Farmer fined pounds 220,000 for crop spraying.
Colin Boswell, of Mersley Farms in Newchurch on the Isle of Wight, was one of Britain's biggest sweetcorn producers and sold to Tesco, Sainsbury's, Marks & Spencer and other supermarkets.
But in June this year he admitted 11 breaches of health and safety law after an investigation by the Health and Safety Executive.
At Portsmouth Crown Court yesterday the 47-year-old was fined pounds 20,000 for each of the breaches and was ordered to pay costs of pounds 16,862.
Judge David Selwood said that if the fines were not paid within 14 days then a three-year prison sentence could be imposed.
He said: "They are serious offences involving a course of conduct prolonged for a period of two years, demonstrating a disregard for health and safety."
Portsmouth Crown Court heard that Liquid Gaucho, Aztec and Capsolane were sprayed on crops at the 850-acre farm. None has UK approval for such use.
Mr Oba Nsugbe, for the Health and Safety Executive, said the organophosphate pesticide Metaphor had been used before it was licensed for use in Britain.
He said a "cocktail of pesticides" had been applied to the sweetcorn which was then sold for human consumption.
Boswell had previously admitted breaching the Control of Substances Hazardous to Health Regulations 1994, the Management of Health and Safety at Work Regulations 1992 and the Control of Pesticides Regulations 1986.
The charges relate to the sweetcorn-growing seasons of 1997 and 1998.
Mr Nsugbe said there had been a reckless disregard for the health of employees and said the records of pesticide-spraying at the farm had not shown the use of the illegal chemicals.
The court heard that an aphid infestation in 1997 had threatened to wreck 40 per cent of the crop on the 900-acre farm, which would have lost Boswell about pounds 180,000 in profit.
The nerve toxin Metaphor was used and employees were sent in to pick the crop with bare hands just two or three days later.
By 1998, Metaphor was unavailable so Capsolane, Aztec and Liquid Gaucho were used on the crops.
The "systematic abuse of pesticides" only came to light when two former employees, Leonard Oatley and Peter Kingswell, decided to act as whistle-blowers, Mr Nsugbe said.
Workers had complained of headaches and skin rashes after the harvesting and Mr Nsugbe said there was little doubt that the sweetcorn had entered the human food chain.
Reading from a report by toxicology experts, Mr Nsugbe said the spraying posed an unacceptable risk to growers and pickers.
In a worst-case scenario, "undesirable levels of pesticide residues" could have been left on the corn when it went to the supermarkets, he said, but the risk to consumers was not thought to be significant.
He said serious health effects were not anticipated for consumers, but added that the long-term health risks of exposure to organophosphates was still not known.
Mr Kevin de Haan, in mitigation, said Boswell had not known the full extent of the pesticide misuse but had always told police: "The buck stops with me."
He said Boswell was a pillar of the Isle of Wight community, an adviser to the Ministry of Agriculture, Fisheries and Food and a regional delegate of the National Farmers' Union.
But since the HSE investigation the business had failed and Boswell now had an overdraft of pounds 1.1 million, Mr de Haan said.