The Prince of Wales says the UK will be in a very bad way if links between family farms and the management of landscape are lost.

Speaking on his annual summer tour of Wales, Prince Charles insisted that family run units were vital for the survival of rural communities, and for the defence of the environment, culture and the Welsh language.

His Farmers Marketing Initiative was committed to fostering projects that adopted a "co-ordinated and integrated approach" to sustaining traditional farms throughout the UK.

He praised the development of Mynyddoedd Cambrian Mountains partnership, which his initiative had part-funded, and launched the partnership's new brand logo.

Based on one of his own watercolours of the Cambrian Mountains, the logo will appear first on lamb produced by 15 farmer members of a lamb group that started selling last September.

The Prince announced that, after a successful pilot trading period supplying the Co-operative Group's Welsh stores, the farmers had secured a premium price contract to supply up to 400 lambs a week weighing 12 to 18kg for its Truly Irresistible range nationwide.

"The Co-op has even made a contribution to the initial costs of developing the wider Cambrian Mountains partnership and there has been enormous pro-bono help from many other individuals and organisation."

The partnership included Ceredigion, Powys and Carmarthenshire local authorities, the Countryside Council for Wales and the Welsh Assembly Government, and a food marketing group had been established.

"The Initiative will promote rural enterprise and add value to local products and services," Prince Charles said.

He would do all he could to support those who farmed in and cared for mid Wales, which he described as "a very precious part of Britain".

His tour included a visit to Tyllywd Farm at Cwmystwyth, located in the heart of the initiative's operating areas, to meet James Raw and his wife Clare with other farmers who will supply lamb to the Co-op Group.

Gareth Rowlands, the founder of Rachel's Dairy who chairs the initiative's food marketing group, said: "This is a once in a lifetime opportunity for local food producers and offers a unique trading advantage. His Royal Highness has been very inspiring, generous and hands on."

Later at a reception staged at Llyswen near Brecon, Prince Charles saw how the new logo would look on the range of foods and drinks produced in the Cambrian Mountains.