Corporate social responsibility will be the next big differentiator in the marketplace, he said. "You have to be in some sort of supply chain these days and that includes NGOs and charities that are very good at what they do and can cause you headaches," he added.
He said that persistently high oil prices for the next 12 months will have an impact on horticulture, and asked: "Can you farm less intensively?" But he added: "Turning our back on genetic modification is a missed opportunity."
Further ahead, while the UK won't be immune to climate change, "compared with South Africa or North and South America, the UK will undergo less change and will still be a pretty good place to farm and produce food", Giles forecast.
Britain will never be a big player internationally so should concentrate on its home market, he concluded. "World brassica production is dominated by China and India, and is gently falling," he added.
"The UK has always been about 90 per cent self-sufficient in cabbage and 50-60 per cent in cauliflower. Replacing imports is more realistic than trying to export, although it's hard to get the last 10 per cent."
A full report on the conference will be published next week.