The black rot fungus could destroy up to 10% of this year's harvest, a German agricultural institute said yesterday. The Berlin-based Federal Biological Research Centre for Agriculture and Forestry has warned that black rot has primarily affected the northern German vineyard regions of Mosel-Saar-Ruwer, Mittelrhein and Nahe.

The research centre said that the fungus, which blackens and shrivels grapes on the vine, could destroy between 5% and 10% of this year's harvest, as high humidity this month has helped spread the fungus.

The three regions constitute around 10% of Germany's total vineyards.