Agriculture

With plentiful rain and long summer day lengths, Scotland producing some of the highest yielding and best quality crops in the world. But conditions that promote good crop growth are often good for pests and pathogens too and in Scotland 15-20% of our crops are lost to pests and diseases annually. 

These losses to pests and diseases   amount  to almost a million lost tonnes per year with a value close to £200 million. Dealing with the endemic disease burden  inevitably means higher prices in supermarkets, hard times for growers  and a knock to the economy but, in addition to this current burden  many more pests and pathogens are arriving or threatening our borders.  Priority concerns for the sector are sustainable methods of reducing and managing pest and disease risks that lessen reliance on pesticides. Current acute issues which have been highlighted by stakeholders  are pesticide resistance developments in some of our endemic pests and diseases, and also concerns over product withdrawals through the regulatory processes. Concerns over resistance development in endemic diseases are a major plant health concern in many crops in the agriculture sector. Potato blight and ramularia in barley being two current example where new issues emerged in 2017.

 

Knowledge Bank

IPM Plan

Projects

Sharing solutions between sectors: what methods are deployed in tackling pests and diseases?
Project Lead: Steve Woodward
Discussions at the PHC launch event, and between sector leads, indicate some distinctive and different approaches to tackling pests and diseases in Scotland are to be found across sectors and between businesses/units. Some focus on direct interventions (e.g. use of chemicals), whilst others have largely considered indirect interventions (e.g. manipulation of age structures), and understanding of integrated approaches is patchy. There is an opportunity to gather together a guide to the different approaches – which could propose a typology and set of definitions of solutions that could be used by subsequent PHC communications; provide a basis for cross-sectoral dialogue; provide a basic mapping of how the solutions are currently used by sector; and help identify untested combinations of solution and setting which could be developed.

Impact: Improved understanding of concepts and options amongst stakeholder community in Scotland; a basis for gap analysis by PHC.
The use of mobile technology to enhance plant health monitoring and awareness in Scotland
Project Lead: Sebastian Raubach
Plant health is a major issue worldwide with many different pests and diseases threatening different plant-based sectors, e.g. forestry, agriculture, environment and horticulture. Keeping up to date with such threats has always been a major task in terms of pest and disease identification, geographic spread, monitoring and coordinating responses etc. yet, in the world of mobile technology, we now have an opportunity to achieve some of these things from apps on our phones. Questions around the use of such technology include: What options are available in terms of mobile technologies for plant health?; What is their primary purpose?; Who are they targeted towards - farmers, plant health professionals, citizen scientists etc? Are they accurate and reliable? Do they provide real time information to a central database?; Who uses such a database?; Which sectors are they designed to work in or are they cross sector?; Do they have global use or are they limited to certain geographic regions? A review of such technologies is needed to ascertain which are most appropriate for use in Scotland across a range of sectors, which could be further adapted to achieve this aim and, if further development is required, what are the key elements of such a technology that would need to be incorporated into such a mobile application?

Impact: Improved risk assessment; better equipped stakeholders and government plant health officials; improved coordination of plant health activities in Scotland.
Risk mapping of the likelihood and impact of a Xylella fastidiosa outbreak in Scotland
Project Lead: Kevin Watts, Samantha Broadmeadow
Xylella fastidiosa is a bacterial plant pathogen that can cause disease in a broad range of hosts. Disease symptoms include leaf scorch, wilting of foliage, dieback and plant death. Xylella fastidiosa was first detected in Europe in 2013 in Puglia in Italy and was identified as subspecies pauca which has gone on to devastate olive plantations in this region. There are currently major Xylella outbreaks in Southern France, including Corsica, Italy, mainland Spain and the Balearic Islands.

Although Xylella has so far not been detected in Scotland, an outbreak would have serious impacts on any host plant-related activities/businesses and the wider environment. An essential aspect of ensuring Scotland’s preparedness for the possible arrival of Xylella is to prepare a risk map for the likelihood of the arrival of Xylella together with the consequences for key elements of the Scottish economy (directly and indirectly impacted) in the event of an outbreak. Data relevant to the risk mapping for Scotland would include location of sites involved in plant imports, volume of plants imported, impact on business trading in plants if an outbreak is detected and the wider environmental impact.

Impact: This project will contribute to Scottish Government’s contingency and preparedness measures for the possible arrival of Xylella fastidiosa by mapping the risk of likelihood and impact of an outbreak.
Identify the presence of potential insect vectors of Xylella fastidiosa in Scotland
Project Lead: Kirsty Park
Xylella fastidiosa is a bacterial plant pathogen that can cause disease in a broad range of hosts, including Polygala myrtifolia, Olea europaea, Rosmarinus Officinalis, Lavandula sp., Prunus sp. and Nerium oleander. Disease symptoms include leaf scorch, wilting of foliage, dieback and plant death. Xylella fastidiosa was first detected in Europe in 2013 in Puglia in Italy and was identified as subspecies pauca which has gone on to devastate olive plantations in this region. There are currently major Xylella outbreaks in Southern France, including Corsica, Italy, mainland Spain and the Balearic Islands. The bacteria are transmitted by xylem feeding insects from the Cercopidae family, which include froghoppers and spittlebugs.

There are several species of insects that could vector Xylella fastidiosa in the UK including the meadow spittlebug (Philaenus spumarius), which is very common in Scotland. An outbreak of Xylella in Scotland would have serious impacts on the affected grower/nursery and any other host plant-related activities/business within a 5km buffer zone. Therefore, in order to establish the potential for these bacteria to spread, should they be introduced, it is important to identify and get an understanding of the abundance of potential Xylella vectors in Scotland. The WrEN project (http://www.wrenproject.com/), presents a unique opportunity to make use of existing insect collections to map the occurrence of potential Xylella vectors within agricultural woodlands across Scotland. Since 2013, partners on the WrEN project have surveyed over 130 secondary and ancient woodland sites for habitat and wildlife in two regions of mainland Britain. To date, over 1100 species have been recorded from a wide range of taxa. Vegetation structure has been characterised at all sites including information on tree species richness, tree density and size, understorey and canopy cover. In addition, the surrounding landscape has been mapped at a range of spatial scales up to 3 km from each site.

Impact: This project will contribute to Scottish Government’s preparedness measures for the possible
arrival of Xylella fastidiosa by identifying and mapping the distribution of potential vectors of Xylella
in Scotland.
Assessing the potential of the psyllid Trioza anthrisci to vector Liberibacter solanacearum (Lso) in Scotland
Project Lead: Fiona Highet
The unexpected finding of the presence of Lso and a potential vector species in Scotland raised significant concerns (Sjolund et al. 2017). However, without further information this cannot be put into context. The likelihood is that the disease and possible vector have been present in Scotland for a long time, and yet our crops remain symptomless. Therefore, without the introduction of another vector risk may remain low. In order to confirm this and establish the current risk of transmission to crops, the following information is urgently required: the distribution of potential pyllid vectors including T. anthrisci in regions of Scotland, the presence of Haplotype C Lso within these vectors, a genomic comparison of the Scottish Haplotype C Lso with disease-causing Haplotype C Lso from Finland and Spain, and establishment of T. anthrisci’s vector potential through the development of a breeding colony.

The knowledge required to identify different psyllid species is highly specialised but is essential in order to gain a wider understanding of the disease threat that such insects cause. As few in Scotland have this specialisation (including SASA), it is deemed important to up-skill others by running a training course on psyllid identification for entomologists within Scottish organisations to better enable Scotland to deal with possible Lso threats both now and in the future.

Impact:
This project will contribute to Scottish Government’s ability to control pests / diseases by increased knowledge on the presence and distribution of Liberibacter solonacearum and its host psyllids in Scotland and the potential of these organisms to cause and spread disease.
Impact on Scottish crops if the molluscicide metaldehyde is withdrawn
Project Lead: Fiona Burnett
This report sets out estimates for the crop loss and value to Scottish crop production should the molluscicide metaldehyde be withdrawn. This would leave ferric phosphate as the only available chemical control option. Short term losses are negligible as the substitution of ferric phosphate carries no additional treatment costs and has equivalent efficacy. Longer term there is some risk should resistance arise to this single site mode of action active, and ferric phosphate (although of lower mammalian toxicity to metaldehyde) has some environmental impacts of its own.

Publications

Forestry, Horticulture, Agriculture, Environment | Final Report and Policy Document

PHC2020/09: Economic Impact of Pesticide Withdrawals to Scotland, with Case Studies

Authors: Fiona Burnett, Mark Bowsher-Gibbs, Donald Dunbar
March 2021

Chemical forms of plant protection are widely used in Scottish agricultural, horticultural and forestry production plus for amenity and natural environment management purposes.  The availability and use of active substances in pesticides are closely regulated and increasing concern over human health and environmental impacts has led to a greater likelihood that some existing approvals will be withdrawn and/or that approvals for new products will not be granted.  Potential impacts from withdrawal of these pesticides are of policy interest and this summary report builds on the data and results from project PHC2020/15 (Potential impacts arising from pesticide withdrawals to Scotland’s plant health) and uses case studies to understand the likely magnitude and distribution of potential impacts and how they may be mitigated. 

Forestry, Horticulture, Agriculture, Environment | Final Report

PHC2018/15: Potential Impacts Arising from Pesticide Withdrawals to Scotland’s Plant Health

Authors: Andy Evans
November 2020

The use of pesticides to manage plant pests and diseases is a key management intervention across plant health sectors, particularly in agriculture, horticulture and commercial forestry production. Pesticide withdrawals through legislation, coupled with resistance development and their impact on plant health, have emerged as key concerns for Scottish plant health stakeholders.  This project quantifies the impacts on Scottish plant health that will arise from pesticide withdrawal scenarios and sets this in the context and time frame of alternative management tools. 

Forestry, Horticulture, Agriculture, Environment | Final Report

Expansion of PHC Online Plant Health Resources

Authors: Joanne Taylor, Katherine Hayden
July 2020

This project has expanded the PHC online Resource Bank for plant health threats to the Natural Environment sector in Scotland to include information sources for the remaining three sectors (Forestry, Agriculture and Horticulture). Information sources for Forestry, Agriculture and Horticulture were compiled and evaluated, and a Knowledge Bank relevant to each sector is now online at the PHC website, creating a comprehensive and unique signposting resource for plant health information with relevance to Scotland.

 

Forestry, Horticulture, Agriculture, Environment | Final Report

Impact of climate change on the spread of pests and diseases in Scotland

Authors: Adam Kleczkowski, Matt Castle, Glyn Jones, Vincent Keenan, Crawford Revie , Oleg Sheremet
June 2020

This project constructed a modelling framework which combined epidemiological and economic modelling.  The modelling framework was used to study predictions of spread and economic impact of pests which are not currently in the UK, including Xylella fastidiosa, Candidatus Liberibacter solanacearum (Zebra chip) and Ips typographus (Eight toothed Spruce Bark Beetle). 

Impact:  A web/desktop application is available to the PHC and Scottish Government to analyse the effects of climate change on the spread and economic impact of new threats. 

Forestry, Horticulture, Agriculture, Environment | Final Report and Policy Document

The use of mobile technology to enhance plant health monitoring and awareness in Scotland

Authors: Sebastian Raubach, Jennie Brierley
August 2019

The aim of the project was to review existing websites and smartphone apps currently available and applied in the plant health sector and to assemble a detailed overview covering the following points:

  • What options are available in terms of mobile software applications for plant health?
  • What is their primary purpose?
  • Who is the target audience (growers, plant health professionals, citizen science, …)?
  • Which plant health sectors do they cover?
  • Are they reliable and accurate?
  • Is information submitted to a central database? If so, how is this information used?
  • Could they be used globally, or are they limited to certain geographic regions?
Agriculture | Final Report and Policy Document

Assessing the potential of the psyllid Trioza anthrisci to vector Liberibacter solanacearum (Lso) in Scotland

Authors: Fiona Highet, Ali Karley
June 2019

The aim of the project was to assess the distribution and population numbers of the psyllid Trioza anthrisci and it’s potential as a vector of ‘Candidatus Liberibacter solanacearum’ (Lso).  The project has allowed the PHC to better understand the distribution and number of T. anthrisci populations in carrot growing areas to better inform assessment of the risk of disease transmission to crops in Scotland. 

Horticulture, Agriculture | Policy Document

Impact on Scottish crops if the molluscicide metaldehyde is withdrawn

Authors: Fiona Burnett, Andy Evans
December 2018

This report sets out estimates for the crop loss and value to Scottish crop production should the molluscicide metaldehyde be withdrawn. This would leave ferric phosphate as the only available chemical control option. Short term losses are negligible as the substitution of ferric phosphate carries no additional treatment costs and has equivalent efficacy. Longer term there is some risk should resistance arise to this single site mode of action active, and ferric phosphate (although of lower mammalian toxicity to metaldehyde) has some environmental impacts of its own.