Researchers find Asian rust in RS and SC in September 2023

Asian rust uredia (caused by Phakopsora pachyrhizi) were identified in volunteer soybeans in analyzes at the phytopathology laboratory of the Federal University of Fronteira Sul (UFFS), Erechim campus. The information is from the teacher Paola Mendes Milanesi (left in photo).

According to his assessment, "the scenario is worrying, since soybean sowing has not yet begun in Alto Uruguai Gaúcho. And the disease is already present. This indicates that in this harvest Asian rust will be a very evident disease in soybean crops and requires attention".

Considering this scenario, the researcher Alana Tomen (right in the photo), from Proteplan, alerts to the situation in Mato Grosso. "The period between the last rain of the 22/23 harvest and the mango rains in MT was at least 50 days shorter than in the previous four years", he explains. This creates good conditions for the "green bridge". According to Alana, "it is better to prevent, carry out good desiccation, anticipate the first application of fungicides".

This implies "including efficient active ingredients for this target in the program, adding multi-site fungicides in all applications and monitoring the plots very carefully", he explains. Once the disease is detected, adds the researcher, "inserting morpholine is a good curative management strategy."

To date, cases of Asian rust have been reported in the municipalities of Erechim, Mato Castelhano, Não-Me-Toque, São Sepé and Tupanciretã (all in RS); and in Campos Novos (in Santa Catarina).

The results of the latest research trials with fungicides for the control of Asian rust (fungus Phakopsora pachyrhizi) can be seen here: "Fungicide effectiveness: see the numbers from the 2022/23 trials".