Fears of a UK mushroom shortage intensified this week as producers counted the cost of a mushroom-blight disease at the UK's largest compost supplier.
Tunnel Tech North was hit by an outbreak of trichoderma aggresivum at its South Yorkshire site three weeks ago. The outbreak has now been largely eradicated, according to the company, but some growers have had to throw compost away and seek supplies from abroad.
Trichoderma, which manifests itself in the form of a green mould, is particularly harmful to mushrooms as it competes with the infantile fungi below the surface of the soil. Once the mould reaches the surface, its spores can result in brown spotting on the surface of mature mushroom caps, which often do not appear until after the mushrooms have been picked.
The traditional difficulties of mushroom production during the hot summer months coupled with the trichoderma problem could lead to a shortage of UK product, warned John Smith, MD of mushroom grower Greyfriars. "We could be entering a period of difficulty for those supermarkets that have an unusual dependence upon UK supplies," he added.
The disease was affecting mushroom production across Europe, added Tim Harker, director and general manager of Tunnel Tech. The Horticultural Development Company was researching ways to combat the problem, he added.
The outbreak has hit UK suppliers just as imports have come under pressure as a result of the weakening pound. Many Polish, Dutch and Belgian producers have been considering ending supply to the UK following sterling's drop in value, while Irish growers warned the low mushroom retail price was making production unsustainable.
UK growers have been unable to expand production to reduce the reliance on imports due to a general lack of compost.