A six-year Horticultural Development Council (HDC) and Defra-funded project has shown that producing zero-residue apples that satisfy supermarket demands without compromising quality is achievable.

The trials were carried out at East Malling Research (EMR), and on two Cox and two Gala orchards on farms in Kent. Dr Angela Berries, who ran the project with EMR colleague Dr Jerry Cross, told the British Independent Fruit Growers Association’s (BIFGA) 20th annual technical day at Lamberhurst, Kent, that rigorous pest and disease monitoring is essential for success.

“You must know what’s there, especially scab during blossom and petal fall,” she stressed. “If it’s a problem at these stages, it is not wise to proceed with the [recommended] low-dose sulphur programme for the rest of the season."

Normal commercial spray programmes were used from bud burst to petal fall, the most important period for the control of scab and early pests like winter moth. Then from petal fall to harvest, minimal or nil-residue products like low dose sulphur were applied.

A conventional approach was used again after harvest, during the autumn and winter, with the main aim of minimising overwintering scab and canker inoculum. In addition, cankered and mildewed (primaries) shoots were removed during winter pruning, and a pre-bud burst copper spray was applied against scab and canker.

But West Malling grower Peter Checkley, who was involved in the project, said the big problem is that the supermarkets paid him no premium for the 1,000 bins of zero-residue fruit he produced.

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