Super-blight not a worry here, says ADAS pathologist
SPECULATION that aggressive new blight strains and overwintering resting spores played a significant part in last years epidemic is being played down.
Dutch plant pathologist Huub Schepers says UK growers face the same threat of aggressive, fungicide resistant blight to that faced by growers on the Continent.
Crosses between the A2 and more widespread A1 races of blight can lead to more aggressive blight and earlier infection by overwintering oospores, he warns.
But ADAS plant pathologist Nick Bradshaw is unconvinced. "At present, the situation here is not the same as on the Continent."
MAFF-funded blight research shows the A2 strain is rare in the UK, accounting for only about 3% of field isolates, adds Jenny Day of the University of Wales, Bangor. "If transmission via oospores was important, you would expect to have equal amounts of A1 and A2 strains."
lUS growers have suffered severe losses from the aggressive US8 strain, thought to have arrived from Mexico, which can require 25% more fungicide to prevent losses. *
Suggestions from Dutch expert Huub Schepers that super-blight was to blame for last years poor blight control are dismissed by UK specialists.