Association of First Report of Botryosphaeria Spp. With Almond Dieback and Gummosis in Türki̇ye

Abstract Türkiye is among the top-producing almond countries in the world. Almond is a precious nut in modern diets due to its bioactive compounds associated with health and disease treatment. However, the plant's yield is affected by factors, including pathogens. This study aimed to diagnose and identify biotic factors associated with decline, dieback, and gummosis in almond trees in Yozgat province with a temperate climate. Seven almond 10-year orchards were investigated and trees with symptoms were sampled. Isolated species were cultured in PDA medium to identify the morphological and cultural characterization. The results obtained with cultural and morphological characteristics along with Phylogenetic analysis of ITS, β-tubulin, and EF-1α sequence data, confirmed the presence of Diplodia seriata , Lasiodiplodia theobromae , Neofusicoccum parvum, Botryosphaeria dothidea. Among these species, Botryosphaeria dothidea was first reported from almond trees in Türkiye. Pathogenicity testing showed that although all species were virulent , L. theobromae and N. parvum isolates caused more gumming in the inoculation areas than D. seriata and B . dothidea isolates. These results confirm that multiple Botryosphaeriaceae species are associated with branch decline and dieback on almond in Türkiye, which agrees with similar studies on woody crops. Accurate diagnosis of fungal pathogens in almonds is vital for developing disease management strategies and may help improve horticultural practices in maintaining urban stands.