Nov 09, 2009
Brazilian Soybean Farmers Working For Continued Success Against Soybean Rust
Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.
With an early start to the rainy season and the potential for increased pressure from soybean rust, Brazilian soybean farmers are watching their fields closely looking for any early signs of the disease. Soybean rust, which is caused by the fungus Phakopsora pachyritizl, appeared in Brazil in 2001 and has since spread to the entire soybean producing region of the country.
During the 2008-09 growing season, farmers in Mato Grosso applied on the average 2.5 fungicide treatments at a cost of R$ 40.00 to 50.00 per hectare. This includes the cost of the chemical as well as application costs and labor costs. In southern Brazil, the average application rate was 1.8 applications of fungicides during the last growing season. The cost of controlling the disease in Mato Grosso has improved considerably compared to three or four years ago when as many as six applications were needed to control the disease. Farmers and scientist accredit the improvement in controlling the disease to the implementation of a 90-day soybean-free period several years ago.
Without a host plant available, the soybean rust spores are viable for only about 60 days. Therefore, the idea of a 90-day soybean-free period was a way of breaking up the disease cycle. Since central Brazil does not have cold temperatures that could kill the spores, the way to break the disease cycle, at least temporarily, is to eliminate as many host plants as possible.
During the soybean-free period, farmers must inspect their fields and eliminate any volunteer soybeans that may have germinated. Grain elevators and grain processing facilities must also inspect their facilities and eliminate any volunteer soybeans. Officials from the state department of agriculture in Mato Grosso conducted nearly 2,800 inspections between June 15, 2009 and September 15, 2009 (the soybean free period in Mato Grosso) throughout the state looking for any escaped soybeans. If these soybeans are not eliminated, they can issue fines to the property owners, but only 76 citations were issued in 2009.
Unfortunately, in a tropical country such as Brazil there are many other type of plants that can serve as hosts.