Tar spot disease
A leaf disease on maple trees is referred to as tar spot disease , black spot or maple wrinkled scab .
The disease is caused by local fungal infections in the leaves. The fruiting bodies of the parasitic fungus ripen in late summer and are surrounded by intensely pigmented hyphae at this time . As a result, the infected leaf areas turn black and the eponymous clinical picture becomes visible. Two of the Ascomycetes are counting fungi as author of the disease: During Rhytisma punctatum is rather small black spots and exclusively sycamore attacks caused Rhytisma acerinum large black patches of 1-2 cm in diameter. The latter species is far more common and affects both sycamore and norway maples and is occasionally found on other maple species.
The infection occurs in spring and starts from the apothecaries on the fallen leaves of the previous year. Rain and wind loosen the infectious spores and get onto the underside of the maple leaves. This is where the spores germinate. The hyphae penetrate through the underside of the leaf, while the “tar spots” are later always on the upper side of the leaf.
Other types of wrinkled scab parasitize on willows ( willow-wrinkled scab - Rhytisma salicinum ) or rosemary heather (rosemary heather-wrinkled scab - Rhytisma andromedae ).
In the event of severe infestation, it is advisable to remove the fallen leaves in autumn to prevent renewed infestation in the following year.
Web links
- Maple scab. Faculty of Forest Science and Resource Management at the Technical University of Munich ( Memento from December 10, 2012 in the web archive archive.today )
- Tar spot disease on the maple near Arbofux - diagnostic database for woody plants, Weihenstephan-Triesdorf University
Individual evidence
- ↑ Eberhard Brockhaus (ed.): The great Brockhaus . tape 10 .
- ↑ Maple wrinkled scab. In: Spektrum.de Lexicon of Biology. Retrieved August 18, 2020 .