Prevalence and Incidence of Cassava (Manihot esculenta) Brown Leaf Spot Disease Caused by Cercospora heningsii in Macuata Province, Vanua Levu, Fiji

Abstract

Cassava (Manihot esculenta Crantz) is a crop of many values in the tropical and subtropical regions of the globe. In Fiji, cassava is cultivated on vast acres of land but, the yield obtained is relatively lower because of many constraints, including the prevalence of diseases caused by the different pathogens. Among various pathogens responsible for a lower yield, the cassava brown leaf spot disease caused by Cercospora heningsii is responsible for causing enormous annual losses of cassava in tropical and subtropical regions. Because there is very little information regarding the association of the brown leaf spot disease and cassava in the country, the present study using survey as research instrument endeavors to determine the disease incidence and prevalence of brown leaf spot disease in the cassava fields of three villages (Mani Road, Boca, and Anuve) in the Bulileka area of the Macauta province in Vanua Levu, Fiji. The study found that brown leaf spot disease prevailed (100%) in all three villages. The percentage of disease incidence ranged from 36.4% to 42.9%. The maximum incidence (42.9%) of cassava brown leaf spot disease was found in Anuve village, followed by Mani Road village (38.2%), with the lowest disease incidence recorded for Boca village (36.4%).

First Time Morphological and Molecular Isolation of Epicoccum sorghinum Pathogenicity in the Cassava Brown Leaf Spot Disease in Kenya

“…Furthermore, occurrence of the brown leaf spot disease in Kasukari variety in Kitui is a phenomenon that can result to high yield losses in cassava based on the fact that at least each root had a trace of root necrosis and none was identi ed to be healthy. For example, BLS are responsible for enormous annual losses of cassava in tropics and subtropics [9]. Additionally, the infection caused by BLS may lead to mycotoxicity and affected cassava thus upon consumption can be poisonous.…”

“…The growth and yield of cassava are impacted by biotic constraints among which pathogenic diseases are of signi cance [9]. Furthermore, early identi cation of the disease in the eld is a critical initial step in managing the detection and distribution of cassava leaf diseases [10].…”

Characterization of the Cassava Mycobiome in Symptomatic Leaf Tissues Displaying Cassava Superelongation Disease

“…In susceptible cassava varieties, cassava anthracnose disease (CAD) caused by Colletotrichum gloeosporioides presents as stem and petiole cankers, followed by extreme necrotic lesions and defoliation, resulting in crop losses of more than 30% [7,8]. Similarly, C. henningsii, synonym Mycosphaerella henningsii, which causes cassava brown leaf spot disease, is reported to have caused a yield decline of 17-30% in Africa, South America, and Asia [9][10][11]. Another caused a yield decline of 17-30% in Africa, South America, and Asia [9][10][11].…”

“…Similarly, C. henningsii, synonym Mycosphaerella henningsii, which causes cassava brown leaf spot disease, is reported to have caused a yield decline of 17-30% in Africa, South America, and Asia [9][10][11]. Another caused a yield decline of 17-30% in Africa, South America, and Asia [9][10][11]. Another cassava fungal disease of economic interest in Latin America and the Caribbean is the SED, caused by the fungal pathogen E. brasiliensis [5,12].…”