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January 10, 2020

Rust Monitoring System Reduces Fungicide Applications by 35%

Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.

Soybean rust was first discovered in Brazil during the 2000/01 growing season and since then, the disease has cost Brazilian farmers billions of dollars in control costs and lost production. The state of Parana generally has the most confirmed cases of soybean rust in Brazil and as a result, the state government has taken an aggressive approach in trying to monitor and control the disease.

According to the Secretary of Agriculture for the state of Parana, the state's extension service, Emater, has installed 248 collecting devices in approximately 200 municipalities across the state in order to monitor the presence of the disease. The system was put in place in 2016 in order to reduce the number of fungicide application needed to control the disease and it has resulted in a 35% reduction in the number of fungicide applications.

Parana is the only state in Brazil with this monitoring system that was originally designed in the 1970's to monitor wheat diseases, but has since been modified to monitor soybean rust. In areas without the collectors, fungicide applications are made based on the calendar without knowing if the disease is present in the area.

The collectors consists of a PVC pipe with adhesive tape that captures rust spores that can easily be circulating in the air. The tapes are then examined on a weekly basis by extension personnel from Emater and agricultural colleges. The results are published on state web sites, various aps, the local media and other methods.

Once the spores are present in an area, farmers are advised to closely monitor their fields to see if the disease has actually invaded their soybeans. The presence of spores does not necessarily mean that the disease has actually invaded the soybeans. In 2019, 50 collectors registered the presence of soybean rust spores even though the disease had not been identified in the soybean fields, which is the way the system was designed to work.

Parana's Secretary of Agriculture has indicated that various other states in Brazil have expressed interest in adopting the system for their state.