Farmers are being warned to help prevent a potential potato famine after the emergence of a devastating crop disease.

The first case of ring rot, which has been labelled "potato foot-and-mouth," was discovered by Defra officials on a farm in Wales.

There are concerns the contaminated seed could have been delivered elsewhere.

More than 1,000 hectares are used to grow potatoes at farms across East and West Sussex, generating an estimated £7 million in revenue each year.

Sussex farmers have been put on their guard as Defra admitted officials were unsure how many might have bought the contaminated produce from a supplier in Holland.

The bacterium c lavibacter michiganensis sepedonicus, which causes ring rot, was confirmed in a sample of potatoes produced from Dutch seed potatoes.

It has been established that the farm sold produce to three sites in the Scilly Isles and Cornwall.

A Defra spokeswoman said: "We have managed to keep this disease out of the country for a long time but lots of places in Europe already have it.

"If the disease goes unchecked and gets into the soil it becomes a problem for years afterwards.

"The farm where it has been found will not be able to grow potatoes for a number of years."

The disease appears as black rings within the potato, causing the vegetable to rot.

It is not thought to pose any risk to human health.

Sussex farmers expressed concern about the findings but insisted their seeds were strictly examined for safety.

Andrew Monnington, of Sidlesham, near Chichester, has about 50 hectares of potatoes.

He said: "The seed I use has gone through many quality standard checks and is checked while it is growing.

"Every load I get is examined by an agronomist before I pay for it as I don't want to buy sub-standard seed.

"This is why British seed is seen as some of the best in the world."

Despite the case in Wales, Mr Monnington is still confident enough with the potato industry's inspection system.

He said: "I would like to think the system is working. Ring rot is endemic on the Continent and not here so I think it is working."

Industry experts believe the ring rot impact will not be as catastrophic as the foot-and-mouth epidemic.

Dr Mike Storey, of the British Potato Council, said farmers had little to worry about if they took the right precautions.

He said: "Ring rot would be a major risk to the industry if it was allowed to spread but the comparison some people are making with foot-and-mouth is completely inaccurate.

Defra has moved very quickly in this case to isolate the affected farm and is tracking stock movement from the farm.

"The best thing farmers can do to protect themselves is to look at the source of the seed they are buying and make sure they get it from a ring rot-free area."

Wednesday November 19, 2003