Fluopyram is a fungicide that protects various crops from fungal diseases. This active ingredient belongs to the chemical class of pyridinyl ethylbenzamides and is specifically categorized as a succinate dehydrogenase inhibitor (SDHI). It provides robust protection, contributing to healthier plants and improved agricultural yields.
How Fluopyram Works
Fluopyram inhibits succinate dehydrogenase (SDH), an enzyme in the fungal mitochondrial respiratory chain. This targets Complex II, blocking electron transport and preventing fungi from generating energy for survival. This interruption stops fungal growth and leads to death.
It impacts multiple developmental stages of fungal pathogens, including spore germination, germ tube elongation, mycelial growth, and sporulation. This comprehensive inhibition contributes to its broad-spectrum efficacy against many fungal diseases. Once applied, fluopyram exhibits translaminar activity (moving through leaf tissue) and systemic movement within the plant’s xylem, providing internal protection.
Where Fluopyram is Used
Fluopyram is extensively used in agriculture to protect a diverse range of crops from fungal and nematode threats. It is widely applied to fruits such as apples, grapes, and strawberries, and vegetables including potatoes, carrots, and cucurbits. Field crops like sugarbeet, dried beans, and cotton also benefit.
It targets a broad spectrum of fungal diseases, including powdery mildew, gray mold (Botrytis cinerea), apple scab, Alternaria species, Sclerotinia, and Monilinia. It is also effective against leaf spots, early blight, and anthracnose. Beyond fungal control, fluopyram acts as a nematicide, suppressing plant-parasitic nematodes, especially root-knot nematodes (Meloidogyne spp.).
Fluopyram is applied through various methods, including foliar sprays using ground, airblast, or aerial equipment. It is also used as a seed treatment for early-stage protection against soil-borne pathogens and can be incorporated into soil drenches and drip irrigation systems. This versatility, combined with its systemic movement and long-lasting residual effect, makes it a valuable tool in integrated disease management programs.
Impact on Health and Environment
Fluopyram is approved for use in numerous agricultural markets, including the European Union and the United States, with initial U.S. Environmental Protection Agency (EPA) approval in 2012. Regulatory bodies like the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) have also approved it, highlighting its compliance with international food safety standards. It exhibits low acute toxicity when exposed through oral, dermal, or inhalation routes and is not considered a skin or eye irritant or sensitizer.
While high doses in animal studies have shown effects on the liver and thyroid, fluopyram is classified as “not likely to be carcinogenic to humans” at typical exposure levels because its mode of action for these effects is considered non-genotoxic. It has been determined not to be genotoxic or mutagenic. Maximum Residue Limits (MRLs) are established for fluopyram in various commodities to ensure residues in food remain within safe consumption levels, underscoring that risks are minimal when used according to label instructions.
Fluopyram’s degradation in soil varies depending on soil type, with half-lives (DT50) ranging from approximately 21 to 386 days in European soils and 24 to 539 days in U.S. field sites. It is considered moderately mobile in soil, exhibiting high adsorption to soil particles and low leachability in many soil types, which limits its movement into groundwater. While some potential for water contamination through runoff or leaching exists, the risk is low due to its binding properties.
It is expected to be more persistent in water-sediment environments and can remain stable under anaerobic aquatic conditions. Assessments by Health Canada’s Pest Management Regulatory Agency (PMRA) indicate a negligible risk to non-target organisms like soil organisms, bees, beneficial arthropods, fish, invertebrates, and aquatic plants. However, some research suggests that while certain concentrations may stimulate beneficial soil microbes, other studies observe potential for altering overall soil microbial community diversity.