Potato Cyst Nematodes have been known to occur in the UK for nearly one hundred years.

They are the most problematic pest of potatoes and can cause a severe yield loss.

Max sample size up to 10 acres. Bags can be supplied and posted out.

• The past history of the field

• Last year's potatoes grown

• Variety of potato grown

• Any problems in previous potato crop relating to PCN

• Any use of nematicide

• Presence of Deadly Nightshade


At least 30 cores are needed however small the area to be sampled.

All results of PCN analysis must be interpreted in conjunction with:

The minimum sample weight for PCN analysis is 1kg and for PCN/LOAM analysis is 1.5kg.

The preferred sample weight for PCN analysis is 1.5kg and for PCN/LOAM analysis is 2kg.

PCN sampling requirements

checklist icon Download the field form a Microscope

Potato Cyst Nematode Analysis

No cyst found in the sample analysed. Due to the nature of PCN distribution, an absence in the sample cannot guarantee that no PCN is present in the field.


Low numbers of eggs found in the sample. PCN is present. Due to distribution absence of PCN related problems cannot be guaranteed.


Moderate numbers of eggs found. There may be visible signs of PCN present and a loss of yield if cropped with potatoes next season.


High numbers of eggs found. There is likely to be a severe yield loss.


Empty cysts were found in the sample. PCN has been a problem in the past and no guarantee can be made that all the remaining cysts are dead.

PCN Result Categories

Nil Count:




Low (1-10 eggs per gram):




Moderate (11-60 eggs per gram):




High (60+ eggs per gram):



Beware of Dead Cyst Count:

Potato Cyst Nematodes are not evenly distributed across a field so some parts of the field may have higher than average numbers present resulting in 'hot spots'. Some areas of a field may have low counts, so the results shown refer only to the sample received in the laboratory.


It is essential to follow the recognised sampling procedure as laid down by the Ministry of Agriculture. Sample guidelines are available on request from the laboratory.