Bordeaux mixture is a mixture of:

Correct option is A

The correct answer is (A) Copper sulphate and hydrated lime

Explanation:
• Bordeaux mixture is one of the most famous and widely used fungicides in history.
• It consists of a solution of Copper Sulphate ($CuSO_{4}$) and Hydrated Lime (Calcium Hydroxide, $Ca(OH)_{2}$) mixed in water.
• It was discovered by P.M.A. Millardet in Bordeaux, France, in 1882.
• It is primarily used to control downy mildew, blights, and leaf spots in various crops like grapes, potatoes, and fruits.

Information Booster:
• The standard preparation ratio is often 4:4:50 (4 lbs Copper Sulphate, 4 lbs Lime, 50 gallons Water).
• It is unique because it is both effective and has strong tenacity (stays on the leaves even after rain).

Additional Knowledge:
• Slaked lime is essentially another name for hydrated lime, but in professional agricultural contexts, 'hydrated lime' is the preferred term for the dry powder form.
• Burgundy mixture: A similar fungicide where washing soda (Sodium Carbonate) is used instead of lime.
• Chestunt compound: A mixture of copper sulphate and ammonium carbonate used for controlling damping-off disease.