The first crop of pesticide-free vegetables grown in sealed, computer-controlled tunnels is due to appear in UK supermarkets next month.
Unigro, of West Kingsdown, Kent, says the first crop produced by their Greengro system will be pak choi, a Chinese green vegetable. This will be sold to wholesaler Rodanto, whose clients include major superstore chains.
The company’s growing system consists of a 42m-long double-skinned polycarbonate tunnel offering up to 400m2 of operating area. Internal conditions are maintained regardless of the weather, with microchips tracking water and nutrient levels in the soil and compost.
Growing materials, all of which are fertiliser free, are sterilised before planting, eliminating the need for pesticides. The system increases energy efficiency by trapping and storing heat during the day for use at night. To shorten growing time to as little as 35 days, carbon dioxide levels are more than doubled.
The process helps the environment by allowing large yields to be grown on a small area of land, regardless of the climate. Crops can therefore be grown in the area where they will be eaten, removing the need for exotic vegetables to be flown in from abroad.
‘The first crop should be around 1,000 tonnes,’ said company director Keith Hamp. ‘We have been very pleased with the results so far and expect the yield to be in line with our expectations. Unigro plans a further 20 tunnels from February.’