Warning over virulent strain of blight

Published on Monday 28 April 2008 21:11

FARMERS have learned how to deal with potato blight in the 160 years since Ireland's great famine, and the advent of modern agro-chemicals has done much to cut crop losses.

However, the disease, which is caused by the fungus Phytophthora infestans, has mutated over the years and the current strain is especially virulent.

Rob Clayton of the Potato Council, the organisation funded by growers, said: "We're now dealing with a different type of blight. We are expecting an early start to the season and control measures may have to remain tight. Growers should be deciding their control strategy around how this type behaves in the field. This year, more than ever, best practice really does mean best practice."

Blight is the number-one potato disease, and while Scottish crops tend to be less susceptible because of a generally cooler and less humid climate than in England, losses can still be considerable.

Growers throughout the UK are estimated to spend at least 20 million each year on blight control.

Clayton recommends constant vigilance of all potato crops from emergence early next month and advises growers to discuss spraying programmes with an agronomist. Growers might be well advised to vary the mix of chemicals throughout the season.

The Potato Council runs a combined "Fight Against Blight" and "Blightwatch" service to provide early warnings of disease outbreaks.

Clayton said: "It is vital that growers make good use of these services. This is now an integral part of Britain's defence in the battle against blight, and the 350 'blight scouts' play a crucial role in supplying samples and identifying actual outbreaks."