Observation en Hollande de la forme parfaite du champignonGloeosporium perennans Zeller et Childs

Summary

In October 1956 apothecia, belonging toPezicula malicorticis (Jackson)Nannfeldt (=Neofabraea malicorticis (Cordley) Jackson), the perfect stage of the parasite known in plant pathology literature asGloeosporium perennans, have been found on naturally infected appletrees in Druten and near Deest (Land van Maas en Waal) and on appletrees at Wageningen, which had been inoculated with mycelium ofG. perennans in October 1955. The apothecia occurred as well on the surface of the bark as in old conidial fructifications; they were sessile, clearly convex, bright-yellow under moist conditions and brownish when old or dry. The diameter of the apothecia was 0,4–1,6 mm. As many as 100 apothecia were found on a square cm. It is put forward that the formation of the apothecia has been favoured by the very wet weather of the preceding summer.