São Paulo prepares to combat the wood wasp
New reports of the presence of the pest in the State raised the alert and meetings have already been held between entities and producer associations
19.12.2023 | 16:10 (UTC -3)
The occurrence of Asian rust (caused by Phakopsora pachyrhizi) is on the rise in Brazil. According to data from the Antirust Consortium, led by Embrapa, current records exceed the average number of occurrences over the last five years by more than 200%. Among the reasons given by the research institution for this increase, emphasis is placed on the fact that the South region had a less severe winter, favoring the emergence of voluntary soybeans, which in turn already had inoculums of the disease.
To make matters worse, the greater distribution of rain, interspersed with dry spells, the effects of the El Niño climate phenomenon, has caused difficulties in establishing the crop, with delays in planting and the need for replanting in several locations.
“This scenario becomes very favorable for the occurrence of Asian rust, the most aggressive disease we have in soybean crops, which can cause losses of up to 90% if not controlled, according to Embrapa. This harvest we already have reports of the disease symptoms occurring very early in the states of Paraná, Rio Grande do Sul, São Paulo and in neighboring countries such as Paraguay and Bolivia”, says Carlos Toscano, agronomist and manager of the national fungicide portfolio. for soybeans at Bayer.
Until December 17th, Paraná leads in the number of registered occurrences of the disease in the country, with 72 cases. Of the 60 municipalities in the state affected by rust, the regions with the most cases are Toledo, Santa Terezinha de Itaipu, Guarapuava, Corbélia, Candói and Cascavel. Next comes Rio Grande do Sul with 11 cases, Santa Catarina with 4 cases, São Paulo with 3 and Mato Grosso do Sul with 1.
Management against the disease
According to Toscano, the farmer's focus at this moment is to adopt the best fungicide management strategy, always attentive to the challenges that this disease brings. “We recently launched a new fungicide, Fox Supra (see information here), which combines prothioconazole in its formulation with the new carboxamide, impirfluxam”, says the agronomist.
Toscano highlights some important measures to reduce damage:
• Use the direct planting system with crops that help cover the soil with straw.
• Respect the sanitary void period.
• Within an agronomic limit, sow earlier to avoid the times most favorable to diseases.
• Use chemicals preventatively.
• Choose effective chemical products, with assertive doses to control the main soybean diseases, such as Asian rust, target spot, white mold and grain rot.
• Choose soybean varieties that have tolerance to some of these problems.
• Use of digital tools that contribute to effective monitoring and control in affected plots.
“It is worth the producer's attention to adopt good practices, such as respecting application intervals of up to 14 days; associate systemic fungicides with multisites; and use volume of syrup and product doses as recommended in the leaflet and always looking for the best application technology (within the best times of the day)”, concludes Toscano.
More data on Asian rust
The articles listed below contain more information about the disease:
• Chemical control of Asian rust in soybeans.
• Resistance of Asian rust to the application of pesticides.
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