Jan Cienski in Ilawa, Poland -

Russia's embargo against food imports from the EU is causing pain for Polish producers, especially apple growers, for whom Russia is the leading export market, but there are gains as well, as Russian shoppers flock across the border.

The principal beneficiaries are shops in north-east Poland. They are seeing a marked increase in Russian customers from Kaliningrad, the Russian enclave on the Baltic Sea, tucked between Poland and Lithuania. 

Border officials say that car traffic jumped after the August 7 ban. The Polish Press Agency reports that in the week prior to the embargo, just under 6,000 Russian cars a day were crossing into Poland. Since, the embargo traffic has jumped by around 10%.

"After the imposition of the embargo, we have to count on an increase in trips to Poland by people from Kaliningrad," Tadeusz Baryla of the Centre for Eastern Research in Olsztyn told the newswire. "The situation on the market [in the Russian enclave] is going to worsen," he adds in reference to Russia's traditional struggles with inflation, "so the only possibility to buy cheaper goods will be shopping trips to Poland."

Rising food prices in Kaliningrad - as reported by the Polish press at least - only threaten to extend the advantages enjoyed by the Polish shops. Before the embargo, Polish food was already about 40% cheaper, and the difference is expected to grow. About two thirds of the enclave's food is imported.

The 1m or so population of Kaliningrad's has had easier access to Lithuania and Poland for the last couple of years. Almost a quarter of a million have now filled out paperwork allowing them to travel to the neighbouring EU regions without a visa. The result has been a flood of Russian shoppers besieging discount food retailers and shopping malls across northern Poland. 

Poles tend to travel in the opposite direction to buy cheap petrol and cigarettes. The visa waiver programme has not been affected by the rising tensions between the EU and the Russian government, with Poland and Lithuania at the forefront of those calling for a hardline approach to Moscow's alleged support for separatists in east Ukraine.

The Russian embargo is also reportedly wreaking havoc on Kaliningrad's food production industry. The region has several meat processing plants, mainly supplied by Polish pork, but imports of the meat have been banned for most of this year by the Russian veterinary service. There are also fish processing plants that rely on Norwegian salmon, which is also affected by the Russian ban.