New defences against a common grape pathogen
There is still only one biological control agent (BCA) that can be used against powdery mildew: a parasitic fungus called Ampelomyces. However, the specific strain of Ampelomyces used at the moment is no longer very effective in controlling the disease. The EU funded a project called 'New biocontrol agents for powdery mildew on grapevine' (BCA_GRAPE) to develop and commercialise new BCAs against powdery mildew. BCA_GRAPE was a consortium of research institutions, farms and small businesses from eight wine-producing states in Europe. Researchers first developed a way to screen different Ampelomyces strains for BCA activity. Using this method, they tested almost 1 000 strains and selected the 10 top performers. These were used to evaluate when in the powdery mildew life cycle they were most effective, and under which environmental conditions. Another branch of the project identified genetic markers to tell the different Ampelomyces strains apart. This will allow scientists to monitor the BCAs in the field after treatment. Finally, a product prototype was developed and tested successfully in the field, showing that these new BCAs can reduce disease outbreaks and intensity in grapevines. The results may also be useful in treating powdery mildew on other fruit such as strawberries.
