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Phyto-threats workshop

Improving nursery resilience against threats from Phytophthora

6th October 2016, APHA, Sand Hutton, York

Workshop full report

Sarah Green, Phyto-threats project co-ordinator, welcomed everyone and introduced the aims of the workshop. The aims of this first workshop were:

  • to introduce the scientific aims of the project
  • to develop collaborative networks across individuals and groups with an interest in working towards collective best practice in nurseries
  • to share lessons and experiences around the challenges and opportunities of managing disease threats
  • to identify nurseries and other stakeholder groups and individuals who could and would become involved in the research

The meeting was attended by c45 academics, nursery managers, Plant Health inspectors, foresters, policy makers and others

Richard McIntosh (Defra) provided a policy context for plant health in the UK. He emphasised the value of healthy landscapes and the benefits they can provide. Increased vigilance is important but also having the capacity to quickly intervene in the event of an incursion. Richard outlined the 5 ‘Ps’ approach (predict, prevent, protect, prepare, partnering) and highlighted the range of approaches the government is taking pre-border, at the border and inland. He posed a challenge to the audience to think of how they could incorporate a 5’Ps’ approach to their business.

Mike Harvey (Maelor Forest Nurseries) highlighted the changes they have seen in their nursery over the last 20 years, particularly in the numbers of new pests and diseases and he noted the limited range of tools that nurseries have to deal with damage and control. Maelor have invested in Integrated Pest Management which guides use of water, clean areas and purchasing behaviour.

Ian Nelson (Johnsons of Whixley) presented a trade perspective and noted the complexity of the trade network. Business is largely driven by price and profit. He said that UK growers currently cannot meet the UK demand for plants and therefore import from abroad. However, he recognised that the inspection regime in other countries may not be as robust as in the UK. Ian called for greater education amongst customers such as landscape contractors to look for alternatives to plants that can host serious diseases

David Edwards (Tilhill Forestry) started by describing the devastating impact that Phytophthora ramorum has had on larch forests in South Wales. David explored the efficacy of different approaches to deal with P. ramorum but also the huge challenges of trying to predict the next outbreak. He made a plea for prevention rather than cure for tree health and warned that any solutions should not impact heavily on the economics of forestry (e.g. abandoning Sitka Spruce).

A panel discussion chaired by Sarah Green (FR) elaborated on some of these challenges, highlighting the dilemmas of ‘unknown unknown’ as well as ‘known unknown’ harmful organisms. The use of correct tools for detection was said to be important and discussions touched on the closure of high risk pathways. The value that plants add to the environment is believed to be highly under-valued by society, which facilitates the desire for cheaper products and imports. Reducing bureaucracy was considered to be key to making changes in the sector as well as seeking opportunities to increase the quality and quantity of UK plant production.

Each of the 4 project Work Packages presented a 5 minute introduction to their work.

Work Package 1 (presented by David Cooke from James Hutton Institute) focusses on understanding Phytophthora distribution, diversity and management in the UK nursery system. The team are developing a diagnostic system that can detect Phytophthoras and identify individual species using DNA methods. The team have been collecting samples at a number of nurseries. David thanked the nurseries who have volunteered so far and welcomed more participants.

Work Package 2 (presented by Mike Dunn from Forest Research) involves social science and economics. The core focus on WP2 is a feasibility analysis and development of ‘best practice’ criteria. The research will involve exploration of nursery practices and issues they deal with on a daily basis as well as attitudes towards best practice guidance and accreditation. A consumer survey will be undertaken to understand better plant purchasing behaviours and public attitudes towards accreditation and what this could entail.

Work Package 3 (presented by Bethan Purse from Centre for Ecology and Hydrology) involves modelling global Phytophthora risks to the UK. The team are mapping trade pathways from source countries and ecological zones and linking ecological traits of all known Phytophthora species globally to likely impacts if they were to arrive in the UK. They are looking to learn lessons from past introductions in order to develop a predictive tool.

Work Package 4 (presented by Sarah Green on behalf of Paul Sharp from the University of Edinburgh) will look at predicting risk via analysis of Phytophthora genome evolution. Questions that this work package will explore include how Phytophthoras have evolved to kill trees, why they are so adaptable and how they can hybridise. The team will sequence the genomes of three Phytophthora species which will add to a comparative analysis of genomes across a range of Phytophthoras.

Two international speakers provided an overseas perspective on Phytophthora risks and nursery accreditation. Susan Frankel (US Forest Service) focussed on California and the impact of Phytophthoras on native plants and wildlands. She noted the unintended consequences of restoration projects that are introducing Phytophthoras. The US National Plant Board have started a certification scheme with 8 nurseries currently signed up (pilot phase). Susan emphasised that complying with the certification standards required a lot of work but the nurseries involved are then free from intensive inspection per pest. There is also a voluntary accreditation scheme that involves following best practice guidance. Susan recognised that the scheme was not easy and she said you couldn’t claim to be Phytophthora-free but you could claim to have done everything possible to be disease-free following a systems approach. Giles Hardy (Murdoch University, Perth) was unable to attend in person but presented a video on the Australian NIASA scheme whereby production nurseries and those involved in growing media sign up to follow best practice management guidelines. This scheme has been in operation since 1997 and the guidelines are now in their fifth edition. Giles described the guidance in detail including crop hygiene, crop management practices, general site management and water management. Giles also described in detail a method for composting. Alongside the nursery accreditation guidelines there is also a national nursery and garden industry biosecurity plan which focuses on risk mitigation.

There followed a workshop session led by Mariella Marzano (Forest Research) to explore what a nursery accreditation scheme would look like in the UK. Feedback suggested that accreditation might need to be tailored for different stakeholders but possibly under a single umbrella. A scheme could include different levels of standards to encourage businesses to improve their practices. A number of practicality issues were raised and need further exploration. However, there was a strong consensus that any scheme should have minimal bureaucracy. It was felt that there would need to be consumer support for any scheme to provide an incentive for nurseries to be involved. Decisions over what the scheme should include would best be made by representatives from a mix of sectors. Brexit might provide an opportunity for the UK to promote its own best management practices and to have more control over quality of imports. There are practices (e.g. mail orders, garden shows, illegal trade in plants) that could undermine an accreditation scheme. The scheme would require consumers to be informed and supportive.

Jon Knight gave a keynote listener talk, reflecting on the day’s discussions. He emphasised that we need to understand market constraints and explore how to ensure that regulations and legislation work better for the sector and consumers. He noted that capacity will have to be increased if we are to produce more ‘home-grown’ plants but businesses need to be profitable in order to keep trading and that currently involves importing from abroad. He highlighted that if there is a desire to change trading practices then consumers need to be willing to pay more for ‘home-grown’ plants and that involves recognising the value e.g. of a disease-free environment. He made a plea for models to provide some foresight on future risks to facilitate traders becoming more resilient.