Olive anthracnose is caused by different species of fungi, with distinct geographic distribution, virulence and preference for the cultivar

Abstract

Olive anthracnose is the main phytopathological limiting factor affecting olive production in Portugal. It causes the fall or mummification of olive fruits, with the consequent loss of production and/or depreciation of olive oil quality. In Portugal, disease incidence ranged between 30 and 50% while disease severity was on average 14%. Olive anthracnose is caused by several species belonging to the genus Colletotrichum, being C. nymphaeae and C. acutatum sensu stricto the most virulent, while C. godetiae and C. fioriniae presented intermediate virulence and C. gloeosporioides (among others, less frequent) shower lesser virulence. In the centre and south of Portugal prevails C. nymphaeae, while in Trás-os-Montes C. godetiae is more frequent. However, variations in virulence depend on the interaction with the cultivar. For example, in 'Cobrançosa', C. godetiae presents greater virulence than C. acutatum s.s., contrary to the general average. Variations in the virulence of these pathogens, their interaction with olive cultivars, their geographic distribution and recent population dynamics should be taken into account and understood for the implementation of measures to protect olive groves.