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.
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sets out estimates for the crop loss and value to Scottish crop production should the molluscicide metaldehyde be withdrawn.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.