Biological, chemical, cultural control methods and determination resistant cultivars to fire blight in pear orchards in the eastern Mediterrenean region of Turkey

Total of 139 bacterial isolates were collected from pear orchards in Eastern Mediterranean Region of Turkey, and in vitro tests (on appropriate medium and immature pear fruit tests) showed that 49 isolates were effective against fire blight disease. Two antagonists isolate reduced development of disease symptom on pear flowers in a rate of about 50% in vivo conditions. Prevention of the disease development by the same antagonists was as effective as Erwinia herbicola and streptomycin sulfate on pear. In this study, effects of combination of copper compounds and pruning on the control of fire blight were also investigated. The first fungicide application was started at white rosette stage in pear orchards planted with Pyrus communis cv. Santa Maria, susceptible cultivar to fire blight. The branches were pruned about 15-20 cm below the infected area, at the same time as fungicide application. The effectiveness of pruning alone was found 62.47% while the effectiveness of copper compounds was alone 30.60-69.74%. The best result was obtained from the combination of copper oxychloride+pruning with 70.16% effectiveness. In the resistance screening studies with 13 different pear varieties against Erwinia amylovora showed that Lemon, Kieffer and Migirik were weakly susceptible; Ankara, Mustafa bey, Cermai and Had Hamza were middle susceptible; Akca, Williams, Santa Maria, Laleliye, Deveci, and Moonglow were highly susceptible.