Spraying grapes with Bordeaux mixture: autumn, spring, summer

Bordeaux mixture for grapes is one of the universal and effective remedies against numerous harmful bacteria. This liquid has become widespread throughout the world due to its properties.

Why treat grapes with Bordeaux mixture

To understand why a culture is treated with a liquid, its mechanism of action should be studied. Bordeaux mixture, falling on the leaves of grapes or a vine, penetrates into the juices of the plant. Microorganisms that feed on the culture receive a dose of poison, from which they die.

The pests treated with Bordeaux liquid die, the rest of the insects try not to approach the sprayed shrub

Composition of Bordeaux liquid for grapes

The main components of the drug are copper compounds, which are slightly soluble in water and thus provide long-term protection to the plant. The composition of the Bordeaux liquid for grapes contains copper sulphate and lime milk. When diluted, depending on the proportions, the substance looks like a suspension of a sky-blue color of varying intensity.

The chemical composition of the liquid will vary depending on the ratio of the components. If copper sulfate and calcium hydroxide are mixed in proportions of 2:1, then CuSO4 compounds are predominantly formed as a result. But if you gradually increase the amount of lime in the mixture, then copper oxide hydrate will form, which will affect the fungicidal actions of the substance.

If there is not enough Ca (OH) in the Bordeaux liquid, then an excess of copper sulfate is formed, which will burn the leaf plates of the plant. The protective properties of such a composition are low.

The maximum efficiency of a substance where copper sulfate and lime are combined in a ratio of 1: 0,75

Pros and cons of the tool

Any processing of grapes in the fall with chemicals has both advantages and disadvantages. When purchasing a Bordeaux mixture, its properties and application features should be adequately assessed.

Advantages:

• the agent, distributed over the surface of the plant, remains there for up to a month, performing protective functions;
• a wide range of actions;
• a positive result of use can be seen in a short time;
• the liquid does not damage the plant when used correctly;
• the substance is resistant to precipitation;
• economical consumption and ease of preparation.

Disadvantages:

• the diluted product has a shelf life of no more than a day;
• the greatest efficiency is only in freshly prepared Bordeaux mixture;
• the use of the drug requires compliance with the proportions and production instructions;
• improper use of the solution can destroy the grapes;
• medium-level toxic effects on humans and animals;
• When carrying out work, protective equipment must not be neglected.

How to dilute Bordeaux mixture for grapes

Unlike most drugs, the drug can be used in various concentrations. For grapes, Bordeaux liquid can be diluted as 1% or 3% substance.

1% solution

The first stage of preparation is the selection of containers: you need to find two clean buckets with a volume of 10 liters each. Suitable for both plastic and enameled dishes.

Algorithm cooking:

1. In 1 liter of warm water, heated to 30-50 ° C, dilute 100 mg of copper sulfate. The contents in the bucket must be thoroughly dissolved so that no crystals remain.
2. In the second bucket, mix 200 g of slaked lime with 5 liters of water. As the dry matter dissolves, the liquid gradually becomes milk of lime in color. As a result, no lumps should remain in it.
3. Strain the contents of each of the containers separately using burlap or gauze. In a bucket with copper sulphate, the volume of water must be brought to 5 liters.
4. Mix the contents of the containers. The result should be a Bordeaux liquid of a pleasant sky-blue hue.

It is necessary to pour a solution of copper into diluted lime, and not vice versa, since the latter protects the leaves from burning

The result should be a solution with an acidic or slightly alkaline environment. If the gardener doubts his actions, it is recommended to check the concentration of the liquid. With an excess of acidity, the grapes will slow down their growth. If you spray the leaves with a highly alkaline agent, then the effect of such treatment will be short-lived.

When mixing a solution of copper sulfate and lime, safety precautions should be observed

To check the level of acidity, it is enough to dip a litmus test into the Bordeaux mixture. Its color should be blue, not red. Among folk methods, another method is common: it is recommended to lower a nail or wire into the substance for 1,5 minutes. If they change color to red, then the acid level is exceeded.

3% solution

The algorithm of work is similar, but there are differences in the number of consumables. To obtain a 3% solution, it is necessary to use 300 g of copper sulfate and lime. Add 5 liters of water to each container with the substance and mix thoroughly.

When and how to spray grapes with Bordeaux mixture

The aimless and untimely use of the mixture can negatively affect both the growth and development of grapes, and the level of its fruiting. For maximum effect, certain rules must be followed.

Treatment of grapes with Bordeaux liquid in spring and summer

The first spraying should be done in the spring before the buds open. This stage of care will maximize the protection of the plant from microbes and pests.

A 3% solution should be prepared for the procedure, pour it into a sprayer. Subject to safety precautions, process the grapes before flowering. Bordeaux liquid should be applied evenly and abundantly so that it gets into all cracks and crevices where harmful microorganisms like to settle.

After spraying with the mixture, a bluish coating may remain on the leaves.

The protective effect lasts for a month, so in the summer the treatment should be repeated. The procedure is required using a 1% liquid solution.

Processing grapes with Bordeaux mixture in autumn

Most gardeners leave the plant to prepare for winter after harvest. But no less important stage of care is the autumn processing of grapes. First you need to trim the shrub, then spray it with a 3% solution.

Safety regulations

Like any chemical agent, Bordeaux liquid can be dangerous to the human body. It doesn’t matter if the gardener prepares the mixture or sprays the grapes in the spring before flowering, in late autumn, he must adhere to the rules:

1. Mandatory equipment steps are rubber gloves, a mask and goggles.
2. Clothing should be worn with long sleeves.
3. Do not rub your eyes or touch your face while working.
4. Spraying should be carried out quickly, in dry calm weather.
5. The presence of other persons during the procedure without protection is unacceptable.
6. Store the finished solution in a closed container, out of the reach of children.
7. If the substance gets on the skin or mucous membranes, quickly treat the affected parts of the body using running water. It is recommended to consult a doctor.

Common mistakes

Despite the instructions, gardeners can make the following mistakes when using Bordeaux liquid for processing grapes:

1. To irrigate the vines, it is best to use a sprayer. Thanks to him, you can process hard-to-reach places. The use of a broom or brush will result in excessive fluid consumption.
2. It is required to adhere to the work schedule so as not to harm the plant. Violation of the terms leads to the fall of the ovaries, damage to the grapes.
3. It is recommended to carry out all work in the early morning or before sunset. The weather should be dry and warm. Neglect of these rules can lead to leaf burn, a decrease in the effectiveness of treatment.
4. All work must be completed a month before harvest. All bunches of grapes must be washed under running water without fail.

Sometimes gardeners note that the solution has exfoliated. This reaction is the result of diluting the already prepared Bordeaux mixture. In this case, the grapes cannot be sprayed, the mixture should be prepared again, following the instructions.

If the gardener noticed that the shrub has slowed down its growth, and few ovaries have formed, then the risk of improper use of the mixture is high. This situation develops if the grapes are sprayed with a 3% solution at the beginning of the growing season. The maximum allowable concentration for spring processing is 0,7-1%.

Conclusion

Bordeaux mixture for grapes is an effective, affordable tool with a wide spectrum of action. To obtain the maximum effect, it is necessary to strictly adhere to the instructions, to process several times per season. An important stage of the procedure is the observance of safety precautions and the consideration of possible errors during the procedure.