ESTABLISHMENT AND SURVIVAL ON APPLE AND PEAR LEAVES OF FOUR BIOLOGICAL CONTROL AGENTS INCLUDING PANTOEA AGGLOMERANS P10C AND PSEUDOMONAS FLUORESCENS A506

The ability of four different bacterial strains to establish and colonise apple and pear leaves was determined.
Those four strains were selected for their ability to colonise apple and pear flowers and to reduce incidence of fire blight when sprayed on apple or pear flowers before inoculation with Erwinia amylovora. Three of these strains are Pantoea agglomerans, including the strain P10c which is sold commercially in New Zealand, the fourth strain is the strain of Pseudomonas fluorescens A506 which is sold commercially in the USA. These strains were individually sprayed on apple or pear leaves in the laboratory or in the field.
The percentage of leaf surface colonised by the different bacteria was assessed by imprinting leaves onto fresh agar plates.
Correlations between the percentage of leaf area colonised by a bacterial strain and the concentration of bacteria used to spray the leaves and between the percentage of leaf area colonised and the population recovered from the leaves were first established.
The strain of P. agglomerans P10c was able to survive on apple leaves for a longer period of time than E. amylovora. The strain of P. fluorescens A506 did not survive for more than two days in the field while the strains of P. agglomerans survived for several days but the percentage of leaf area colonised decreased rapidly after 48 hours.
These strains might not have the characteristics necessary to control fire blight infection on shoots during the summer period.

X International Workshop on Fire Blight

J.L. Vanneste, D.A. Cornish, J. Yu, F. Spinelli

Erwinia amylovora, fire blight, shoot blight

https://doi.org/10.17660/ActaHortic.2006.704.44