Bicarbonate & plant extracts
Contact complements to cut sulfur and copper.
Potassium bicarbonate and various plant extracts and oils are authorised contact means that complement sulfur and copper. Bicarbonate is effective against powdery mildew by altering the pH on the leaf surface.
Their role is mainly reinforcement and rotation — reducing dependence on sulfur and copper and helping in sensitive windows. They are strictly preventive/contact with short persistence, so they demand timing and reapplication.
Effort
Medium — needs frequent reapplication.
Cost
Medium depending on the product.
Time to result
Immediate but short-lived.
What it works against
Effectiveness by problem — click through for detail and metrics.
Potassium bicarbonate is effective against powdery mildew, allowing you to cut and rotate with sulfur.
Some extracts and oils give a contact reinforcement against downy mildew, useful to ease reliance on copper.
Certain extracts and salts reinforce botrytis prevention by making conditions less favourable to cluster infection.
How it works
Bicarbonate creates an environment hostile to the fungus on the surface; oils and extracts act by direct contact on fungal structures.
How to apply
- 1Fit them into the programme as reinforcement and rotation.
- 2Apply preventively, with good coverage.
- 3Reapply frequently (short persistence).
- 4Log them as part of the phytosanitary programme.
What to measure
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.
Related reading
Related means
How GrapeFlow helps
Apply and document this means by plot, with an audit-ready history for certification.
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.