Alerts issued by Epagri help control a disease that could decimate soybean crops

Soybean producers in the main producing regions of Santa Catarina have received messages on their cell phones warning of the favorable occurrence of Asian rust. The service, provided free of charge by Epagri, helps the farmer make decisions regarding the application of fungicide to combat the pathogen that causes the disease. The objective is to reduce costs and increase the sustainability of grain crops in the State.

Eduardo Briese Neujahr, extensionist at Epagri's Regional Management in Campos Novos, explains that the uredospore of Phakopsora pachyrhizi is the cause of Asian soybean rust, a disease capable of decimating the entire crop production. To avoid the onset of the disease, the farmer needs to combat the pathogen in a preventive manner, but as long as there are conditions that favor the occurrence of the disease. With the information provided by Epagri and support from the technician who monitors your crop, the rural producer can make this application more rationally, only when it is really necessary. 

Monitoring takes place in 27 municipalities in the regions of Campos Novos, Xanxerê, Canoinhas and Rio do Sul. Every week, Epagri extensionists visit soybean fields that have uredospore collectors. They analyze whether or not the plants show symptoms of Asian rust and collect the blade installed in the spore collector. This slide is sent to a laboratory, which evaluates the presence or absence of the pathogen. This assessment is carried out in laboratories at Epagri or the University of Western SC (Unoesc). 

The information is centralized at the Epagri Experimental Station in Ituporanga. There, the phytopathologist and researcher Edivânio Rodrigues de Araújo, in addition to evaluating the slides collected in the Alto Vale region, creates a map containing information about the presence or absence of the uredospore, the presence or absence of symptoms in the plants and the climatic favorability for the development of the illness in the last seven days. This last information is taken from Agroconnect, a phytosanitary alert platform created and maintained by Epagri/Ciram. 

Combination of factors

Eduardo explains that a combination of three factors is necessary for the occurrence of Asian soybean rust. In addition to the plant and the presence of the uredospore, it is necessary to have a favorable environmental condition, which is characterized by the simultaneous occurrence of an air temperature between 18 and 25ºC and at least six consecutive hours of leaf wetness. 

Monitoring has been carried out by Epagri since 2020 and last October the distribution of weekly bulletins began, which are sent via WhatsApp to technicians, who pass them on to the farmers assisted. At the beginning of February, the newsletters will be sent out, as the plant will already be at a stage where it is no longer possible to carry out preventive work against the disease. The sending of bulletins will resume in October. 

“Through monitoring, Epagri is helping technicians and farmers carry out the best management to control soybean diseases, aiming to achieve the environmental and economic sustainability of the activity”, concludes Eduardo.