Prospecting brown rust of sugarcane in São Paulo-Brazil under climate change scenarios.

Climate change can cause significant shifts in the occurrence and severity of agricultural diseases, altering the distribution of phytosanitary problems with severe economic, social, and environmental consequences. Despite their importance, these new geographic and temporal distributions of plant diseases still demand scrutiny. In the present study, we prospect the geographic distribution of sugarcane brown rust (Puccinia melanocephala) considering average temperature and relative humidity in the main producing region of the state of São Paulo. The geographic database was structured using GIS with projections of future climate change provided by IPCC. Mathematical logic equations were defined and applied to data of average temperature and relative humidity, resulting in monthly maps of climate favorability for the occurrence of the disease. Prospective maps for three future periods (2011-2040, 2041-2070, and 2071-2100) and two greenhouse gas emission scenarios were compared to the reference period (1961-1990). The analysis considered months from December to May. Our study shows a tendency of decrease in the favorability for the disease in a longer term (2071-2100), more noticeable in the scenario A2 than in B1. These results suggest; however, that this disease demands attention in the management of the producing region for future climate scenarios