Seed potato disease testing

Potato seed tubers can be affected by many fungal, bacterial and viral pathogens which may adversely influence emergence and crop yield. Some seed-borne diseases also reduce the value of ware crops as a result of blemishing.

NIAB LabTest provides assessment of fungal, bacterial and viral infections of tuber samples. Such assessments enable high quality seed to be identified, highlights potential problems ahead of planting and supports development of targeted IPM strategies. Virus assessments are also provided for foliage; virus testing in the mother crop can provide a valuable part of risk assessment for seed growers.

NIAB LabTest also offers identification/confirmation testing for blackleg, powdery scab and common scab diseases. Plant Clinic evaluation is also available for situations where the problem cannot be readily identified in the field/store.

Available tests, packages and prices

For more details about the laboratory tests click on the links below

All samples must be accompanied by a completed order form

Submission form

NIAB recommends a sample size of 100 tubers for visual disease assessments and germination tests and 110 tubers for virus tests. Where all three tests are to be carried out for the same stock, please submit three SEPARATE bags, each containing the right number of tubers for each test; total 310.


For all assessments, obtaining a representative sample for analysis is essential. While it is not realistic to assess every single tuber from a field or seed stock, sampling strategies need to be considered carefully depending on a range of factors, including the target disease, to ensure that samples are representative of whole seed stocks to provide reliable information for growers. 

The general advice on sampling makes a number of important assumptions, which are, primarily, that the infected tubers are distributed evenly in the field or stock, and that tubers are sampled randomly. Testing different samples from the same seed stock or field is expected to give a range of results since no crop is perfectly uniform. Statistically, the results will lie within a specific interval around a mean and which can be used to predict the value of the sampled stock with a certain percentage confidence. This interval is known as the confidence interval.  More variable crops will have a large confidence interval, since there is less certainty about the characteristics of an individual tuber from the crop, and more uniform crops will have a small confidence interval. The accuracy of any estimation can be improved by increasing the sample size. In addition, the choice of the size of sample to be tested will need to be balanced by practical factors, such as cost, available facilities, labour, logistics of handling samples, seed stock size, etc.

If customers wish to discuss sampling strategies for their particular circumstances - contact Elizabeth Stockdale.