Richard Hirst, chairman of the NFU board for horticulture, said: "Government immigration policies limit numbers and this year, like the last, members lost crops worth between £15m and £20m up to the end of August and there's still two months to go."
At the show, held in London's Docklands, he said: "Good food is being left in the field. If people can't get the labour they will reduce the amount of land for growing."
This was "perverse", he said, adding that regulation such as the water-framework and imminent soil-protection directorates, set-aside rules and the onus on organic growing would curtail production when more was needed. "We are being asked to provide 21st-century solutions with 19th-century methods."
Meanwhile, the Fresh Produce Consortium warned that new pesticide rules would increase food prices 100 per cent, while the NFU said such laws would turn every scrap of British countryside into a country park for wildflowers.
The consortium called for a "comprehensive impact assessment based on scientific risks" on the plans and urged its members and other growers to lobby members of the European Parliament.
Communications manager Sian Thomas said the proposals, facing a vote this month, could double food prices. Hirst claimed they would "tie growers' arms and legs behind their backs". He said: "The countryside will become a country park for wild flowers, which is fine as long as I'm paid for it."
Lack of investment is starving research and development so badly that, within a few years, Britain will have only one laboratory site left, the NFU's Richard Hirst told delegates at the World Fruit & Vegetable Show last week in London.
"There is no government incentive for production horticulture and agriculture," said Hirst. "Defra service targets focus on climate change and the environment. Why don't they have anything to do with productive horticulture and agriculture?"
Present funding of £4.5m came from levies from the grower community, which had to be spread over research into 300 crop varieties. This was a pitifully small amount, he said. "Within two or three years we could have only one site left. Yet the Government wants us to look at how we deal with soil, the environment and pesticides."