Mixture: Bordeaux

Pulverized copper sulfate and hydrated lime are added directly to a filling spray tank while the agitator is running to ensure even mixing.

Bordeaux mixture is one of the most historically significant fungicides in agriculture, consisting of a combination of , quicklime (calcium oxide) or slaked lime , and water . First developed in 1882 by French botanist Pierre-Marie-Alexis Millardet to combat downy mildew in vineyards, it remains a staple in both conventional and organic farming due to its efficacy and low cost. Core Components & Chemical Composition

) results in a gelatinous, sky-blue suspension of copper hydroxide and calcium sulfate.

The final solution must be neutral or slightly alkaline (

Two primary methods are used for small-scale and commercial applications:

Separate concentrated solutions of copper sulfate and lime are prepared in non-metallic containers. These are then diluted and combined in a spray tank.

The mixture is traditionally prepared by dissolving copper sulfate in water and adding a suspension of lime. Mixing copper sulfate ( ) and lime (

); acidic mixtures are phytotoxic and can burn plant foliage.