials were higher in the IPM fields and pest numbers were also reduced in these fields.
“We were able to reduce the number of insecticides applied by on average 50% and, with the exception of two sites, we got negligible crop yield differences between IPM and conventionally-managed paddocks,” says Prof Stewart.
Gross margins were improved where an IPM approach was followed, even at the two sites where yields were lower under IPM.
In the final year of the project, the growers were asked to develop an IPM strategy based on what they thought they could do in their management system. This exercise demonstrated that while IPM was seen as making good sense and growers were willing to implement it on their farms, they did not necessarily want to do it themselves, but rather they wanted their agronomists to do it.
“I would say we got about a 25% uptake and this was from those growers who already wanted to reduce the amount of pesticides they were putting on to their crops.
“We had a relatively poor uptake from mainstream growers and the reason is because of the perceived level of complexity associated with getting IPM to work, the fact you have to make the effort to gain a much better understanding of the pest and pathogen life cycles and epidemiology and they believed they would have to accept some crop losses.
“The issue which really became apparent to us was grower uptake and adoption of IPM was going to be driven either by an opportunity, which is what happened in the horticulture sector, or an impending crisis. And we did not have either of those situations in the arable sector in New Zealand at the time. We could not get a premium and growers still had lots of chemicals available and were still getting good control.”
But, fast forward to 2019 and the situation is completely different, says Prof Stewart.
“We have got 47 major groups of chemicals under review by our EPA at the moment. If we look out five to 10 years, the signals are clear; we are not going to have the number and variety of chemicals we have had before.
“We are in a situation now where we have to develop what we are calling a ‘lighter touch’, in the sense that we recognise we are not going to go spray-free but we have to transition to using synthetic inputs only when absolutely necessary.
“We have done a huge amount of work over the last 10-20 years on IPM systems and so we can bring all that back now because we have got that impending crisis; we have got that environment where growers are going to have to embrace new technologies and change their management practices.”
What is more, within the last decade there have been huge advances in other pest control technologies, which can now be integrated within an IPM approach.
“Probably the area which has grown the most is the development of biopesticides,” says Prof Stewart.
FAR is taking a proactive approach to the integration of biopesticides within an IPM approach, including scanning markets overseas for products with potential for use in New Zealand and co-funding product development with smaller biopesticide companies in New Zealand.
Cultural pest, weed and disease control practices, including solarisation, mechanical weeding and biofumigants are also being revisited.
A new five-year, NZ$30 million (£16m) cross-sector project will further develop the ‘lighter touch’ IPM approach and will include development of a wheat IPM programme.
New Zealand is aiming to reduce its use of agrochemicals on wheat by 50% within the next three years. It is an ambitious target but FAR has already demonstrated to its growers that it is not an unachievable one.