The theme will run strongly through the first day of the prince's three-day tour in Wales. As one of the most prominent supporters of organic food, he will begin his visit to to Wales's biggest agricultural event by meeting with opponents of genetically modified crops.
Fourth and final day of Wales's largest farming event
He is expected to visit a pavilion in the showground at Builth Wells, mid-Wales, where critics are launching a campaign to ban GM crops in Wales.
Senior members of all the main Welsh political parties are backing calls by Friends of the Earth Cymru to ban any further release of GM crops.
FoE Cymru says the National Assembly for Wales would show a commitment to the environment and promote a good image for Welsh agriculture by banning GM crops.
Gordon James of FoE Cymru said: "We are pleased that so many prominent people in Wales have willingly supported our statement calling on the assembly to take action on the issue."
Customers think organic food is too dear
Aside from the issue of organic food, the Prince of Wales will meet with Royal Welsh Agriculture Society President Hugh Thomas and view final judging and presentation of prizes in the Native Beef Breeds Championships.
He will then present the Queen's Cup to the exhibitor of the Champion Welsh Mountain Sheep.
Rural regeneration visit
On leaving the show - at the close of its fourth and final day - he will go on to to visit Llanbadarn Fynydd, a hill-farming community near Newtown, mid Wales, which is becoming well known for its enterprising approach to rural regeneration
He will visit the village shop, filling station and post office, which have been bought and run by the community.