en.Wedoany.com Reported - Rio Grande do Sul has implemented a mandatory soybean fallow period from July 3 to September 30, requiring that no live soybean plants exist in farmland during this period.
This phytosanitary measure aims to break the cycle of Asian rust, considered one of the most destructive diseases for soybean cultivation, causing significant losses to Brazilian growers. During the fallow period, growers must remove volunteer plants (locally known as "tigueras" or "guaxas") from planting areas, which spontaneously germinate after harvest and serve as hosts for the pathogenic fungus.
The core function of the fallow period is to prevent the fungus Phakopsora pachyrhizi from finding a surviving host during the off-season. With the disappearance of host soybean plants, spore counts in the environment will significantly decrease, thereby reducing disease pressure when planting the new season. This measure helps growers start planting under better sanitary conditions, reducing yield losses and improving plant protection efficiency. Lower disease incidence also reduces the number of fungicide applications, helping to maintain the effectiveness of these products over the long term.
Complying with the fallow period requires growers to continuously monitor farmland and remove any soybean plants that spontaneously emerge during this period. These volunteer plants act as a "green bridge" for Asian rust, allowing the fungus to survive until the next season. The state agricultural defense agency will conduct inspections and impose sanctions on violators.
This fallow schedule is part of the rules set by the Ministry of Agriculture (Ministério da Agricultura) for the 2026/27 season. States have established different fallow and planting periods based on regional climate and production characteristics.
The national fallow schedule is not uniform. States such as Mato Grosso do Sul, Bahia, and Tocantins also adopt this measure, but dates vary according to regional conditions and local agricultural calendars. Regionalization aims to make strategies against Asian rust more effective, allowing states to choose the most appropriate period to interrupt the fungal cycle without compromising the next season's planting plans.
After the fallow period ends on September 30, growers in Rio Grande do Sul can begin planting according to the official schedule set by the Ministry of Agriculture, starting the 2026/27 soybean season under more favorable phytosanitary conditions.
