24 November 1995

Potato industry fearful of brown rot devastation

POTATO brown rot could "devastate the entire potato industry", not just the Scottish seed trade, warns an international microbiologist.

Controlling seed imports but allowing unrestricted ware access is "like trying to block the M6 when all the side routes are open", says Tom Stones, technical director of Potex in Hanley, Staffs.

Far from being a hot country disease only, brown rot could survive in the UK, spreading throughout ware production areas in river water and irrigation, says Mr Stone.

He claims to have been "inundated" with calls from concerned growers over the past week, and castigates processors for importing Dutch ware. "It is so shortsighted." Washings from processing plants could be spreading the disease already, he maintains.

If infected, UK crops could be "absolutely devastated". MAFF rules require infected fields to be grassed for three years and withheld from potato production for two more.

So far 35 cases have been confirmed in Holland with 150 more under investigation. EU law says tubers may only be exported from areas which are free, or considered to be free, of infection. Yet ware imports have continued for two months since the Dutch admitted the problem, he says.

"If the boot was on the other foot they would not allow a single tuber in," he says.

Mr Stoner is adamant that anti-rhizomania precautions used by processing plants will not destroy brown rot bacteria. &#42

&#8226 Bacterial disease which can "devastate" potato crops.

&#8226 Only one previous case in UK.

&#8226 35 confirmed and 150 suspected cases in Holland.

&#8226 Ware imports may be bringing disease in already.

&#8226 River water and irrigation can spread the disease.

&#8226 Notifiable in UK.

Unwanted invader? Brown rot (inset – Crown copyright) casts a shadow over the whole UKpotato industry. Sub-surface ring damage is typical.