First record of Dothistroma needle blight (Dothistroma septosporum) in the northeast German lowlands.
In April 2015, reddish banding at last year's needles of Pinus jeffreyi Balf. (Jeffrey pine) and Pinus ponderosa Douglas ex C. Lawson (Ponderosa Pine) was found in an Arboretum in the federal state of Brandenburg (Germany). These symptoms were observed in systematic controls at Pinus attenuata Lemmon (Knobcone pine) and Pinus thunbergii Parl. (Japanese black pine) later too. Based on micromorphological investigations and laborative tests, the suspected infection by the quarantine fungus Dothistroma septosporum (Dorogin) M. Morelet (causative agent of Dothistroma needle blight) was confirmed. Only younger trees in an area with persistently high air humidity were diseased. The worldwide occurring pathogen infects mainly pine species (Pinus spp.). It caused serious damage especially in the southern hemisphere until now. Lately however Dothistroma septosporum was remarkably often detected in several European countries. The increased presence of the fungus north of the Equator is supposed to originate in the recognizable climate change of the last few decades. The pathogen is capable of damaging the native to Europe Black pine (Pinus nigra J.F. Arnold) considerably. Therefore forestry risks result. In addition, it is unclear, what intensity an infestation of pure stands of Scots pine (Pinus sylvestris L.) would reach.