Industry benefits from new blight research
Research carried out as part of the British Potato Council Fight Against Blight (FAB) campaign has helped develop industry understanding of blight populations in Britain. Although the prevalence of the newer A2 blight genotypes(1) has risen, the latest findings suggest the number of different genotypes is stable, safeguarding current strategies for tackling the disease.
"In 2006 we studied samples sent in by blight scouts and from other sites to develop our understanding of how blight populations are changing," reported BPC R&D director Mike Storey. "We found the A2 blight strain at 66 per cent of the sites we tested. Mixed mating types were found at 22 per cent of sites."
Eight samples were analysed per outbreak of blight, compared with one in 2005, when the A2 blight strain was found at 38 per cent of sites. "Last year the blight scouts did an excellent job of identifying outbreaks and sending samples in for analysis. We now have a much a clearer idea how populations are developing," Dr Storey told scientists and other industry experts, who gathered at the BPC's UK Blight Forum in Peterborough this week.
"Despite a rise in the A2 population, genetic analyses so far have revealed that the number of different genotypes within the population has not risen significantly(2). This indicates that strains are not successfully mating in Britain and producing oospores which could otherwise lead to difficulties controlling the disease."
So far no oospores have been found in GB crops, reported Dr Storey. Unlike asexual blight inoculum, that survives between seasons on green material such as volunteers or on tubers, oospores can survive in soil for several years and their spread is harder to check.
"We need to be aware that oospores may be produced, so with industry support we will be maintaining current levels of research and blight monitoring through the network of scouts," said Dr Storey.
"Growers should ensure they maintain fungicide programmes that their buyers are happy with. Our current fungicides, varieties and warning systems have helped us maintain a robust defence against these blight populations(3). So there's every reason to trust current best practice to keep blight at bay. But above all, we all need to stay alert for signs of blight and control sources of infection such as outgrade piles and volunteers."
Dr Storey urged growers and advisers to make good use of the BPC's FAB service and BlightWatch(4) to ensure they are notified of local outbreaks and conducive conditions for blight in good time. "Sign up for the SMS and e-mail alerts – it is a system that has been proven to nip potential blight epidemics in the bud. But it only works if growers stay alert and react."
The FAB campaign has been enormously successful at raising awareness of blight and highlighting best practice for its control, said Dr Storey. "Growers owe the network of blight scouts and super scouts a huge debt of gratitude. These volunteers are ensuring we have up-to-date and reliable information on how Britain's blight populations are developing."
