What is Bordeaux mixture?

What is Bordeaux mixture?

• A. A spray of copper sulfate, water and lime, developed by 1885 to prevent outbreaks of downy mildew.
• B. A sulfur-based spray to enhance grape color.
• C. A soil amendment to improve root uptake.
• D. A nutrient blend for vine growth.

Answer: (A)

Bordeaux mixture is a copper-based fungicide made from copper sulfate, lime, and water. It was developed in Bordeaux in 1885 to prevent outbreaks of grape downy mildew, caused by Plasmopara viticola. The copper ions on the leaf surface disrupt fungal spore germination and growth, providing a protective barrier. Lime helps stabilize the mixture, reduces copper toxicity to the plant, and aids in forming a adherent film on the leaf. Because it’s a contact fungicide, it should be applied preventively and repeated through wet periods to maintain protection. It’s not a sulfur-based spray for grape color, nor a soil amendment, nor a nutrient blend.

Bordeaux mixture is a copper-based fungicide made from copper sulfate, lime, and water. It was developed in Bordeaux in 1885 to prevent outbreaks of grape downy mildew, caused by Plasmopara viticola. The copper ions on the leaf surface disrupt fungal spore germination and growth, providing a protective barrier. Lime helps stabilize the mixture, reduces copper toxicity to the plant, and aids in forming a adherent film on the leaf. Because it’s a contact fungicide, it should be applied preventively and repeated through wet periods to maintain protection. It’s not a sulfur-based spray for grape color, nor a soil amendment, nor a nutrient blend.