How Asian Leaf Rust changed the paradigm of world grain trade
Before 2001, Brazil was a net importer of corn. Now, Brazil is the world’s #2 corn exporter. This dramatic change came about because of the procedures to control the fungus, Asian Leaf Rust (ALR), in the Brazilian soybean crop.
ALR was first reported in Brazil in 2001. Ever since 2001, epidemics of the disease have been common in Brazil, where the fungus can survive year‑round.
Also known as Soybean Leaf Rust (SLR) is an aggressive pathogen that has spread from Asia to Africa, South America, and the USA. Yield losses can be severe up to 80%.
For the most part, the climate in the US is too cold and too dry to provide a consistent year around environment to sustain ALR spores. Some years, the winds are just right and the ALR spores are swept from South America into the Lower Mississippi Valley. There have been a few cases of ALR as far north as Southern Illinois.