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Cacao (Theobroma cacoa L.) is an important tropical fruit tree used in chocolate production. Among the biotic problems interfering with fruit production, phytopathogenic fungi stand out. During a visit to cocoa production areas in the municipality of Medicilândia, Pará, Brazil (Amazon region), we observed cocoa fruits with dark lesions and greyish‐white cottony mycelia growth. In order to determine the aetiological agent's identity, we extracted DNA and amplified part of the TEF‐1α and RBP2 genes and compared them with sequences in GenBank using the BLASTn tool. Based on molecular results and phylogenetic analysis, the isolates were identified as Calonectria hawksworthii. Inoculations in cacao fruits showed symptoms after 6 days and were similar to those collected in the field, confirming the postulates. This study is the first report of Ca. hawksworthii causing cocoa bean rot worldwide. [ABSTRACT FROM AUTHOR]

The jackfruit tree (Artocarpus heterophyllus) is a tropical species of significant importance, widely distributed in various geographical regions of Brazil, where its fruits, known as jackfruit, are consumed fresh. Between 2019 and 2023, in three distinct geographical regions of Brazil, a 100% incidence of black rot was observed in jackfruit fruits. Additionally, symptoms of dieback were identified in jackfruit trees in these regions. Faced with this issue, the present study aims to identify the etiological agents associated with these two symptoms, employing morphological characterization, nucleotide sequencing, and inoculations in fruits and seedlings. Through sequencing of the ITS, TEF , and TUB2 regions, the isolates were grouped with references of Lasiodiplodia theobromae and L. brasiliense. The inoculated fungi were reisolated, maintaining the same morphological characteristics. This study constitutes the first report of L. theobromae and L. brasiliense as causative agents of fruit rot and dieback in jackfruit in Brazil. • Black rot and dieback disease of jackfruit tree were very popular in three distinct geographical regions of Brazil. • Lasiodiplodia theobromae and L. brasiliense were isolated, identified by morphological and molecular methods, and finished Koch's postulates. • The first report of L. theobromae and L. brasiliense as causative agents of fruit rot and dieback in jackfruit in Brazil. [ABSTRACT FROM AUTHOR]