All about Bordeaux Mixture

Bordeaux mixture is a fungicide used to protect plants, particularly vines, from fungal diseases such as downy mildew, powdery mildew, and blight. It is made by mixing copper sulfate and lime (calcium hydroxide) in water. Here's how you can prepare it:

Ingredients

- Copper sulfate (also known as bluestone): 100 grams

- Lime (hydrated lime or calcium hydroxide): 100 grams

- Water: 10 liters

Tools

- A bucket or container for mixing

- A wooden stick or a plastic stirrer (do not use metal)

- A scale for measuring the ingredients

- A sprayer for applying the mixture

Preparation Steps

1. Dissolve Copper Sulfate

- In a non-metallic container, dissolve 100 grams of copper sulfate in 5 liters of water. Stir the solution until the copper sulfate is fully dissolved.

2. Prepare the Lime Solution

- In a separate non-metallic container, mix 100 grams of hydrated lime with 5 liters of water. Stir well until you have a smooth, milky solution.

3. Combine the Solutions

- Slowly pour the lime solution into the copper sulfate solution while stirring constantly. This will create the Bordeaux mixture. The resulting liquid should be a sky-blue color.

4. Check the pH

- The pH of the mixture should be slightly basic (above 7). If the pH is too low (acidic), it can be harmful to plants. You can test the pH using litmus paper or a pH meter. If the mixture is too acidic, add a bit more lime to neutralize it.

5. Use the Mixture

- The Bordeaux mixture should be used immediately after preparation, as its effectiveness decreases over time. Pour it into a sprayer and apply it evenly to the plants you want to protect, ensuring you cover all surfaces, including the undersides of leaves.

Tips

- Apply Bordeaux mixture during the cooler parts of the day to avoid damaging the plants, and avoid using it when rain is expected, as it can wash off.

- Bordeaux mixture can stain surfaces, so be careful when spraying near buildings, garden furniture, or clothes.

- Use protective gear like gloves, goggles, and a mask when handling and applying Bordeaux mixture to avoid skin and eye irritation.

Storage

- Bordeaux mixture should not be stored for later use as it loses its effectiveness. Only prepare as much as you need for immediate application.