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.
• A review of possible interventions to include a review of PCN management in other countries to inform the work packages below:-
• Modelling future risks of both G. rostochiensis and G. palida using interventions identified in the review and climate scenarios.
• Grower behaviours and attitudes to interventions, to include input from industry stakeholders.
• An economic analysis of likely impact in Scotland based on a range of possible interventions.
Impact: A clearer understanding of possible control options, economic impacts of available interventions and the likelihood of growers and buyers adopting new resistant varieties, altering rotation practices or any other interventions such that recommendations on best strategies (including statutory controls) can be made.
Impact: This project will contribute to Scottish Government’s preparedness measures for the possible arrival of Xylella fastidiosa by ensuring surveillance monitoring is effective and by identifying the key knowledge gaps for effective surveillance.
Impact: Improved understanding of costs and benefits of pesticide use across Scottish sectors and an impact analysis for the most likely withdrawal scenarios such that key gaps can be identified and their impact quantified in order to inform pesticide policy.
Impact: Easily accessible tool for stakeholders and government plant health officials to assess possible impacts of climate on pests and pathogens in Scotland.
Impact: Improved understanding of concepts and options amongst the Scottish stakeholder community; a basis for gap analysis by the PHC.
Impact: Improved understanding of concepts and options amongst stakeholder community in
Scotland; a basis for gap analysis by PHC.
Impact: Improved risk assessment; better equipped stakeholders and government plant health officials; improved coordination of plant health activities in Scotland.
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.
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
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.
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.
Assessing the potential of the psyllid Trioza anthrisci to vector Liberibacter solanacearum (Lso) in Scotland
The aim of this 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.
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.