Downy mildew pathogen (examples: Peronospora species, Plasmopara species, Bremia species)

Downy mildew pathogens are a diverse group of oomycete microorganisms (not true fungi) that are obligate parasites of living plant tissue. They infect a broad range of crops and ornamentals, causing some of the world's most destructive plant diseases and leading to significant agricultural losses worldwide. Downy mildew species are highly host-specific, and a single species will often only infect a narrow range of related plants. Typical symptoms include angular yellow spots on leaf surfaces, downy patches of sporangia on leaf undersides, and rapid destruction of foliage under wet, cool conditions. Common genera responsible for downy mildew include Peronospora, Plasmopara, Bremia, Pseudoperonospora, and Sclerospora. Traditional management relies on resistant plant varieties and cultural practices, with limited chemical options due to resistance and safety concerns. Molecular diagnostic tools are increasingly important for species identification and monitoring.

Other names

Downy mildewDowny mildew oomycetesDowny mildew pathogensOomycete pathogens (downy mildew)

Inhibition of sporangia/zoospore development in oomycetes (protectant/curative fungicides); Disruption of cell wall synthesis or mitochondrial function in oomycetes