At the carrot technical seminar, ADAS consultant John Birkenshaw said HDC trials had shown it was possible to store washed, graded and polished carrots as late as May. "Taste and sugar levels were preserved but skin finish was inferior to field-stored carrots," he said.
He added that field storage remained the most cost-effective way of storing carrots but, over the 2006/07 winter when the trial took place, rotting levels were high, with only 42 per cent of the crop marketable by May compared with 87 per cent of washed and polished roots from refrigerated storage.
While field storage costs £50/tonne, Birkenshaw calculated that storing washed and polished carrots would cost £74/tonne, and dirty carrots £76/tonne. But using refrigeration could mean that carrot production could move on to heavier soils, if pushed to by climate change. "We're geared up to lifting in winter and you can only do that on sands," he said.
British Carrot Growers' Association chairman Martin Evans said: "Field storage in soil is a relatively new technique to extend the season, but we know we could deliver a better product in that period."