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June 3, 2011

Soybean Free Period in Brazil Starts June 15th

In most of the major soybean producing states in Brazil the mandatory 90-day soybean free period will start on June 15th and run through September 15th. The prohibition was put in place a number of years ago as a way to slow the spread of soybean rust. No soybeans are allowed to be grown during this period and all volunteer soybean plants must also be destroyed. The only exception to the rule are soybeans grown for research purchases or for seed increase and they must be approved by state authorities.

The prohibition is aimed mainly at controlling volunteer soybeans in fields, along roadways, along railways, and storage facilities. In Parana for example, the fines for not destroying volunteer soybean can vary from R$ 50 to R$ 5,000 depending on the level of the infraction. In 2010, the authorities in the state of Parana issued 134 citations involving 4,236 hectares of land, 30 kilometers of roadways, and 190 kilometers of railways.

Soybean rust is the most serious disease that affects soybean production with losses as high as 80% if the disease goes untreated. The soybean rust spores can only survive approximately 60 days without a host plant. Therefore, the thrust behind the 90-day soybean free period is to eliminate as many of the host plants as possible during the dry season in Brazil in an attempt to slow the spread of the spores once the soybean planting begins again next September. Soybeans are the principal host plant for the disease, but other tropical legumes can also serve as host as well.

The areas where volunteer soybeans are the hardest to control are probably along roadways. Many of the trucks that transport soybeans in Brazil dribble out soybeans along thousands of kilometers of roadways and some of these soybeans germinate in the midst of the weeds along the roadway. Each landowner is responsible for destroying any volunteer soybeans that may be growing along the highway that borders their property because the vast majority of the roadways are not mowed.