Tesco Ireland, the self-styled "biggest buyer of Irish food in world", is staking its claim, literally, in the fields.

Travellers in the countryside over the next few months are going to see some funny signs rising out of Irish fields.

They will not be put there by the anti-GMO lobby targeting possible areas of contamination, but by Tesco Ireland, telling you where it is sourcing its food products.

The signs say: "This crop is being grown for Tesco Ireland, committed to working with Irish growers.".

The Rathcoole, Co Wicklow, potato farm of brothers John and Paul Brady is one of the first of 68 fields that will grow a Tesco sign over the coming months. "Our land has upwards of 10,000 cars passing by daily and most of these people would never realise that the potatoes we grow end up on the shelves of their local Tesco. It's a great idea and we are delighted to be part of it," the two brothers said.

Tesco claims it is paying £835 million each year to Irish companies for products stocked in its stores in Ireland and Britain. A Tesco spokesperson would not say how much of that was accounted for by food products, but he said that Tesco was the first supermarket chain to highlight its commitment to the Irish grower base and to raise an awareness of its involvement with Irish agriculture.

Mr Gary McCormick, produce technical development manager for the chain in Ireland, explained that the initiative was being driven by the growers themselves. "There will be 68 signs in total, nationwide, from Wexford to Kerry to Louth and the growers are delighted that passers-by will now know where the vegetables they see will end up."