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Poster: Epidemiology: Risk Assessment


An impact network analysis for management of Xanthomonas wilt of banana: adoption thresholds for regional success of single diseased stem removal
K. GARRETT (1), C. Ocimati (2), J. Ntamwira (3), G. Blomme (4) (1) University of Florida, U.S.A.; (2) Bioversity, Uganda; (3) Bioversity, DR Congo, DR Congo; (4) Bioversity, Ethiopia

Xanthomonas wilt of banana (BXW) is a major challenge to production for smallholder farmers of Central and Eastern Africa. Lack of resistant varieties and the often high rate of disease spread necessitate timely management. Single diseased stem removal (SDSR; removal at soil level of all visibly infected plants) is a promising approach to management requiring lower labor input compared to the previously advocated whole mat removal. We evaluate SDSR in a regional context using a new framework, Impact Network Analysis (INA). An INA is an evaluation of how technologies can have system-level impact through linked socioeconomic and biophysical networks. Estimates of short-term success rates for on-farm application of SDSR are available for several locations. INA includes projection of long-term regional outcomes based on rates of SDSR adoption. The risk of spread by garden tools is a given, but successful BXW management strategies vary by region. In most highland areas of eastern DR Congo, there is lower insect transmission risk associated with AAA type highland cooking/beer bananas. There, a regional strategy for community-level management does not depend on collective action; individual farmers can effectively manage BXW using SDSR, even if their neighbors do not manage effectively. By contrast, in most lowland areas, collective action is necessary for management, especially in zones planted to ABB type cooking/beer bananas highly susceptible to insect transmission.