Distribution and Identification of Anthracnose of Papaya Caused by Colletotrichum Gloeosporioides in the Central Rift Valley of Ethiopia

Abstract

Papaya (Carica papaya L.) is one of the most important fruit crops in Ethiopia. Despite its importance, papaya production is hampered by different biotic and abiotic factors. Among biotic factors, anthracnose is an important disease, causing serious damage to papaya, especially in the postharvest stage. The surveys were conducted in eight kebeles (smallest administrative unit) of three districts (Adama, Adamitulu Jidokombolcha, and Dugda) in the East Shewa Zone of the Oromia regional state, Ethiopia from August to September 2016 and August to September 2021, to assess the prevalence, incidence, and severity of papaya anthracnose disease. Disease incidence and severity on leaves and fruits were determined using random sampling techniques. Cultural and morphological characterization of the causal agent of papaya anthracnose was also done. The survey results showed that all the eight kebeles assessed during 2016 and 2021 were affected by papaya anthracnose disease. The overall mean incidences of the disease were 63.9% on the leaves and 40.3% on the fruits while average disease severities were 24.8% and 22.8%, respectively. Disease incidences in different kebeles ranged from 60 to 66.7% on leaves and from 30 to 48.9% on fruits. Disease severity also varied from 21.1 to 29.8% on leaves and from 20 to 26.7% on fruits. Disease incidences and severities were generally higher in Wolda Kelina kebele. In 2021, the assessment result indicated that in Dugda and Adamitulu Jidokombolcha districts anthracnose was a major papaya production constraint. Based on field symptomatic assessment as well as cultural and morphological characterization, Colletotrichum gloeosporioides was identified as the causal agent of the disease threatening papaya production in the surveyed areas. These findings provide information on the magnitude of the damage due to papaya anthracnose disease and will be useful to devise disease management strategies. It is necessary to investigate the reactions of the available papaya cultivars against the pathogen and select disease tolerant papaya materials.