When Russia banned imports of Polish apples in July, politicians and the public laughed off the move by posing with the forbidden fruit on Twitter. Everyone from the head of the national security bureau to TV presenters posted gleeful photos, making the "Eat apples to annoy Putin" campaign a social media hit.

Six weeks later, after the Kremlin extended its ban to all European fresh produce, from Greek peaches to German gherkins and Lithuanian cauliflowers, eating apples as a political statement is wearing thin. "In the beginning there was a slight growth in consumption, but now it has gone back to normal," says Jolanta Kazimierska, head of the Polish Fruit Union.

Last year Poland sold €840m (£670m) of produce to Russia, including a quarter of all its apples – 1m tonnes of golden delicious, gala, champion and others. Now the trees are heavy with unsold fruit, leaving some growers on the brink of bankruptcy, according to Kazimierska. "We are just praying that this situation improves because if it does not, we are facing real disaster."

Prices have fallen to 0.9 zlotys (17p) per kilo, meaning the farmer barely recoups the cost of production, she said. But the full extent of the damage will only become clear at the end of the month when growers harvest all the apples grown for the Russian market.

Fruit and vegetable farmers have been among the first to lose out from Russia's tit-for-tat sanctions. Almost one third of Europe's fruit and vegetables were sold to Russia and the ban has meant prices paid to some growers have fallen by 80%, according to Copa Cogeca, the European farmers' lobby group.

In theory, European growers should be able to fill the gaps in world markets: if Russia for example buys more apples from South Africa, leaving Chinese buyers short, Poland can jump in.

But in reality a lot of good fruit will spoil on the tree before deals can be done. "We are trying to go to China and other Asian states, but it is a long-term process," said Kazimierska

At the height of summer, several million kilos of Greek peaches and strawberries rotted in lorries that had been turned back at the Russian border. Now as the leaves turn golden, millions of autumn fruits are decaying in the orchard.

Ad Klaassen, secretary general of the Fresh Produce Centre in the Netherlands – one of the countries hardest hit by the Russian ban- said 900 hectares (2220 acres) of Dutch orchards were likely to go unpicked, because it was not worth the cost of harvesting.

The situation is especially tough for Dutch pear growers, with prices 50% lower than last year. Klaassen says the price of vegetables has recovered after an initial drop, but he fears tomatoes, peppers, cucumbers and aubergines will plummet in value when a new batch is harvested from Dutch greenhouses early next year.

With some prices falling to record lows, EU authorities in Brussels came up with a €125m fund to pay farmers to reduce supply, either by turning their crop into compost, letting it rot, or donating fruit to schools and hospitals. More than €82m was allocated for apples and pears alone. But last week the European commission suspended the scheme, after being flooded with what officials deemed as dubious claims for compensation.

Poland alone asked for €145m, including claims for some vegetables that are barely more than seeds. "In one member state there has been a lot of enthusiasm for the scheme," said a commission source. "[The claims] are not entirely realistic and they haven't really read the rules."

Stricter rules are expected to come into force early next week, [from 22 September] meaning no country can claim more than the value of produce they previously exported to Russia. But demands for further compensation are building. With Spain pleading for the scheme to be opened to citrus fruits and Romania lobbying for onions, the commission is also battling member states who want to raid the non-farm part of the EU budget – worth €84bn in 2014 – for emergency funds.

The commission, a civil service with political leaders, opposes the move. A spokesperson said: "member states wanted the 2014 – 2020 EU budget radically cut. They got that, therefore there are limits to what the EU budget can do." He noted there were also calls for extra funds to help Ukrainian civilians, Iraqi and Syrian refugees, tackle Ebola, as well as aid EU farmers.

British fruit growers have so far been largely isolated from the problem, because they exported very little fruit to Russia, but they could lose out if the market is flooded by cheap Polish apples and Dutch pears.

Prices on wholesale markets – where street traders and small shops source their apples – have already fallen, but the big supermarkets, which sell 85% of the nation's apples and pears, have long-term contracts that cannot be switched quickly.

Adrian Barlow, chief executive of the trade body English Apples and Pears, thinks supermarkets will not risk a consumer backlash by buying up cheap apples from the continent, just as native varieties, such as cox and royal gala, are arriving on the shelves.

But he is concerned that depressed prices could undermine UK growers in the long run. Sales of English apples have been rising, after a long period when local fruit fell out of favour and consumers got a taste for France's Golden Delicious and New Zealand's Pink Lady varieties.

"There is a long-term effect because the returns to growers are adversely affected. That encourages some people to cut corners – not in this country, but overseas – and because of that we are not going to see the continued revival of the English apple market."

Fallen fruit

Price falls across the EU in late August compared to average prices for previous three growing seasons:

Apples – 20%

Pears – 50%

Peaches – 40%

Carrots – 8%

Cauliflowers – 32%

Peppers – 34%

Source: Guardian caluculations based on European commission data