Field studies of anthracnose symptoms and pathogen infection in different phases of the persimmon growing season

Abstract

Brazil is currently the world's sixth largest producer of persimmon (Diospyros kaki), with a total yield of 156,935 tonnes in 2018, cultivated in an area of 8148 ha and an average of 22.4 t/ha (Food & Agriculture Organization, 2020). The Brazilian persimmon production is concentrated in the southern and south-eastern regions, with approximately 80% of the cultivated area concentrated in the states of São Paulo (SP), Rio Grande do Sul (RS) and Paraná (PR) (Instituto Brasileiro de Geografia e Estatística, 2020).The cultivars grown in these regions vary depending on the weather and market; for example, in the south-east, cultivars Rama Forte, Fuyu, Guiombo and Taubaté are the most planted, whereas Fuyu and Kyoto are more frequently grown in the south (Aguiar et al., 2014).Persimmons were grown as low-maintenance plants in the south of Brazil, with high productivity and demanding few cultural practices and phytosanitary treatments (Danielli et al., 2002). However, since 2006, mainly in the state of Paraná, growers and extension personnel began to report an increase in the incidence of anthracnose in

Effects of temperature and wetness period on the monocyclic components of persimmon anthracnose

“…Anyway, the development of anthracnose lesions on shoots/twigs over a wide range of temperatures, and the survival of Colletotrichum spp. in one-year-old shoots of persimmon reported by Dolinski et al (2022) highlight the importance of monitoring and constantly removing diseased shoots/twigs from the orchard to reduce the spread of the pathogen to other shoots/twigs and also to leaves, fruit, and flowers.…”

“…Under conducive environmental conditions, conidia is observed in concentric masses of gelatinous pink coloration. Infection of the pathogen can also occur by the flower, and, consequently, the developing fruit may present latent infections that can lead to a severe and premature fruit fall (Carraro et al 2022, Dolinski et al 2022.…”

“…In general, some factors favour the development of the disease, such as warm temperatures and humidity, mainly night temperatures between 20 to 25°C, and also inadequate fertilization and prolonged rainy period in the warmer months, usually at the beginning of fruiting (Dolinski et al 2022). Quantification of the environmental factors that affect the processes of infection and colonization by the pathogen is essential to understand epidemics (Kranz and Hau 1980).…”