Identification, Pathogenicity, and Spore Trapping of Associated with Twig and Shoot Dieback in California.

Corda, 1831 species are well-documented pathogens of citrus that are associated with leaf and fruit anthracnose diseases. However, their role in twig and shoot dieback diseases of citrus has recently become more prominent. Recent surveys of orchards in the Central Valley of California have revealed . and a previously undocumented species, , to be associated with twig and shoot dieback. Pathogenicity tests using clementine (cv. 4B) indicated that both and are capable of producing lesions following inoculation of citrus stems. Pathogenicity tests also revealed to be the most aggressive fungal species producing the longest lesions after 15 months. The majority of spores trapped during this study were trapped during or closely following a precipitation event with the majority of spores being trapped from January through May. These findings confirm as a new pathogen of citrus in California.