Trials, Tribulations and Successes of IPM

BCPC 7th Annual P&B Review Meeting Report

Dr Jon Knight (Freelance Consultant Agriculture & Environment)

This was the seventh Annual Review of BCPC’s Pests & Beneficials Group. First established in March 2015, the purpose of the group is to provide a forum for discussion of relevant research results and new legislation and new legislation, and impact on integrated pest management.

The objective of this meeting was to better understand how to deliver practical IPM solutions to farmers. This starts with the policy context, followed by research that can be done and finally the delivery of tools and information to famers and the successful implementation of IPM in the field. The meeting also sought to highlight the need to integrate the thinking about the implications of combining IPM management decisions for insect, disease and weed pests and the trade-offs that may have to be made as a result.

INTRODUCTION: Cathryn Lambourne, Knowledge Transfer Manager from Agrifood section of the KTN (Knowledge Transfer Network), UKRI.

Cathryn provided an account of the work of the KTN, particularly in the Agrifood sector, providing support for those seeking information, funding, and connections within the industry followed by a short outline of the principles of IPM.
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IPM IN THE FIELD – THE CONTEXT

Review of IPM related policy and hoped for outcomes – Anna Morgan and Paddy Vasey, Pesticides Hub, Environmental Quality Directorate, Defra

The first talk provided information on the review of IPM related policy and the hoped for outcomes. An update on the review of the National Action Plan (NAP) was provided, which had been delayed from the end of last year to provide additional time to understand better how it might deliver IPM alongside possible revisions to pesticide registration. IPM has been identified as a major component of the NAP and will be strongly linked to the sustainable farming incentive (SFI). Rather than focus on revisiting the NAP Anna and Paddy asked for audience participation to provide feedback on what is important for IPM delivery. Five methods of supporting IPM implementation were presented and the audience asked to rate the importance of each of these to farmers on a scale of 1-10. These were, Advice; Guidance; Formal training; Peer-to-peer learning and knowledge transfer; and Decision-making tools. Advice featured strongly (average score of 8.2) with peer-to-peer learning (7.7) just behind. Guidance (7.0) and decision-making tools (6.6) were slightly lower and formal training the least highly rated (5.8). The next question was “What can government do to best support in the delivery of practical IPM solutions to farmers? The responses were free text but some common themes were around the following:

• Funding for the development of IPM related research
• Learning from those farmers who have successfully implemented IPM;
• Fund existing groups to deliver on Knowledge Exchange;
• Provision of independent advice;
• Benchmarking of IPM systems;
• Economics is a critical constraint to IPM adoption;
• Registration of IPM friendly (bio)pesticides.

In total over 100 answers were provided by the attendees and these will be used to help inform the NAP. Anna Morgan recognised a key constraint to adoption was the unfavourable economics of IPM in many cases and said that funding under the SFI is likely to provide some support.
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Outcomes of the Defra SFI survey on IPM implementation and VI survey on the adoption and use of IPM
Henry Creissen, SRUC.

Henry provided an overview of IPM adoption in the industry, a crucial stage in making IPM a success. The survey showed that 5000 IPM assessment plans in Scotland, Wales, Northern Ireland, and England have been completed (4723 in arable and 292 in grassland). Differences between countries were evident; often influenced by cropping opportunities, cultivation methods and soil types. Some key differences were, regular ploughing is the preferred option in Scotland whereas in England there was a greater diversity across direct drilling, min-till and ploughing. The importance of different pests varied across countries but also by region. Wetter regions had more problems with slugs, whilst Blackgrass was a far greater problem in England and Wales than in Scotland. Stale seed beds were used widely in England and Wales but not Scotland or N Ireland, largely down to climatic differences.

This insight shows that research could and should be regionally targeted to ensure greater relevance.

The review revealed factors that influenced farmer decisions on the adjustment of spray programmes. Key ones were prevailing weather conditions and forecasts, BASIS qualified agronomists and observed levels of pests within a crop. Analysis of different behaviours between high and low scoring IPM adopters revealed that the top 25% put significantly more effort into prevention measures than the bottom 25%. There was also a strong correlation between the area of a farm and the IPM plan score, influenced by factors such as availability of labour, use of independent advisors and availability of resources. The preferred Information source was agronomists for both arable (80%) and grassland (65%) with farmers citing this as their main source of advice. Overall, the IPM assessment plans have been very useful in providing an insight to farmer behaviour and identification of what is and isn’t thought to be useful and how widespread IPM adoption is across the industry. It is hoped that a similar system will be released for horticulture this year.

Crop specific IPM plans have been and are being developed under funding from the Environmental Land Management schemes (ELMS) with funding from Defra. These plans allow a farmer to see what IPM tools are available, record their current use of IPM, adopt new measures and document the improvement in their IPM score. This work identified key barriers to uptake of IPM practices such as ‘economic’, ‘lack of knowledge or understanding of IPM’, and ‘existing mindset or habits’.

Finally, Henry concluded by reminding everyone that delivering IPM is the responsibility of all in the agrifood system to share knowledge and the additional risk and cost of adoption and adaptation.
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CASE STUDIES OF IPM IMPLEMENTATION

Integrated Pest Management strategies for cabbage stem flea beetle (CSFB).
Sam Cook and Patricia Ortega-Ramos, Rothamsted Research.

The following talks presented some of the practical solutions and experimental work underway to provide the necessary tools and to better understand and implement IPM in the field. CSFB adults and larvae are both pests of oilseed rape (OSR), with emergent seedlings damaged by the adult and then larvae subsequently burrowing into stems. Historically pesticides worked well to control problem. The neonicotinoid ban in 2013 and the development of resistance to pyrethroids, now widespread, has resulted in significant losses to this pest. The adult is now the major problem often leading to complete destruction of the crop at or around emergence. The impact of conflicting EU policy was highlighted with the renewable energy directive encouraging the growing of the crop in 2009, but the neonicotinoid ban in 2013 to prevent harm to bees resulted in massive crop damage in fields. The UK area of OSR is now at a 20 year low with a 46% decrease since its peak. The unintended consequence of this has been the increase in imports from other countries where neonics are still used, thereby exporting the issues and problems.

IPM is the solution to CSFB problem using 4 key steps.

• Action thresholds – available but developed for use with insecticides so need to rethink threshold in terms of physiological damage to the plants. High levels of injury (up to 90%) does not necessarily impact yield but damage levels are often above this resulting in yield loss. Declines in yields are seen when there are 25 CSFB larvae per plant; plants were shorter had fewer flowers and pods and a lower oil content but little impact is seen when fewer than 5 CSFB per plant. The current larval threshold may be too low but 5-25 larvae per plant are damaging so monitoring is essential.
• Early sowing strategies to avoid adult damage require caution as this can result in higher larval damage as the egg laying period is extended. Weather can have a large influence on timing of migrations so later can sometimes be the better option. Leaf area damage could be used as a threshold, but it is time consuming, and apps and computer tools still need improvement. New methods of detection such as optical sensors using lasers combined with neural nets to identify and count CSFB give 80-95% accuracy and good correlation with trap catches. These could be used to identify and treat hot spots in fields.
• Prevention of damage by planting resistant cultivars is not currently available but work is looking for suitable traits within varieties in the Oregin accessions. Similarly
  companion planting is being looked at but is not yet optimised. Trap cropping using turnip rape was shown to significantly reduce CSFB damage in 2005. The use of turnip rape trap crops is now being repeated with current varieties and is showing some promise. Companion planting or nurse plants is being investigated but it is not yet clear how it works. Other interventions such as longer rotations, minimum tillage, long stubble and use of organic matter have shown some positive impacts.
• Controls using new insecticides with RNAi technology, biopesticides, entomopathogenic fungi and nematodes have been shown to work in the lab now need testing in the field. The use of conservation biological control shows some promise with recent work showing 33% parasitism from Tersilochus microgaster in larvae and Microctonus brassicae being found in96% of fields and attacking adults at a rate of 36%.

Even with all these options there is still much to be learnt to make the elements work together and find ways to incentivise farmers to use them.
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Implementation of IPM for control of aphids and BYDV in cereals post-neonicotinoids
Alan Dewar, Dewar Crop Protection

The second talk in this section followed the principles of IPM used within the sustainable use directive and applied them to the management of cereal aphids and BYDV.

The first step for IPM is to understand the biology of the pest and how it damages the crop and the various species of aphids and the associated strains of virus were described and problems around reliable identification highlighted. Currently 95% of insecticides on wheat are used against aphids and resistance to pyrethroid insecticide has been found in the grain aphid (approximately 50% of the population) and one example in the bird cherry oat aphid in Ireland.

Monitoring is the next step which can be done with a range of traps but all generally require a high level of entomological expertise, which is not always available or lack of it leads to misidentification. Information from suction traps is available from Rothamsted but also via the AHDB aphid monitoring network web site. An example describing how to understand possible outcomes or forecasts using suction trap catches comparing current catches and historic means was given showing early and extended migration tends to lead to high levels of BYDV the following spring. Alan predicted that there was a low risk of significant BYDV levels this spring.

Decisions made based on monitoring and thresholds are important to ensure action is taken only when needed, however there are few reliable thresholds and these often lack supporting data. The provision of an infectivity index by region would give greater confidence in making “to spray or not to spray” decisions.

Control using non-insecticidal methods can be used to reduce risk by delaying drilling until the threat of immigration has passed. This has the benefit of also being useful for blackgrass control too but can result in yield reductions. Destruction of volunteers before sowing (green bridge) must be done long enough before sowing to be effective. Resistant varieties are now on the market and offer another tool.

The reduced use of insecticides through withdrawal of the neonicotinoids has occurred but these have been replaced by widespread and often repeated application of pyrethroids which will damage non-target species too. Weather has a significant impact on use but since only pyrethroids are available there is no option for resistance management. The evaluation of the use of the various IPM options needs monitoring to identify higher risk areas and which tools work best.

In the future the possible use of RNAi technologies for aphid or virus control or the development of kits for in-field identification of aphids and the presence of virus would lead to better decision making.
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TOOLS FOR IPM

Stepping Up IPM. Promoting improved IPM decisions and demonstrating that IPM works
Mark Ramsden, ADAS

Whilst there have been many Decision Support Systems (DSS) developed across Europe their existence is often unknown or it is not clear if they can be used outside the development region. Mark presented progress on two related EU funded projects, IPM Works and IPM Decisions. IPM Decisions is looking at nearly 100 different Decision Support Systems (DSS) from across Europe and IPM works is a demonstration network to share information and tools across countries and follow implementation progress of these tools. Part of this process is an analysis, using a series of workshops, of why some tools get used more than others.

The objective is to provide a single DSS platform that allows farmers quick access to any or all the DSSs collected by the project. The tools will be adapted, where possible, for use in other regions with relevant information on the process of adaptation and validation of their performance. A preview of what the system will look like when completed was provided. It is designed to automatically detect the user’s location and allows input of relevant information to inform the system and is due for launch later this year. The system will allow comparison of different models for the same pest, if available, and information on the models can be obtained within the system. There is also a facility for researchers and developers to create new models or adjust models to local conditions.

A series of workshops have been held alongside the platform work to gather information on the ecology of pests and the presence, or levels, of resistance along with socio-economic variables.
Some brief findings are that,
Farmers:

• almost all have smart phones/computers;
• 50% are already using already using a DSS;
• are generally willing to use new technologies.

Agronomists:

• confident that DSSs complement their work;
• most believe DSS are generally accurate (however UK advisors are a bit more sceptical);
• majority recommend farmers use DSSs but takes time to get adoption;
• don’t currently provide support on which DSS to select.

Results from the workshop also show that DSSs are generally more widely used by
farmers with larger farms, higher levels of education, higher value crops (e.g., vegetables), and greater exposure to technology. Whilst making DSSs more widely available will be a significant step forward it is important that both the technical and socioeconomic factors are considered.
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TOOLS THAT WORK FOR FARMERS

IPM implementation – the independent advisor’s perspective
Sean Sparling, Association of Independent Crop Consultants (AICC)

This talk was a personal perspective with information from Sean’s personal experience and that of many other AICC members.

The starting position was that everybody has heard of IPM and most advisors and farmers fill in their IPM plan with growers often taking the lead. It is a vital part of crop production and has been for many decades. The principles of IPM have been applied in the past but not always with the name of IPM often called a common sense approach or sound husbandry. IPM should be applied across all pests , i.e., insects, weeds and disease and needs to involve many different elements and approaches, rotations, cultivations, varietal choice etc. and if no other solution, pesticides. An example of the need to look more widely at management actions is the case of blackgrass management where delayed drilling to reduce herbicide use has also provided other benefits by reducing levels of BYDV.

A key difference between “conventional” approaches and IPM is that both the grower and advisor must understand and appreciate the risk and the fact that things may and do go wrong. Where IPM has proven benefits then it is often easier to get implemented, if unproven then implementation is less likely as the risk may be perceived to be higher.

IPM needs to be implemented more widely in insect control especially because of harmful impacts of insecticides on beneficials and the subsequent impact on longer term control of pests. IPM is inherently more risky than conventional approaches and the litigious nature of life means there can be serious consequences for getting it wrong which makes both grower and advisor risk averse. Advisors can help uptake by explaining the consequences of getting it wrong but then support the grower by committing to monitoring the crop and advise insecticide use only if the threshold is reached.

Information from AHDB, Syngenta and others in the form of forecast tools can inform decision making but ultimately it is the advisor or grower who is left to make the final decision using the supporting information. Any farmer being advised to spray or not, should ask for an explanation and evidence why that is the case. By showing growers the evidence e.g., money spiders present in large numbers so no need for aphicide, can be revealing and informative for the farmer. There is a need to develop tools to assist in understanding the likely impact of beneficials on pests, a beneficial threshold, to aid decision making. Similar work on the impact of releasing predators within the crop and their impact is also required.

Sean stated that science and IPM is the way forward and cited his example of not spraying pollen beetle for 20 years with field trials showing no benefits from spraying. He also gave other examples of not spraying leading to at least as good outcomes than if a crop was sprayed.

IPM is something that you must go all in with, and you need to have the nerve to carry through. Benefits can outweigh the risk, but there is a need to understand the whole system so the small gains from different actions can deliver success collectively. The provision of novel tools from new and emergent technologies provide an opportunity to improve IPM significantly. Advisors need to be confident enough to trust themselves and growers to trust their advisers. Advisors and growers are responsible for making decision but having the necessary tools and information to support decision making is vital. IPM is inherently risky and there is a need for policy makers to acknowledge this and try to support grower adoption without undue risk, financially if necessary, by providing an enabling policy framework.
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The Quest for Effective IPM – the farmer’s perspective
Andy Barr, A&A Barr Farms, Kent

Andy provided an account of his experiences on his own farm over the last 10-15 years. It is important to realise that IPM is not just a tick box exercise, a response to an impending visit from assessor as is sometimes the case and it is also important that there is sufficient encouragement to change practices and government policy provides more incentive for change without undue penalty.

Andy uses a whole systems approach using direct drilling, cover crops, rotations, resistant varieties, and other tools. Cultivation is particularly important since residues left from direct drilling give a whole new habitat for beneficials to survive in and Improves soil health too, but does it work? Andy hosts Syngenta trials on conservation agriculture and a comparison of direct drilling, minimum tillage and ploughing has been made. There are very obvious differences in establishment and early growth and the consequent ability to withstand the impacts of CSFB. Plants established in ploughed land were hammered by CSFB with less damage in the min till field and the least damage in the direct drill field. Additional evidence of the benefits of changed tillage are the significant rises in bird sightings and earthworms on farm. Many more carabid species were also found by University of Greenwich researchers.

Conservation agriculture is undoubtedly more difficult but the adoption of better technology has allowed improved establishment of crops and cover crops through RTK guidance on the drill which provides 2cm accuracy thereby allowing placing of a companion crop between crop rows. The importance of the right machinery is highlighted by trying a straw rake to control slugs which worked but it also dragged weed seeds about rapidly spreading the problem.

The adoption of a Vaderstad cross cutter disc now allows control of slugs without increasing the weed problem. Other indicators of success of conservation agriculture are numerous money spiders in longer stubbles that can impact aphid numbers. However, the cross cutter reduces stubble height which impacts the spider numbers. Habitat management has also been used to improve biodiversity. The farm field margins have evolved over the years going from ploughed fields and bare wire fences to substantial hedgerows and cover crops and managed margins. The use of wildflower mixes requires careful management and the destruction of key weeds such as blackgrass is vital before trying to establish the flower mix as it is not possible to remove it later. There are also substantial costs to this work and sometimes the payments do not cover the cost of implementation.

There is a need for a variety of actions to achieve success and by stacking them together in a field the sum of the small improvements can yield successful outcomes, however, weather can still impact on the success of actions notably on the arrival time of CSFB in a field and also autumn aphids and BYDV transmission so it is hard to make the “right” decision, all that is possible is the best decision given the information available. Another technique that has been tested is the addition of Organic matter which has worked in some locations but as it requires incorporation it is not compatible with direct drilling. Resistant varieties have also been tried but invariably the yield is poorer than the mainstream ones and currently they are not economically viable on Andy’s farm.
Early trials with a microbe broth to improve establishment through nitrogen fixing and other bacteria combined with the use of silica compounds to strengthen stems has shown some promise with CSFB larvae appearing to do less well on the crop.

There is a need to establish robust and reliable thresholds with many current ones having little or no supporting evidence. For IPM to work these are essential.
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