What Is Bordeaux Mixture? Ingredients and Origin of the Classic Fungicide

Among the oldest and safest fungicides used in agriculture, the name “Bordeaux mixture” (also called Boóc-đô mixture in Vietnamese) holds a special place. It was the first chemical mixture ever used by humans to control plant diseases—and even today, Bordeaux mixture is still trusted in both organic and conventional farming.

1. What Is Bordeaux Mixture?

Bordeaux mixture is a fungicide made by mixing copper sulfate (CuSO₄) and hydrated lime (Ca(OH)₂) in water. When combined, these components create a contact-type fungicide capable of preventing and killing fungal spores on plant surfaces.

🔹 Other names:

• Bordeaux mixture (English)
• Bouillie Bordelaise (French)
• Thuốc Boóc-đô (Vietnamese transliteration)

🔹 Characteristics:

• Distinct sky blue–blue color
• Available as liquid or powder (in commercial formulations)
• Mainly preventive; has little curative effect once fungi have penetrated plant tissues

2. Ingredients of Bordeaux Mixture

The original formula of Bordeaux mixture is:
Copper sulfate (CuSO₄) + Hydrated lime (Ca(OH)₂) + Water

Depending on the crop and purpose, the mixing ratio can be adjusted, for example:

💡 Note: Always mix in the correct order (dissolve each component separately and then combine). If not, precipitation may occur and the fungicide will lose its effectiveness.

3. A Proud Historical Origin

📜 How was Bordeaux mixture invented?
In 1882, in the Bordeaux grape-growing region of France, botanist Pierre-Marie-Alexis Millardet noticed that:
Some vineyards painted with a mixture of lime and copper sulfate to deter thieves did not get infected by downy mildew, unlike other vineyards.

He then studied and refined the formula, creating what became known as “Bordeaux mixture”—the first widely used chemical fungicide.

🌍 Impact:

• Widely used worldwide since the late 19th century
• Laid the foundation for the development of many modern fungicides
• Still accepted in organic farming because its components are mineral-based (Cu + Ca)

4. Uses of Bordeaux Mixture in Agriculture

5. Advantages and Limitations of Bordeaux Mixture

✅ Advantages:

• Broad-spectrum action against many plant-pathogenic fungi
• Safe for humans and the environment when used properly
• Approved for use in organic farming (Organic certified)
• Low-cost, easy to prepare, suitable for smallholder farmers

⚠️ Limitations:

• Contact mode of action, non-systemic → preventive only, not curative
• Can burn young leaves if mixed incorrectly or sprayed in strong sunlight
• May cause copper buildup in soil if overused continuously
• Difficult to store if homemade; should not be kept overnight

6. Conclusion

Bordeaux mixture is a safe, economical, and sustainable fungicide suitable for both organic and conventional agriculture. With over 140 years of history, it has continued to prove its effectiveness and practical value—especially under Vietnamese farming conditions.

👉 If you are looking for an effective, affordable, and eco-friendly solution to prevent fungal diseases, Bordeaux mixture is definitely worth considering.