Thousands expected to attendpublished at 09:06 British Summer Time 8 June 2023
The Rural Cornwall Agricultural Association says the show, which runs until Saturday, is aimed at promoting innovation and the future of farming in the county.
Dating back to 1793, the association says the show gives a platform for farmers, businesses and other local people to showcase their work in the industry.
About 120,000 people are expected to attend over the three days.