November 14, 2012
First Two Cases of Soybean Rust Reported in Brazil
Scientists in Brazil reported that the first two cases of soybean rust this growing season have been confirmed, one case in Mato Grosso and one case in Santa Catarina. In both cases, the disease was discovered in volunteer soybeans that were growing along the roadside. They have been worried that soybean rust could make an early appearance in commercial soybean fields of Brazil this growing season because of the record number of volunteer soybean plants found along the state's highways that were infected with the disease.
If the disease is present on volunteer soybeans growing along the side of the field, it's only a matter of time before it moves into the newly planted soybeans. Dryer than normal weather during October probably slowed the spread of the spores from the volunteer soybeans to the commercial fields, but now that the rainfall has picked up, it will make it easier for the spores to spread out across the countryside. There have not yet been any reports of farmers applying a preventative application of fungicide, but in the areas where the disease has been confirmed, farmers will probably now start to apply fungicides.
It remains to be seen how severe the disease may be this growing season. It is not a good sign that the disease has already been confirmed during early November. Having to already apply fungicides during the month of November will drive up the cost of production for farmers and it will also increase the possibility that the disease will potentially impact soybean yields.