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Studies on the pathogenicity of Neoerysiphe galeopsidis on Catalpa, Acanthus and Lamium
powdery mildew, pathogenicity, Neoerysiphe, Catalpa, Acanthus, Lamium, Althaea
After the first finding of catalpa powdery mildew caused by Erysiphe elevata at RHS Garden Wisley in 2002, work done over the next three seasons showed that the disease in England can be caused by at least four species. Neoerysiphe galeopsidis was found in June/July on Catalpa, but became overrun by Erysiphe elevata later in the season.
Unlike the other powdery mildew species, N. galeopsidis is found on a wide range of wild and cultivated plants. It was responsible for serious damage to Acanthus at RHS Garden Wisley in 2005.
Work is needed to determine whether N. galeopsidis from Acanthus can infect Catalpa and vice versa, and whether N. galeopsidis from wild plants, e.g. Lamium, can infect either of these hosts.
It seems likely that N. galeopsidis has recently broadened its host range in certain parts of the world. To confirm, the following experiments are planned:
The project will provide information about the host range of Neoerysiphe galeopsidis, which can be applied for the management of the disease.
More on powdery mildew
Cook R T A, Henricot B, Henrici A and Beales P (2006) Morphological and phylogenetic comparisons amongst powdery mildews on Catalpa in UK. Mycological Research 110, 672-685.
Cook R TA, Henricot B and Beales P (2006). First report of Neoerysiphe galeopsidis on Acanthus spinosis in the UK. Plant Pathology 55, 575
Read the report
Cook R T A, Henricot B and Kiss L (2004). First record of Erysiphe elevata on Catalpa bignonioides in the UK. Plant Pathology 53, 807.
Read the report
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