DiseaseDowny mildew control

Bicarbonate & plant extracts against downy mildew control

The effectiveness, measured

55 /100

Time horizon: Immediate

Why it works

Some extracts and oils give a contact reinforcement against downy mildew, useful to ease reliance on copper.

What to measure for this pairing

Copper replacedDowny-mildew severity

Why this problem matters

Downy mildew (Plasmopara viticola) is the disease that pins the organic grower hardest. Without systemic synthetic fungicides, defence rests on copper and contact products, which only protect what they cover — forcing you to treat ahead of infection and renew after rain.

Management lives on a tension: protect the vineyard without exceeding the EU copper cap (28 kg/ha over 7 years). That means treating at the right moment, at the minimum effective rate, backed by risk models and rigorous logging of every application.

Problem indicators

Copper applied (kg/ha, 7-yr mean)Recorded infection periodsTreatments per seasonLeaf / cluster area lost

Certification & rules: Central to organic status and the EU copper cap — audited at certification.

How to apply the means

  1. 1Fit them into the programme as reinforcement and rotation.
  2. 2Apply preventively, with good coverage.
  3. 3Reapply frequently (short persistence).
  4. 4Log them as part of the phytosanitary programme.

Frequently asked

Does bicarbonate replace sulfur?

Not entirely — it is mostly a complement and alternative in specific windows, helping to reduce and rotate with sulfur.

Are all extracts allowed in organic?

No. Only those on the authorised-input lists — which is why logging by active substance is essential.

Same means, other problems

Same problem, other meansDowny mildew

Related reading →Copper in organic viticulture: the limits, the maths and how to stay under them

How GrapeFlow helps

The proof organic certification demands — logged by plot and date.

Phytosanitary register with authorised inputs

Every treatment logged with product, rate and active substance, flagging what is allowed under organic rules — an audit-ready history.

Downy & powdery mildew risk models

Per-plot disease risk from local weather, to treat at the right moment and spend less copper and sulfur.

Electronic field notebook

All operations — weeding, green manure, biocontrol — logged by plot and date, ready for organic certification.