Fungal Pathogens Associated With Canker Diseases of Almond in California

Almond canker diseases are destructive and can reduce the yield as well lifespan of almond orchards. These may affect trunk branches both young mature trees result in tree death soon after orchard establishment severe cases. Between 2015 2018, 70 orchards were visited throughout Central Valley California upon requests from farm advisors for disease diagnosis. Two major identified, including Botryosphaeriaceae cankers Ceratocystis canker. In addition, five less prevalent Cytospora, Eutypa, Diaporthe, Collophorina, Pallidophorina Seventy-four fungal isolates selected multilocus phylogenetic analyses internal transcribed spacer region ITS1-5.8S-ITS2 part translation elongation factor 1-?, ?-tubulin, glyceraldehyde 3-phosphate dehydrogenase gene sequences; 27 species 12 species, destructans, Cytospora Collophorina hispanica, four Diaporthe two Diatrype Eutypa lata, paarla. The most frequently isolated Neoscytalidium dimidiatum, californica. Pathogenicity experiments on cultivar Nonpareil revealed that Neofusicoccum parvum, arbuti, mediterraneum virulent. predominantly found symptoms trunks trees. was commonly associated with or large scaffold branches. This study provides a thorough examination diversity pathogenicity pathogens branch California.