IMPACT OF FIRE BLIGHT ON ROSACEOUS SPECIES IN CENTRAL ALBERTA

The relatively dry prairie climate of central Alberta does little to constrain destructive outbreaks of fire blight (Erwinia amylovora (Burr.) Winsl. et al.) on a range of roseaceous species.
The most severely affected species are European mountain ash (Sorbus aucuparia L.) and crabapple (Malus coronaria (L.) Mill.). Destructive outbreaks on mountain ash in urban and suburban locations seem to occur in roughly 5 year cycles.
On crabapple, particularly the columnar (Malus baccata ‘Columnaris’) and royalty (Malus x adstingens ‘Royalty’) types, the disease is omnipresent and generally kills trees within 1–2 years of the onset of infection.
Fire blight infections may also be destructive on apple (Malus pumilla Mill.), hawthorn (Crataegus spp.), cotoneaster (Cotoneaster spp.), saskatoon (Amelanchier alnifolia Nutt.) and raspberry (Rubus spp.), but it rarely occurs on pear (Pyrus spp.) and apricot (Prunus mandschurica L.). The disease has never been confirmed on cultivated cherry (Prunus cerasus L.) and plum (Prunus spp.) or their wild relatives in Alberta.

VII International Workshop on Fire Blight

I.R. Evans

https://doi.org/10.17660/ActaHortic.1996.411.7