Fruit and vegetable prices are not actually falling overall, but they are rising far more slowly than they have been, with the month-on-month price change dropping from 2% last month to 0.4%.

More importantly, six of the twelve basket items fell month-on-month and only four items increased. In fact had grapes, one of the most expensive items in the selection, not had a seasonal price rise, the overall basket price would have been slightly down compared with last month.

Growers have warned against reading too much into this month's drop in carrot and onion prices, however. Both were among the items to have grown most in price since last year.

Monthly price falls had more to do with supermarket price pressure than commodity prices, as growers had seen cost hikes and lower yields, said Martin Evans, chair of the British Carrot Growers Association.

"We've got a weather pattern that is very fickle and the reports are we've probably got 85% to 90% of our normal crop," he said.

He also warned that costs had often risen above retail prices.

"Straw, which is used to insulate beds, is 400% more expensive and producers face other increased costs such as the price of land," he added.

Evans said growers needed a lot more than the 18% year-on-year price growth of carrots.

The wet weather that blighted UK wheat farmers benefited the onion crop, leading to higher yields and a bigger crop despite no change in the acreage planted. Holland, which exports 95% of its onion crop, also had a good harvest, leading to oversupply.

However, one grower cautioned that the proportion of this mammoth harvest that was class one quality was likely to be down.

"I suspect there has actually been a slight drop in quality because of the weather," he said. "Not much of the Holland crop is suitable to be sold whole in the UK.

"But because there is so much lower-grade product on the market, the price of onions used as ingredients has gone through the floor, which is being used to put pressure on the class one price."

He added that retailers had passed on very little of the 16.7%

retail price hike to growers and packers, despite there being a significant increase in costs.

"The oil price might have fallen, but it's come a bit too late," he said. "Planting is when we use the most oil, and next year's cereals crops are already planted. Fertiliser prices are still going up, not down, and now OPEC has cut oil production it's possible that oil prices will shoot back up again."

Tests are still being carried out to establish the quality of the harvest of many of this year's crops, and until these results are in it is extremely difficult to predict the future prices of fresh produce lines.

Given that falling oil prices came too late for this year's UK harvests, growers and suppliers caution against expecting prices to fall rapidly.

But with abundant EU harvests in many key crops, and falling petrol prices impacting distribution costs, retailers and consumers can safely expect that price reductions will come.