Diagnosis and integrated control of fire blight causal agent (Erwinia amylovora) on quince

The aim of this work was classical and molecular diagnosis, and evaluation of integrated control possibilities of Erwinia amylovora (Ea) strains obtained showing from fireblight symptoms on pome fruits. In this thesis, Pantoea agglomerans (Pa - Eh24, E325), P. vagans (Pv - C9/1) and Pseudomonas fluorescens (Pf - A506) and the chemicals such as Oxolinic acid (OA), Prohexadione Calcium (ProCa) were extensively studied for control of Ea on immature pear fruits (IPFA) and detached blossoms of quince. OA effectively inhibited Ea development on IPFA, it was followed by Pa - E325. Tested bacterial antagonists significantly reduced the percentage of blighted blossoms on detached quince blossom assay by 33 % to 55 % compared to the untreated control. However, OA and ProCa treatments couldn't inhibit the blossom blight of Ea on detached quince blossom assay. Then, the selected bacterial antagonists (PfA506, PaE325, and PvC9/1), ProCa and streptomycin were applied onto one year old quince transplants (cv. Ege1) as spray treatment. Ea inoculation was performed by injecting the pathogenic bacterial suspension into the apical bud of quince transplants 24h after treatments. Pv - C9/1 and Pf - A506 inhibited the development of shoot blight on quince transplants at the rate of 81 % and 77 % compared to pathogen alone treatment, respectively, and found more promising than streptomycin treatment (100 µg/ml). ProCa was uneffective to inhibit the shoot blight symptom of Ea on quince transplants.