Development of a PCN population advisory tool that provides robust advice and management

Potatoes are consumed as part of approximately 10.14 billion meals made at home each year in the UK, which is an average of three/four meals a week for each member of the population (AHDB, 2015). The home-grown supply of retail potatoes accounts for 87% of the market. AHDB Potatoes estimates the UK potato production together with subsequent processing and added value has an annual value of £4.5 - 5.5 billion.
The potato cyst nematodes (PCN) Globodera rostochiensis and G. pallida are important soil pests that cause major economic losses to potato growers. G. pallida is the most prevalent species in the UK and its control is the most problematic. A lack of commercially favoured resistant potato varieties and concerns surrounding the use of chemical control measures have resulted in G. pallida being an intractable problem to farmers both in the UK and in many other countries. Both PCN species live as parasites and must complete the majority of their life-cycle in potato roots. PCN has a complex interaction with its plant host. Juvenile nematodes are microscopic worms that hatch from eggs in the soil upon detecting a host plant growing nearby, then locate and subsequently invade the roots of the host. The nematode migrates inside the root and selects a single root cell that it transforms into a large specialised feeding cell. The nematodes withdraw nutrient from the specialised feeding cell over several weeks. Each plant can harbour many hundreds of nematodes and their feeding has a dramatic, detrimental impact on the growth and yield of the potato crop. The control of PCN is named as a top industry research priority.
The Agricultural and Horticultural Development Board (AHDB) Potatoes is a statutory levy board, funded by the potato industry. AHDB's remit is to equip its levy payers with independent, evidence-based information and tools to grow, become more competitive and sustainable. As part of meeting this remit AHDB Potatoes provides the sector with information regarding PCN. They offer a web based educational tool and decision justifier that can allow a grower to visualise different 'what if' scenarios related to PCN that are relevant to their enterprise and agricultural practices. The advisory tool shows the implications of a grower's actions on the level of PCN infestation and the effect on the predicted yield. This demonstrates that treatment of an infestation is best tackled early when the levels are low, as this is when the use of nematicides has the greatest effect. The effect on yield is based on mathematical predictions.
AHDB appreciate that the PCN advisory tool requires improvement and updating because while offering valuable advice in certain scenarios the model could reflect outcomes more accurately. We propose to collate data from known sources and collect more data where necessary in relation to specific aspects that affect PCN multiplication such as temperature, tolerance of the potato variety to the pest and the emerging control strategies of biofumigation and trap-cropping. The data will be analysed and used to provide mathematical predictions in an improved PCN advisory tool.

The application addresses a specific issue proposed and supported by AHDB Potatoes. Development of a PCN population advisory tool that provides robust management advice will allow growers to make better informed management decisions with respect to their own circumstances. The consequence will be improved long term management of the PCN problem and increased yield for the grower. The potato industry is important to the UK economy and it is therefore vital that PCN does not cause a long-term competitive decline in the UK-based potato production and processing capacity relative to elsewhere with a less severe PCN problem (e.g. France, Poland).