Tomato Brown Rugose Fruit Virus (ToBRFV) has already reached France, with a case confirmed in Finistère just days after a warning from food security agency Anses.
It warned amateur and professional gardeners of the danger of a disease that has spread round the world in just four years – and which has no cure.
Anses said it is not dangerous to humans but could be spread “by infected seeds, plants and fruits, as well as by simple contact. It survives for a long time without losing its infectious power, and has no treatment or any resistant variety”.
The Breton case is with a tomato producer, though it was expected to be spread in family potager gardens because of proximity to kitchens, people coming and going, and seeds being bought online.
The agriculture ministry said the plants would be pulled out and incinerated, and the site disinfected to stop spread.
Brittany is France’s main tomato-growing area, producing 30% of the total, and French households are keen customers, buying 14kg a year.
The virus spreads easily between plants and can also be spread by touching surfaces, such as garden tools, gloves or even tiles.
Anses said it would have a “significant potential impact on crops” with up to 100% loss.
Infected plants will have discoloured leaves and dark or brown marks on flowers, while infected tomatoes, peppers or chilli peppers will not grow properly, may be seriously deformed and discoloured, with a rough surface texture – making them impossible to sell and unpleasant to eat.
If plants do appear infected, the only way to stop the spread is to rip the plant out at the root and destroy it by burning.
German authorities managed to eradicate the first case there by tearing up and incinerating the plants and disinfecting soil.
Philippe Reignault, Anses dir-ector of vegetable health, said: “It is better to take maximum precaution.
Even with a risk of wrong identification, eradicate the plants and burn them.”
France grows 520,500 tonnes of tomatoes a year but its production pales alongside that of Italy, the No1 European grower at six million tonnes.
Spain, Greece, Portugal and the Netherlands follow, and the virus is present in each.