Assessment of the current status of and characterization mango anthracnose (Colletotrichum gloeosporioides) isolates in Wolaita zone, south Ethiopia

Abstract

Mango anthracnose (Colletotrichum gloeosporioides) poses a significant threat to small-scale mango producers in the Wolaita zone of southern Ethiopia. This study investigated the disease's incidence and severity, along with characterizing the pathogen and its impact on mango production in the area. Disease incidence was determined by examining eight randomly selected mango plants per farm field, while severity was assessed by measuring the percentage of leaf/fruit area infected on eight randomly selected plants. Laboratory analysis focused on characterizing C. gloeosporioides isolates collected from infected plant material. Conidial morphology was examined by measuring the length and width of 20 conidia per isolate. Cultural characteristics, including colony growth, color, form, and diameter, were also documented for each isolate grown on potato dextrose agar. Results revealed a high incidence of mango anthracnose in the surveyed orchards, ranging from 60.5% to 84.0% on leaves and 70.8% to 79.0% on fruits. Disease severity also varied significantly between locations, with leaf severity ranging from 39.75% to 76.75% and fruit severity ranging from 40.25% to 57.15%. Morphological analysis of C. gloeosporioides isolates revealed an average conidial length of 10.65 μm and width of 4.46 μm. Colony morphology on potato dextrose agar exhibited variability, with an average diameter of 34.47 mm and the lowest mycelial growth of 18.18 mm. The study highlights the significant threat of mango anthracnose to mango production in the Wolaita zone. The observed variability in disease severity and pathogen characteristics underscores the need for location-specific disease management strategies. Future research should focus on developing effective and affordable control measures for mango anthracnose in the Wolaita zone, considering the observed variability in disease severity and pathogen characteristics.