TEN YEARS OF FIRE BLIGHT IN AUSTRIA: SURVEY AND CONTROL MEASURES

Erwinia amylovora isolates were differentiated by means of SSRs, some by PFGE pattern and by distinct activities of peroxidases and enhancement of flavanoid and lignin production in infected plant tissue.
Longterm monitoring in defined areas showed that E. amylovora can either remain very homogenous with high SSRs for at least ten years or vary with a shift to SSRs with low numbers, possibly depending on the competitive growth and replacement of certain strains as shown by co-culture.
When traditional orchard cultivars were evaluated good correlations between field observations and artificial infections under greenhouse conditions were observed: 5 out of 15 apple cultivars (‘Falchs Gulderling’, ‘Florianer Rosmarin’, ‘Weberbartl’, ‘Roter Boskoop’, ‘Rheinischer Bohnapfel’) and none of 25 pear cultivars proved to be less susceptible.
In traditional orchards recovery of labelled bees as vectors for biocontrol agents was about 50% depending on the vicinity of other attractive target plants.
The natural occurrence of Pantoea agglomerans in bees’ forage and bee products decreased from 80% in pollen loads to 0% in honey and royal jelly.

X International Workshop on Fire Blight

M. Keck, S. Richter, L. Loncaric, W. Ruppitsch, H. Pechhacker, R. Moosbeckhofer, E. Biosca, K. Geider

Erwinia amylovora, Austria, SSRs, PFGE, histochemistry, local cultivars, bees, Pantoea agglomerans

https://doi.org/10.17660/ActaHortic.2006.704.3