All rights reserved Forest Pathology volume: 55 startpage: e70019 application/pdf 335572 bytes info:eu-repo/semantics/article Vemić, Aleksandar Jovanović, Sanja Berić, Tanja Lučić, Aleksandar Rakonjac, Ljubinko Mitrović, Suzana Popović, Vladan Abstract: "Due to the intense ash dieback in Europe, which begins with the appearance of leaf infection, this study presents the results of the research on the impact of a selected isolate Pseudomonas koreensis R4.45P on the development of Hymenoscyphus fraxineus in the rachises of Fraxinus excelsior. Preliminary in vitro testing of P. koreensis R4.45P showed a statistically significantly lower growth of H. fraxineus compared to control cultures that were not exposed to this bacterium. The results of the in planta test on F. excelsior seedlings showed a statistically significant decrease in dieback occurrence and the length of necrotic lesions caused by H. fraxineus in rachises treated with P. koreensis R4.45P compared to untreated rachises. Additionally, leaf mortality in F. excelsior seedlings treated with P. koreensis R4.45P was statistically significantly lower. This study is the first to show the possibility of application of antagonistic bacteria P. koreensis R4.45P to effectively slow the initial stage of H. fraxineus development." Keywords: biological control European ash Hymenoscyphus fraxineus infection slowdown Willey https://unilib.phaidrabg.rs/o:8807 doi:10.1111/efp.70019 ISSN: 1437-4781 2025 "The Potential of Pseudomonas koreensis R4.45P to Suppress Hymenoscyphus fraxineus Development in Fraxinus excelsior Leaves" eng