Blight Check detects the blight fungus at the first sign of black spots on tomatoes and potatoes.

Wyevale gardening buyer Sophie Gehin said: “With the summer off to a wet start in many parts of the country, the risk of blight is increasing. Early detection is important for control measures to be effective.”

Blight Check was launched at Glee in 2008. The test gives a “yes/no” result in three to five minutes.