Antracnose do cajueiro: etiologia, sintomatologia e aspectos epidemiológicos

Abstract

Anthracnose is the most destructive fungal disease on aerial parts of cashew trees. In this review, we addressed the current taxonomy of Colletotrichum species that infect cashew trees in Brazil, as well as their geographic distribution and epidemiological aspects of anthracnose. For a long time, cashew anthracnose was attributed exclusively to C. gloeosporioides, but recent studies revealed at least seven Colletotrichum species as responsible for this disease in cashew trees in Brazil. Among the identified species, C. siamense was the most frequent, occurring in all geographic regions on both cultivated and wild cashew trees. The optimal temperatures for mycelial growth and conidial germination of Colletotrichum spp. ranged between 25–30 C and 27–37 °C, respectively. The wide host range of Colletotrichum species associated to cashew plants constitutes a serious problem for anthracnose management, which is usually focused on chemical control. To a lesser or greater extent, Colletotrichum species were sensitive to azoxystrobin, difenoconazole and thiophanate-methyl. The correct identification of the Colletotrichum species responsible for anthracnose is essential to understand their interactions with the environmental factors that influence the epidemiology of the disease in different hosts, as well as for the improvement of disease control strategies and plant breeding programs aimed to find resistant crop varieties.