Vegetable yields have fallen by as much as 50 per cent in some parts of the UK, following a year of extreme weather events.

Farmers have warned of the likelihood of shortages of major crops including potatoes, onions, carrots, leeks, parsnips, cabbages and Brussels sprouts, with consumers and retailers expected to see biggest impacts in the new year.

The year began with the “Beast from the East”, which brought freezing weather to the UK in February, followed by an unusually wet spring that delayed planting. Then a record-breaking summer heatwave took its toll on growing crops.

British Growers Association chief executive Jack Ward said the conditions were “absolutely the antithesis of what a plant needs to grow properly”, and said the industry was looking at an overall drop in yields of about 20 per cent.

But among certain producers the crop shortfall is much worse.

James Pearson, of Suffolk Produce, which grows about 10 per cent of the UK’s onions, and is also a major supplier of potatoes, carrots and parsnips, told The Independent their farms have seen yields fall by 50 per cent for onions, and by 20-30 per cent for potatoes.

He said: “The weather being so hot this summer has also caused a number of quality issues. So there are increased levels of bacteria.

“When crops were coming in we stuck a temperature probe into them and some were reading 40C.”

He added: “The stress this has put on the crops has not really been seen before and nobody really knows how well things are going to store.”