Potato Problems? Visit the Plant Health Clinic

Posted 6 August 2004

Potato farmers and growers may be interested to learn more about The Plant Health Clinic at the Crop and Environment Health Centre at Harper Adams University College, Shropshire. The Plant Health Clinic (PHC) was initiated to provide a range of pathology based diagnostic services to potato growers; particularly those in the west of the country where no such service provider is available. The PHC aims to offer the best possible customer service whilst maintaining highly competitive prices. Currently a number of services are available including microscopic and macroscopic disease assessment, virus testing and estimation and species determination of plant parasitic nematodes in soil.

Dr Matthew Back, of the PHC, said: “In the UK, approximately 130-150,000 hectares of potatoes are grown every year with a value of around £500 million. Potatoes are subject to attack from an array of pests and diseases during the growing season and in storage, some of which can cause serious financial losses to growers. By sampling and assessing potato seed or soil prior to use, many of these diseases can be avoided or counteracted with an appropriate crop management strategy.

“Macroscopic disease assessment includes a full inspection of skin based diseases such as powdery scab, black scurf, silver scurf and black dot as well as a damage score, count of rots, pest damage and a record of other internal and external defects. An additional microscopic test can be undertaken to determine the incidence of disease inciting pathogens, not visible with the naked eye.”

He added: “Virus testing involves growing on a sample of 100 tubers for four to six weeks before using ELISA based assays to estimate the incidence of potato leaf roll virus (PLRV) and potato virus Y (PVY). Additional virus (PVYn, PVA, PVX and PVS) may be tested at an additional cost.”

The PHC also undertakes work relating to plant parasitic nematodes. Standard potato cyst nematode counts (PCN) in eggs per gram of soil are offered as well as a specialised molecular diagnostic test for determining the proportions of PCN species. At present work is under way to develop a unique RNA based assay which allows the assessment of viable nematode populations to be estimated. Such a test would be of particular advantage to growers who want to test the viability of PCN cysts following application with the fumigant 1, 3 dichloropropene (1, 3 D).

As well as PCN, the PHC is able to offer counts of ‘free living nematodes’ (FLN) from soil. Free living nematodes consist of a number of ectoparasitic (surface feeding) species, which can cause direct feeding damage or transmit tobacco rattle virus in potatoes (Trichodorids or stubby root nematodes).

Growers wishing to submit samples or obtain further information should contact Dr Matthew Back (Tel: 01952-815361, Fax: 01952-811375, Email: mback@harper-adams.ac.uk).