The three retailers had all invested heavily in TV campaigns urging shoppers to buy English apples, according to Adrian Barlow, chief executive of English Apples & Pears.
Two months into this season, The Co-op's share of the English dessert apple market is up almost two percentage points to 6.9%, while Sainsbury's has jumped from 25% to 26.2% and Morrisons from 15% to 15.8%.
Asda had also done good work promoting British food generally, while M&S and Somerfield had been backing English apples in the media, Barlow added.
In-store promotional activity had been focused on Cox and Gala as consumers were made aware that the UK top fruit season had begun, Barlow said.
"But it's important that promotional activity doesn't go on too long and that prices are restored to levels of profitability that justify the huge levels of investment being made by growers," he added.
Cox is still the biggest-selling English dessert apple but Barlow predicted the volumes produced were likely to decrease by 5% to 10% over the next few years, and that Gala would become the biggest seller within four years. Many younger consumers, who preferred crisper, juicier apples, were favouring Gala and Braeburn over Cox, he claimed.
New varieties such as Rubens, Jazz, Cameo and Kanzi were all being grown in record volumes this year, and were expected to continue to increase their share, he said.
However, Barlow raised concerns that this year's Bramley crop - which is 15% larger than last season's - might still prove insufficient to meet the expected uplift in demand that will accompany next year's Bramley bicentenary celebrations.
"I would have preferred a 25% to 30% larger crop," he said. "I fear we won't be able to meet the full demand."