FIRE BLIGHT RESISTANCE IN EXTENSIVE POME FRUIT PRODUCTION IN GERMANY

Fire blight outbreaks and the occurrence of Erwinia amylovora were monitored during the years 2002 and 2003 on apple and pear cultivars in extensive fruit production in the regions of Lake Constance and Rheinhessen.
Correspondingly, resistance testing under the conditions of artificial infection was done.
In both years, mainly pear trees were affected by the disease under natural conditions.
The cultivars ‘Oberösterreicher’ and ‘Nordhäuser Winterforelle’ were observed as highly susceptible.
The cultivar ‘Oberösterreicher’ was affected most seriously by shoot infection in 2003. In apple orchards, in the year 2002 infections were rare, but during 2003 symptoms could be observed on the cultivars ‘Brettacher’, ‘Pilot’, ‘Jakob Fischer’ and several unidentified varieties.
Resistance testing under the conditions of artificial infection showed the pear cultivars ‘Nordhäuser Winterforelle’ and ‘Oberösterreicher’, and the apple cultivars ‘Pilot’ and ‘Rote Schafsnase’ to be highly susceptible.
Summarizing the investigations under both conditions, artificial and natural infection, as yet only the apple cultivars ‘Bohnapfel’ and ‘Rewena’ have been identified with low susceptibility.

X International Workshop on Fire Blight

P. Laux, W. Zeller

Erwinia amylovora, apple, pear, susceptibility, monitoring

https://doi.org/10.17660/ActaHortic.2006.704.84