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Glomerella leaf spot (GLS) is an apple disease that concerns growers due to the increases in severity over the years and the difficulties in control. Species within the Colletotrichum acutatum and C. gloeosporioides species complexes cause GLS, but the proportion of species within each complex in Brazilian apple orchards is not known. The objectives of this study were to identify isolates of Colletotrichum causing GLS on apple orchards in the main Brazilian producing regions to the species level. Two hundred and seven isolates were obtained in orchards in São Paulo (SP), Parana (PR), Santa Catarina (SC), and Rio Grande do Sul (RS) states. Genomic DNA was extracted, and the ITS, GAPDH, CHS-1, and TUB2 genes were amplified and sequenced. The phylogenetic trees were generated using a concatenated alignment. One hundred and fourteen isolates were identified as belonging to the C. acutatum species complex (Cac) and 93 to the C. gloeosporioides species complex (Cgc). Five phylogenetic species were identified: C. melonis (1.9%), C. nymphaeae (47.4%), C. paranaense (2.4%), C. limetticola (3.4%), and C. fructicola (44.9%). In SC, Cgc predominates, but in the states of SP, PR, and RS, Cac was predominant. This is the first report of C. limetticola from apple.

European Canker and Neonectria fruit rot (NFR), caused by Neonectria ditissima, has become a major problem for the production of apples (Malus domestica) in Brazil. This study characterized environmental factors affecting in vitro growth and germination of Neonectria ditissima as well as infection, colonization and reproduction, ex vivo, on 'Gala' and 'Eva' fruit. Temperatures between 17 to 20 °C were optimum for mycelial growth, and minimal growth occurred at 35 °C. Micro/ macroconidia sporulation ratio was lower at 10 °C for most of the isolates tested, and no macroconidia were produced at 30 °C. More than 70% of conidia germinated after 12 h of exposure to constant humidity incubation and a temperature of 25 °C. Germination rate as high as 90% occurred after 48 h regardless of the temperature. Incubation of 2 h with high humidity is not sufficient for germination of 10% of conidia at any temperature between 10 to 30 °C. The cultivars Eva and Gala did not differ in relation to incubation period. A minimum of 25 days was necessary for sporulation on fruit incubated at 16.8-21.7 °C. Unwounded fruit did not present symptoms even 40 days after inoculation on intact epidermis, demonstrating the need of wounds for NFR development.

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