A system to map the risk of infection by <i>Puccinia kuehnii</i> in Brazil

Abstract

Orange rust caused by the fungus Puccinia kuehnii greatly affects sugarcane and causes millions of tons of losses in production. This condition was first reported in Brazil at the end of 2009. The disease is currently present in most of the countries that produce this crop. The aim of this research was to develop risk maps of P. kuehnii infection using temperature and relative humidity data, provided by 389 automatic weather stations throughout the country. A spatial distribution analysis was carried out to assess the number of daily hours of favorable conditions for spore germination in each region. In the central-south region, where the main sugarcane producing states are concentrated, two distinct periods were observed during the three years studied. Higher favorability occurred from October to April, and lower favorability occurred from May to September. The opposite relation was observed on the coast of the north-eastern region, where conditions were more favorable to the disease from May to September. The validation data were confirmed by the results of Pearson's correlation between sugarcane orange rust infection under field conditions and the proposed maps. In conclusion, risk maps obtained using data from automatic weather stations could contribute to the monitoring of the risk of infection by sugarcane orange rust.

Climate risk scenarios of orange rust for the sugarcane-producing regions of Argentina and Brazil

“…Sangel et al (2019 also found that high summer temperatures negatively affected the development of orange rust. In this context, we found a reduction in favorability for the occurrence of this disease in the main sugarcane-producing regions of Argentina and Brazil, from December to February and from December to March, respectively, due to the increase in mean air temperature predicted for the periods 2011-2040, 2041-2070 and 2071-2100. Climatic risk maps of P. kuehnii infection using monthly temperature and relative humidity data from 2008 to 2010 also showed variability of favorable conditions to orange rust for Brazil (Sumida et al, 2019). In this study, there was greater favorability for the occurrence of the disease from December to May; since the entire country of Brazil was considered, without distinction of the producing areas.…”

“…All these studies have in common is the use of an important tool for the identification of areas with favorable climatic conditions for the development of the pathogen. Therefore, the monitoring of these areas of risk for the occurrence of diseases, through maps of geographic and temporal distribution, can be a preventive measure, seeking actions to prevent the entry of the pathogen, as well as the indication of tolerant cultivars in areas with favorable environmental conditions (Sentelhas et al, 2016;Sumida et al, 2019). These measures should be adopted by the main sugarcane-producing areas of Argentina and Brazil.…”

“…Epidemiological data of the disease associated with the use of geographic information system allow the analysis of the spatial distribution of plant diseases (Sumida et al, 2019;Sentelhas et al, 2016).…”