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Plant Health: weed, pest & disease management

PCN (Potato Cyst Nematode)

30 January 2019

Photography: HAU

Potato cyst nematode is the most important potato pest in the UK and has the potential to cause substantial yield losses. 

There are two species of PCN, Globodera rostochiensis and Globodera pallida. G. pallida has become widespread due to its prolonged hatching period and the selection pressure created by the cultivation of many varieties that are resistant to G. rostochiensis but susceptible to G. pallida.

PCN - the national picture: VIDEO October 2018

PCN Grower Guide - Updated November 2018

The publication of the PCN grower guide follows a literature review by a group of nematologists led by Sue Hockland and including Dr Tom Prior of Fera, Dr Kim Davie and Dr Jon Pickup of SASA, Dr Vivian Blok and Prof John Jones of the James Hutton Institute and Dr Matt Back and Dr Ivan Grove of Harper Adams University.  

The integrated approach in the guide recommends the use of a range of control measures to reduce the PCN population at the time of planting.

These include hygiene, clean seed, control of volunteers, rotation length, trap crops, biofumigants, nematicides and variety selection.

If you would like to order a hard copy of the publication please click here and send an email with your name, phone number, address and the name of your levy paying business or you can phone 024 7669 2051.

Sampling and laboratory testing - download the guide

Sampling and lab testing are vital, as, at low levels of infestation, no symptoms are seen in the field.

This document provides a step-by-step guide to the sampling and testing process. If you have any further questions please contact your agronomist/advisor or your AHDB Knowledge Exchange Manager.

It is aimed at growers who either have not sampled for PCN before, or who would like to know the basics and best practice methods to ensure the best possible chance of finding a PCN infestation is achieved. Due to the irrregular way PCN spreads and inhabbits fields, a robust sampling technique is vital.

More information about the drafting of this guide, and the research that contributed to it can be found here

To download this guide please click here

More resources

AHDB Potatoes PCN Pallida calculator is our web based educational tool or decision justifier which can allow you to play out and visualise different ‘what if’ scenarios relevant to your enterprise. 

While the tool does not offer advice on what you should do, it will show you the implications of your actions on the level of pallida infestation and the effect on your predicted yield. This will demonstrate 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. If the infestation is very low, the yield reduction can be so low as to be unnoticeable when a crop is commercially harvested. This can lead to a false economy and the thinking that PCN can be ignored as there was no visible drop in the expected yield. The effect on the Pf or final population after harvest could create issues for subsequent potato crops.

PCN control requires an integrated approach including choosing the correct variety and working within sustainable rotations. However, nematicides are crucial to the control of this pest. AHDB Potatoes supports the Nematicide Stewardship programme (NSP) to ensure sustainable, safe and effective use of these pesticides. 

Latest technical information and tools 

AHDB Potatoes PCN research projects

Links to other organisations and publications