With potato crops plagued by blight following the wettest summer on record, the UK’s commercial potato growers have blamed “allotment amateurs” for making a bad situation worse.

Allotments and gardens represent a very small total area of potato cultivation compared with the 160,000 hectares in commercial production.

However, small plots were responsible for a “disproportionate amount of overall blight pressure” in warm, wet seasons such as 2012, claimed Potato Council corporate affairs manager Maria Ball.

Potato crops are prone to ‘late blight’, the spread of which is airborne and relies on periods of warm, wet weather, known as ‘Smith periods’. This year saw the highest number of Smith periods since monitoring began in 2003 - a total of 10,069 compared with 4,441 in 2011.

As well as “a lack of understanding of what late blight is, and how small infections can have far-reaching effects on commercial crops”, Ball said there was also “a lack of effective control available to allotment holders.

Potato Council chairman Allan Stevenson added: “People should be encouraged to grow their own vegetables to learn about the origins of their food, but the blight risk is real, and it would be preferable if people bought healthy, well-produced potatoes from their retailer, rather than grow their own.”

The Potato Council has been working with major horticultural institutions including The Royal Horticultural Society, Garden Organic and the National Society of Allotment and Leisure Gardeners to produce a factsheet to give advice and guidance for smaller growers.

The Council has also recruited ‘blight monitors’ to check on late blight development in commercial crops as well as allotment areas.