Analysis of the spatial distribution and association of banana wilt (Fusarium oxysporum f. sp. cubense) with biophysical factors in Gamo zone, southern Ethiopia

Abstract

Banana wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most important diseases of banana (Musa L.) worldwide including Ethiopia. Foc is responsible for sever yield losses of up to 90% in commercial and local banana cultivars planted in southern Ethiopia. However, there is limited research information about its epidemiology, distribution, and relative importance of the disease in the country particularly in Gamo zone, southern Ethiopia, where banana is dominantly grown. Hence, this study was conducted to investigate and analyze the distribution, importance, and intensity of the disease and its association with biophysical factors. Fields surveys were conducted in three major banana-growing districts of Gamo zone in Arba Minch Zuria, Mirab Abaya, and Daramalo during the 2019/2020 cropping season in which a total of 90 fields were surveyed. The association of the disease incidence and severity with independent variables was analyzed using a logistic regression model in SAS under the GENMOD procedures. The results of the survey study indicated that Fusarium wilt was widely distributed all the three districts, regardless of agro-ecological factors. The highest mean incidence (47.37%) and severity (46.31%) values were recorded at Daramalo, while the lowest incidence (20.75%) and severity (28.63%) values were recorded from Arba Minch Zuria district. Variables such as banana cultivars, age of plantations, weeding practices, and disease management methods were significantly associated with the incidence and severity of the disease. The use of improved cultivars reduced disease incidence by 43.60% and the severity by 30.10%, compared to that of local ones. Regression analysis of the biophysical factors with Fusarium wilt severity implied the necessity of effective and feasible integrated management options to be developed against the disease and as well as the importance of awareness raising with all stakeholders regarding its distribution, importance, and possible management options such as the usage of Foc-resistant varieties in the study area.