Entrevista Exclusiva - Manejo na fase inicial da planta evita perda na produtividade

March 5, 2026·27 min·2 clips

How can soybean disease mismanagement destroy your following corn crop?

1. Agrolink News features Sumitomo Chemical's Sérgio Chidi discussing disease management strategy for Brazil's 2025-26 soy and corn harvest season. 2. Sérgio Chidi is the fungicide and soy culture manager at Sumitomo Chemical; he is interviewed by host Flávia on the AgroLink News podcast. 3. The episode's core thesis is that soy disease management directly affects the sequenced corn crop, and that preventive early-stage fungicide applications are consistently undervalued by producers. 4. Asian rust in the 2025-26 season started in western Paraná on the Paraguay border and spread across the full state, into the south of São Paulo and Mato Grosso do Sul, then down to Rio Grande do Sul. 5. Later in the season rust reached Mato Grosso, Rondônia — specifically the Campo Novo dos Parecis region, which Chidi personally visited — and Bahia, areas not typically affected. 6. Chidi rates the national rust occurrence as within long-term averages but notes unusual unevenness caused by irregular rain in October and November, which staggered crop stages across regions. 7. The staggering of crop stages extended the window of disease exposure, causing rust to appear in northern regions during late harvest when it would normally have subsided. 8. Paraná and Rio Grande do Sul suffered the most severe rust damage because the disease arrived early in the crop cycle, when potential productivity losses can reach 80%. 9. Beyond rust, Chidi describes a full disease complex in soy including manchas-alvo (target spot), cercospora, diplodia, sercospora, rottenness of weeds, and anthracnose, noting that disease pressure is never limited to a single pathogen. 10. In corn, Chidi identifies bipolar as the dominant disease, alongside cercospora, diplodia, phosphoryl, and ferruginosa, and notes that the pest spodoptera moves between soy and corn, unlike most fungal diseases. 11. Chidi explains that pathogens in soy and corn do not cross-infect each other, but crop succession does interrupt disease cycles by removing the host from the environment. 12. He distinguishes necrotrophic fungi (which survive in plant residue/straw) from biotrophic fungi, noting that straw from one crop in the other's field reduces disease pressure from necrotrophic pathogens. 13. The optimum timing for the first corn fungicide application is V4 to V6, but most producers still begin at V6-V8 or V8-VT, which Chidi says results in measurably worse disease control outcomes based on field research. 14. Chidi attributes the rise of previously minor diseases like cercospora and septoria to the breeding industry prioritizing yield ceiling over disease tolerance, leaving high-potential hybrids more vulnerable. 15. Sumitomo's flagship fungicide Scalia Max combines Tebuconazole and Impifluxan, with Impifluxan described as the most effective carboxamide against rust and rottenness, and Tebuconazole as the best triazole for rust control. 16. A second product, Pladius, combines Impifluxan with Difenoconazole (triazole) and picoxitrobin (strobilurin), giving it greater selectivity for heat-sensitive cultivars and superior performance on target spot and cercospora. 17. Chidi describes Sumitomo's positioning strategy: Pladius in the vegetative phase and Scalia Max in the reproductive phase for rust-heavy regions, with the reverse position in target-spot-dominant areas. 18. The episode maintains a technical interview format with structured question-and-answer exchanges; the tone is informational with no debate or controversy. 19. Soy and corn producers in Brazil's major grain regions — particularly Mato Grosso, Paraná, Rio Grande do Sul — seeking to optimize fungicide programs will find this episode useful. 20. Listeners looking for broader agronomic content or non-Brazilian agricultural systems will find the highly region-specific disease and product detail of limited relevance.

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