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Poster: Epidemiology: Climate Change


Distribution models of common bean dry root rot in Brazil: current and predicted disease distribution in climate change scenarios
R. Macedo (1), L. Abud (1), F. Yoshida (1), L. Sales (1), E. Barbosa (2), M. Lobo (2), R. Macedo (1) (1) Universidade Federal de Goiás, Brazil; (2) Brazilian Corporation for Agricultural Research (Embrapa), Brazil

Dry root rot is an ubiquitous problem on common beans in Brazil, with yearly yield losses attributed to the Fusarium solani species complex. Species distribution models (SDMs) based on 21 field disease records were developed to assess dry root rot current geographical distribution, and estimate disese range expected in IPCC scenarios A1B and A2 by the year 2030. Projections were adjusted by an ensemble of three modelling methods: Generalized Adittive Models, Surface Range Envolop and Artificial Neural Networks, built with “biomod” and “raster” packages from R statistical software. Also, we verified if three inoculum threshholds (1200, 3700 and 4500 propagules of F. solani per soil, in 2623 records) could work as disease spatial proxies, supported by Sperman’s correlations between inoculum thresholds and disease records. The best disease × soil inoculum density correlation was found with 3700 progules per soil gram (r=0.85, P<0.001). The current projection shows high climatic suitability for common bean dry root rot in the Brazilian central region. According to IPCC scenarios, the geographical area affected by the disease will be reduced by almost 23%, but highly favorable areas will move towards Brazil South Region, which represents 40% of the country’s common bean yields. Implications and consequences of these results will be discussed to support future plans on root rot management.