REDUCTION OF FIRE BLIGHT INCIDENCE ON APPLE FLOWERS AND COLONISATION OF PEAR SHOOTS IN EXPERIMENTAL ORCHARDS USING PSEUDOMONAS SPP. IPV-BO G19 AND IPV-BO 3371

The two strains of fluorescent Pseudomonas sp.
IPV-BO G19 and IPV-BO 3371 were previously found to be able to reduce fire blight incidence on apple and pear flowers and on pear shoots if sprayed before inoculation with Erwinia amylovora. The aim of these experiments was to confirm the ability of these two strains to establish and to colonise apple flowers and pear shoots, and to confirm their ability to reduce incidence of fire blight on apple flowers in experimental orchards.
Strain IPV-BO G19 was able to colonise apple flowers in the laboratory, reaching population of approx. 10⁷ cfu/flower in four days.
Similar results (10⁵ cfu/flower) were obtained when this strain was sprayed on apple flowers ‘Pink Kiss’ in an experimental orchard in Hamilton, New Zealand.
When sprayed 24 hours before inoculation with E. amylovora on flowers of apple trees ‘Braeburn’ in another experimental orchard, IPV-BO G19 and IPV-BO 3371 reduced fire blight incidence by 78% and 58%, respectively, while in the same experiment streptomycin reduced disease incidence by 92%. The ability of these two strains to colonise pear shoots was investigated by leaf imprints on KB-plates.

X International Workshop on Fire Blight

E. Biondi, C. Bazzi, J.L. Vanneste

Erwinia amylovora, antagonists, rifampicin resistant mutants, inhibitory activity, biological control

https://doi.org/10.17660/ActaHortic.2006.704.47