But it also found that it is riskier, particularly in bad scab years such as 2008, and that because high-cost selective insecticides have to be used, pest control is more expensive than that of conventional production.
Details of the completed project were given by East Malling Research (EMR) plant pathologist Dr Angela Berrie at the British Independent Fruit Growers Association's (BIFGA) 23rd annual Technical Day on 12 January.
She said the most important aspect of zero-residue management was good pest and disease monitoring, with problems identified early and appropriate action taken quickly.
"Consumers want perfect apples, varieties they have heard of and no pesticide residues - that's a pretty tall order," she said. "However, because zero-residue management is more risky, growers will need incentives (to adopt it). Consumers will have to pay more for the fruit, but will they be willing to do so?"
The Defra, Horticultural Development Company and Worldwide Fruit-funded project was carried out for the first few years at EMR and then in commercial orchards in Kent and Gloucestershire.
The preferred option for producing residue-free fruit was to avoid the use of conventional pesticides after petal fall and then combat pest and disease problems in ways that removed pesticide residues. A riskier alternative would have been to use conventional pesticides and extend their harvest intervals.
The post-harvest or dormant period features of the zero-residue system were DMI fungicide for late mildew and scab control, pre-leaf fall urea to eliminate overwintering scab, leaf-fall copper or Folicur for canker, pre-bud burst copper for scab control, a post-harvest aphicide and a winter application of a nematode product.
During the petal fall to harvest period, the only fungicide used was low-dose sulphur against mildew, while granulosis virus or Bacillus thuringiensis were relied on for pest control.
"There were no residues in apples produced under the zero-residue system and those in the conventionally produced fruit were below the maximum residue limit," said Berrie. "The problem is that increasingly accurate equipment can detect lower and lower residues (and so what is not detectable now may be in the future)."