Saving with copper wire from late blight on tomatoes - myth or reality: full analysis

Late blight is a disease that annually destroys crops in hundreds of areas. The disease is especially dangerous for nightshade crops, including tomatoes. To save tomatoes, gardeners use many methods, even such exotic ones as using copper wire.

But does this method work in practice? And if so, how to properly use wire to protect the crop from late blight? You will find detailed answers to these questions in our article.

What is the nature of the disease

First of all, let's figure out what late blight is. The causative agent of the disease is the fungal organism Phytophthora from the genus of the same name.. There are many varieties of these fungi, but the most dangerous and also the most common is Phytophthora infestans.

Late blight is capable of destroying the harvest of all nightshade crops on the site in one season - potatoes, tomatoes, eggplants, peppers. Sometimes it moves to strawberries, and if you are especially unlucky, even to garden trees, in particular apple trees.

Late blight affects absolutely all plant organs - from flowers to roots. Cracks and spots of black rot form on them. Through cracks, secondary infection occurs with other types of fungi and pathogenic bacteria.

Fruits affected by late blight lose their marketable appearance, quickly rot, have an unpleasant taste and are not stored. Advanced forms of late blight end in the complete death of standing plants.

Effect of copper

It is known that copper and most fungi are not compatible with each other. Copper compounds quickly and effectively destroy mycelium cells, destroying the entire colony. This is the basis for the action of such proven antifungal drugs as a solution of copper sulfate (copper sulfate) and Bordeaux mixture (sulfate with the addition of a lime suspension).

And as a result, many gardeners came up with the idea: if copper kills fungi, maybe it’s worth using “heavy artillery,” that is, pure copper? And experiments began with pieces of copper wire.

It can be useful:

How to treat tomatoes with iodine against late blight

How to apply late blight serum on tomatoes

Copper sulfate against late blight on tomatoes

Copper wire against late blight - myth or reality

Let's say it straight: agronomy is wary of the use of copper wire. This method of combating fungi is not officially recognized as effective. Moreover, in some cases, punctures of leaves and stems with wire can lead to the death of the plant or the entry of non-fungal pathogens into the wound.

This method of struggle was first described in the popular book “Advice for Gardeners” by A. I. Spiridonova and E. A. Chenykaeva back in 1974. No serious experiments were carried out in the USSR or Russia, and foreign ones gave results that do not allow us to clearly recognize the method as useful or ineffective.

At the same time, copper cannot be called completely useless.. In air, it gradually oxidizes, and its compounds and ions, together with the movement of juices, are spread throughout the tomato bush. Phytophthora cells penetrating into tomatoes may eventually die.

Another thing is that In this case, it is impossible to even approximately calculate the amount of copper entering the plant, which means cases of overdose are quite likely. And copper – we must not forget about this! - quite poisonous for humans, and it is of little use to the plant in such quantities.

Important. The use of copper wire can only be considered as an experimental auxiliary method of protection against late blight. A banal solution of vitriol will be much more useful, and modern fungicides will even give the wire a hundred points ahead.

Application of copper wire in practice

First of all, it's worth remembering: wire is used only for mature plants on which all the ovaries have already formed. Injuring young bushes is absolutely unacceptable: crop losses will be comparable to those caused by late blight itself.

To protect against late blight copper wire is used in several options:

1. Like a garter for the stems. Even if the preventive benefits are questionable, tying with copper wire is much more convenient than, for example, synthetic material: the wire bends easily, firmly fixes the plant without further injuring it, and at the same time does not decompose over the summer, like, say, jute twine - therefore one and the same garter can be used for many years in a row.
2. Piercing the bases of the trunks with pieces of thick wire. The most questionable use case, the effectiveness of which has not been proven.
3. Root tying. This method was developed in Germany. In this case, when planting seedlings, a ring is formed from copper wire in the soil, inside which the bush is planted. A wire with a cross-section of about half a millimeter and a length of about 50 cm is used.
4. Placing a piece of copper in the hole when planting seedlings. Theoretically, it should work; in practice, gardeners differ diametrically in their assessments of the effectiveness of this method.

How to use copper wire correctly

In order for copper wire to have the maximum preventive effect, follow a few simple rules:

1. The impact of the wire should be minimally traumatic for plants. The best option is to tie it with wire, tie the roots and put it in the holes. It is better to refrain from punctures.
2. If you choose to pierce the stems, choose only mature bushes. Puncture at the seedling stage, as many practice, leads at best to inhibited plant development.
3. When piercing, the ends of the wire should not be wrapped around the stem - this will interfere with its growth. If the wire interferes with caring for the plant, it is better to shorten it and bend the ends down.
4. Use wire that is free of oxide film on the surface and insulation. Remove the insulation, and clean the piercing “skewers” ​​themselves with sandpaper or a sharpening stone until shiny.

Read also:

How to save tomatoes from late blight if they are already sick

How and with what to treat tomatoes against late blight in open ground

Prevention from late blight using copper wire

In theory, Prevention of late blight using copper wire is as follows:

1. Under the influence of juice in the stems, copper enters into chemical reactions with plant components.
2. Copper compounds and ions are distributed throughout the tomato bush with a current of nutrients.
3. When the fungus tries to start forming a colony, copper compounds inhibit the growth of its cells, and late blight dies.

This method itself looks quite dubious.. The oxide film that forms on the surface of the copper does a good job of isolating the bulk of the metal from contact with the cells of the tomato plant - and as a result, very little copper enters the plant.

In addition, fungicides containing copper act in a contact manner - they do not penetrate into the plant, but form a film on its surface.

Important: In most cases, saturating a tomato plant with copper ions using a wire is similar to treating iron deficiency anemia in a person using nail piercings. Medicine does not recognize such treatment. But it is possible that this may help some individuals.

Gardeners' opinions

As with any controversial method, the opinions of practitioners are diametrically opposed. That's just several reviews on the use of copper wire as a prophylactic against late blight:

• “I’ve been piercing tomatoes with thin wires for about 12 years now. Until now, there has never been a single outbreak of late blight on them. But on the potato bushes growing nearby, no, no, it happens.”
• “I use wire, but it’s not a panacea. If you rely only on her, the harvest will die. Additionally, I observe crop rotation, once every five years I treat the area with a strong solution of vitriol, and for watering in the summer I use Fitosporin.”
• “Late blight has affected all the bushes in the open ground. To save the tomatoes at least in the greenhouse, I pierced all the plants with copper skewers. There was not a single case of the disease."
• “I use wire, but I can’t understand whether it is useful. There is no late blight - but the neighbors don’t have it either, but they don’t pierce it with copper, they water it with fungicides.”
• “The method doesn't work! I read about it in a magazine, tried it in a greenhouse, but I still had to destroy all the bushes!”
• “Noodles on the ears of gardeners and obscurantism! Tomatoes absorb copper only in soluble forms - and it is not the acid that circulates in the stems to dissolve the wire. Vitriol is even more useful.”

Important. The full range of reviews of this practice is intentionally presented here. Whether to use the method or not is up to everyone to decide for themselves.

Additional tips for treating the disease

It is more difficult to treat late blight than to prevent its occurrence. Therefore, even in cases where wire is used, punctures or garters are made not when late blight has already begun, but in advance, even before the main outbreak of the disease.

Don't forget about other measures:

1. Modern microbiological preparations work well as a measure to protect tomatoes from fungus. For example, Fitosporin is good in its various forms. Its advantage is that it is based on a culture of living soil bacteria - which means an overdose is extremely unlikely, the excess bacteria will simply die.
2. Synthetic fungicides “HOM”, “Ordan”, etc. are also effective.
3. Avoid dampness and thickening of the beds. No preventive measure will help if favorable conditions are created for the development of late blight.
4. Use rotted straw to mulch the beds. It contains Bacillus subtilis, a beneficial bacterium that inhibits fungi and pathogens.
5. Careful adherence to crop rotation is the most important condition for a good harvest!

Preventing late blight is much easier than curing it. And copper wire is only part of the preventive measures.

Conclusion

The use of copper wire against late blight on tomatoes is an extremely controversial method.And in any case, it cannot be the only method of control: copper does not replace preventive measures and the use of modern fungicides.

Whether it is worth getting involved with copper skewers and ties at all is up to each gardener to decide for himself: the opinions of practitioners on this issue are diametrically opposed.