Crop-Free Periods Adopted by Brazilian States to Control Pests

The vast majority of grain producing states in Brazil have adopted a period of 60 to 90 days during which soybeans, cotton, or dry beans are not allowed to be grown. Since most of Brazil does not have cold winter time temperatures that can control pests from one growing season to the next, the goal of these programs is to minimize the spread of diseases and pests by eliminating host plants during the off season.

In the case of soybeans, the goal is to reduce the spread of soybean rust, which was introduced into Brazil during the 2000/01 growing season and has cost Brazilian farmers billions of dollars in lost production and additional control costs. Soybean rust spores can remain viable for a maximum of 55 days without the presence of a host plant so the goal is to eliminate any soybean host plants for a period of 60 to 90 days. In most states, the soybean-free period is 90 days, but some states had adopted a 60 day soybean-free period.

The soybean-free program was established in 2006 in the states of Mato Grosso, Goias, and Tocantins and it has since been adopted in 12 Brazilian states. During the 60 or 90 day period, farmers are not allowed to grow any soybeans and they must also eliminate any volunteer soybeans that may have germinated on their property. Grain handling facilities and transportation companies are also required to eliminate any volunteer soybeans on their property as well. If a property owner is determined to have not made a good faith effort to eliminate volunteer soybeans, he can face significant fines.

In the center-west region of Brazil, the soybean-free period usually starts in early to mid-June and concludes in mid to late September. In northeastern Brazil, the soybean-free period usually starts later in mid-August and extends into October.

Neighboring Paraguay, which borders on Mato Grosso do Sul and Parana, also adopted a similar program in February of 2011 and their soybean-free period starts June 1 and terminates August 30.

A similar prohibition period has been adopted for dry bean producers to help control a pest known as the white fly. The insect not only survives on plant juices, it also transmits the mosaic virus which can have a significant impact on dry bean production. Only the state of Minas Gerais and the Federal District has thus far adopted an official dry bean-free period which is generally during September and October.

Some states have also adopted a cotton-free period to help control the boll weevil. The cotton-free period and they can vary by region, but it generally occurs from early August to late November.

For all these crop prohibition periods, the only exception is made for scientific research or seed increases and in these cases; the fields are closely monitored for diseases and pests which are controlled as best as possible.