Brazilian company IH has announced the release of SEIV, a fungicide formulated with prothioconazole and metominostrobin for the management of target spot (Corynespora cassiicola) and other foliar diseases in soybean crops.
SEIV was developed in response to the growing incidence of target spot, which has increased by an estimated 33% over the past six years in Brazilian fields and can reduce yields by up to 40% in susceptible cultivars.
According to data from Conab, soybean growers in Brazil spend approximately USD 3.8 billion per season on fungicides. The pressures caused by disease have prompted higher adoption rates of targeted control: 71% of Brazilian soybean fields are currently treated for target spot, with particularly high rates (95%) in Mato Grosso, the country’s largest soybean-producing state.
SEIV combines two active ingredients — prothioconazole (a triazole fungicide) and metominostrobin (a strobilurin-type active) — formulated as a suspension concentrate (SC). The mixture marks one of the first commercial formulations to use metominostrobin specifically paired with prothioconazole in this format.
According to Archimedes Nishida, agronomist and product manager at IH, the formulation was designed to provide high systemic movement and stable absorption across the leaf surface. The SC formulation improves dispersibility in water and reduces the risk of leaf injury, compared to older solvent-based formulations, he noted.
″Metominostrobin offers high water solubility, which facilitates uniform coverage and rapid uptake,″ Nishida said. ″This characteristic helps maintain the active ingredient available within the leaf tissue for longer.″
Laboratory and field evaluations show that the combination of both active ingredients enhances activity against a range of pathogens, including Corynespora cassiicola and Phakopsora pachyrhizi (Asian soybean rust), due to their complementary biochemical targets — sterol biosynthesis inhibition (prothioconazole) and mitochondrial respiration inhibition (metominostrobin).
Field results and scope of use
Independent research institutions in Brazil reported SEIV achieved 95% control efficiency against target spot under test conditions, 80% against soybean rust, and 70% against late-season fungal diseases. Yield increases of around three 60-kg bags per hectare were observed in comparative trials.
Metominostrobin, used in SEIV, is known for its systemic mobility and capacity to move translaminarily within the plant, allowing more uniform distribution of the active ingredient. This property contributes to its residual activity when applied under high disease pressure and variable climatic conditions typical of the Cerrado and southern Brazil.
Additionally, the fungicide may be employed in preventive or early-curative programs and is compatible with integrated disease management (IDM) systems that include multi-site protectants and crop rotation.
Technical perspectives
Experts consulted during product validation emphasize SEIV’s chemical and formulation aspects as the main advances, rather than its novelty as a product.
Ivan Pedro, agronomist and researcher at Proteplan, said that incidence of increased disease has renewed the relevance of tools with broad-spectrum activity.
″Fungal leaf spots and rust have become major limitations for soybean yields,″ Pedro noted. ″Formulations that integrate different modes of action — while preserving selectivity — are valuable within crop rotation and anti-resistance programs.″
Marcelo Madaloso, plant pathologist at Madaloso Research, noted that recent research trends include exploring combinations centered on prothioconazole.
″The pairing of prothioconazole with metominostrobin is a recent step in formulation design,″ he said. ″The suspension concentrate helps moderate absorption into the leaf and reduces phytotoxicity risks, maintaining good selectivity and uniform activity against key foliar diseases.″
Disease management outlook
Of note, the increased occurrence of target spot and soybean rust across Brazil’s main production regions has heightened demand for mode-of-action diversity in disease management.
Most fungicides currently used for target spot were introduced more than a decade ago, and laboratory monitoring has identified pathogen populations with partial resistance to several chemical groups.
In this context, SEIV adds to the limited pool of new active-ingredient combinations being incorporated into rotation schemes, offering an option based upon complementary biochemical pathways and systemic behavior.
While results from independent trials show promising efficacy, pathologists emphasize the importance of integrating new fungicides into broader IDM programs to prevent premature resistance development.
With SEIV, IH aims to introduce an additional chemistry option targeting soybean foliar pathogens that have become increasingly challenging under Brazil’s humid and rain-favorable growing conditions.
Researchers suggest that broader adoption of integrated programs combining SC formulations, multiple modes of action, and precise application timing remains key to maintaining disease control and yield stability.
