First detection of tomato powdery mildew caused by Oidium neolycopersici in South Africa

• We studied material of tomato powdery mildew found on Solanum lycopersicum in South Africa.
• Comparative morphological characterization showed same morphological features as for Oidium neolycopersici.
• Molecular studies confirmed identity of this species, four identical rDNA ITS sequences were determined.
• We provide the first scientific evidence that the powdery mildew Oidium neolycopersici occurs in South Africa.
• Worldwide distribution and epidemiological consequences of this record are discussed.

Oidium neolycopersici has a world-wide distribution causing severe epidemics mainly on greenhouse tomatoes. Currently, only Leveillula taurica has been reported on tomato from South Africa. However, another powdery mildew species on tomato was found recently. Based on morphological comparison and molecular analysis, its identity was confirmed as O. neolycopersici. The possible means of introduction and other aspects of this finding are discussed.