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Onion downy mildew

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Onion downy mildew

Fungus

What is an opportunist?

An "opportunist" is a population (fungi, bacteria, insects…) that takes advantage of a favourable environment to settle in, multiply and feed on it. It often develops when the natural defences of the affected organism are weakened — for genetic reasons or linked to context (water stress, deficiencies, nutritional imbalances, overcrowding…). This is typically the case in monocultures, where a single host plant, uniform and present in large numbers, offers ideal ground for it to spread.

Identification key : Downy mildew and late blight (oomycetes) (Damage and symptoms on the host)

Scientific name : Peronospora destructor

Other names : Downy mildew of onion

Oomycete of alliums, mainly onion and shallot, also reported on garlic and leek. Leaves show pale elongated patches covered in the morning by a greyish-violet growth, then bend over and dry; bulbs stay small. It can persist in infected bulbs and in the soil.

Crops affected : Garlic, Leek, Onion

Source : Peronospora destructor (PERODE)[Overview] — EPPO Global Database — EPPO

This page lists the bio-preparations in the collection that other references associate with this opportunist: Onion downy mildew.

Warning: the associations between recipes and opportunists come from other references (traditional practices, publications, user feedback). They are neither a recommendation nor a claim of effectiveness. There is no certainty regarding the preparation, application and use of these bio-preparations. See the regulations

No published recipe is associated with this opportunist yet.

See also

Crops

Garlic Onion Leek

Opportunists of the same crops

Thrips Leek moth Onion fly Leek and garlic rust Tomato spotted wilt virus Brown spot of pear (Stemphylium) Rust Downy mildew Cotton bollworm (Helicoverpa) Chilli thrips Stolbur (bois noir)

← Referenced opportunists

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