Potato stocks held by growers at the end of March were 20% higher than the same point last year due to the impact of Covid-19 on consumer demand.
Figures from AHDB show that the stocks of potatoes in Britain totalled 1.19 million tonnes, which is 5 percent above the five-year average.
Drawdown, the rate at which potatoes are delivered from store, was 2 percent down on average between January and March.
David Eudall, head of arable market specialists at AHDB, explained that the figures are from the end of March, so they only include one week of the ‘lockdown effect’.
But the 'big impact' on the sector had been the way the coronavirus pandemic has changed consumer demand, he said.
“From 23 March, the industry saw wholesale closures of fish and chip shops and other foodservice outlets. There are reports of some chip shops reopening across Britain, but sales are likely to be significantly reduced,” Mr Eudall said.
AHDB said it would publish further in-depth reports into the processing and chipping sectors on 7 May, once more data has been analysed.
While growers have been hit by the near-total closure of the foodservice sector, sales of fresh and frozen potatoes in supermarkets rose 28 percent in March, ahead of overall food and drink growth for the period.
Dr Rob Clayton, potatoes strategy director at AHDB, said that the specialist nature of the potatoes used for each part of the market meant some growers could suffer 'large financial losses'.
“With one or two exceptions, a different set of varieties is used to make chips in restaurants from the ones consumers are used to seeing on supermarket shelves.
"If you’ve got a shed full of potatoes that were meant for making French fries, you might currently be unsure whether a year’s worth of work to grow and store them will amount to anything – it’s a stressful situation."
He added: “The wider industry has been meeting to work through what can be done at pace, we hear that supermarkets are taste testing different varieties for example. But this will only apply to a small proportion of what’s in stock.”
Meanwhile, AHDB has released plans for an extended consumer marketing campaign, and a portal to help put the growers and wholesale buyers of potatoes in touch.
The campaign is based on reminding consumers of the versatility and value of potatoes, and how they can be incorporated in many dishes.
A trade portal will be launched next week where wholesale potato buyers and merchants can post requirements for potatoes, and growers can post available stocks.
“The supply and demand profile of our normally well-established market is changing very fast,” said Dr Rob Clayton.
“With one part using stocks quicker than normal, and one with a surplus, the portal should help ensure consumers are able to find top-quality potatoes, which is what we all want.”
Some growers, including Jonathan Papworth and Greg Bliss of Fen Edge Farming, have donated potatoes that were destined for fish and chip shops to food banks.
FareShare, a charity that coordinates the supply of food banks, can now take appropriate bagged potatoes.