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Destroying the plant – this is the translation from the Latin name of the fungus phytophthora infestans. And indeed it is – if the infection has already occurred, the tomato has little chance of staying alive. The insidious enemy sneaks up imperceptibly. In order to deal with it correctly, you need to have a good idea of what we are dealing with.
Phytophthora disease is caused by a fungus-like organism from the oomycete class. They consist of various physiological races and biotypes. The degree of aggressiveness in relation to tomatoes and potatoes varies from weak to very strong. The variability within the phytophthora population is very high. This is precisely what prevents the creation of varieties of tomatoes and potatoes that are completely resistant to this disease. The late blight pathogen changes faster than a new variety or hybrid of tomato or potato is created.
The likelihood and severity of infection depends on the following factors:
- The soil-climatic zone in which the suburban area is located. In different areas, the possibility of developing the disease is different. The degree of probability of late blight development in the Central and Central Black Earth regions is average, the most harmful pathogens live in the North-West, the Urals, Siberia, and the Far East.
- Weather conditions that accompany the growing season of tomatoes and potatoes. In dry and hot weather, the disease stops. With the onset of low air temperatures and high humidity, the peak of late blight disease occurs.
- The time when the disease first appeared. The earlier this happened, the more serious the consequences for tomatoes and potatoes will be, up to the complete loss of the crop.
- Variety stability is an important indicator. Resistant varieties of tomatoes resist the disease longer, and, therefore, allow you to harvest more.
- Protective measures: treatment of planting material of tomatoes and potatoes and preventive treatments with chemical and microbiological fungicides can contain the disease and prevent it from spreading. A fairly effective remedy is copper wire for tomatoes from phytophthora.
Phytophthora has the following development cycle:
Phytophthora pathogens primarily affect potatoes. They can be found on planting material, and there are especially a lot of them on tubers that remained in the ground from the last harvest. There are also oospores that appeared as a result of reproduction, which are able to survive the winter thanks to the protective shell.
Mow potato tops in advance and burn them so as not to leave a breeding ground for the disease on the site.
It is the potato that is the first to be attacked by phytophthora. And if earlier the disease overtook him at the time of flowering, then modern aggressive races of the fungus can infect potato plants already at the seedling stage. With an average defeat of potatoes by late blight, up to 8×10 to the twelfth degree of sporangia are formed on the bush. At temperatures above 20 degrees, sporangia do not form spores, but germinate into the damaged plant with a germ tube.
At low temperatures, each of the sporangia produces spores that form a huge cloud indistinguishable to the naked eye. Unfortunately, spores can be carried by the wind over fairly long distances. At high humidity, water droplets on tomatoes help spores to penetrate into the stomata of tomatoes and other nightshades, where they germinate, causing disease. Therefore, it is very important not to allow moisture on the leaves of tomatoes, to protect them from fogs, to water them on their own, and not to entrust this to rain, which will inevitably wet the entire plant.
If you follow the rules, the distance between planting potatoes and tomatoes should be at least one kilometer. It is clear that in summer cottages it is unrealistic to comply with this condition. Therefore, in order to protect tomatoes from the disease, it is first of all necessary to treat and prophylactically treat potatoes.
Tomatoes also need to prevent late blight.
Measures to reduce the risk of tomato disease
- Choose for planting early-ripening varieties of tomatoes that have time to give the crop before the onset of the disease.
- Give preference to varieties of tomatoes that are most resistant to the disease.
- Treat tomato seeds before sowing and seedlings before planting.
- Observe crop rotation. Do not plant tomatoes after potatoes and other nightshade crops.
- Try to prevent fluctuations in the air temperature in the greenhouse so that there is no condensation on the film. Drops of condensate fall on tomatoes and create conditions for the development of phytophthora.
- Protect tomatoes planted in open ground with temporary film shelters from rain, fog and cold dew.
- Properly feed tomatoes, increase their immunity. Healthy and strong tomatoes fall ill last, so you need not only to grow high-quality tomato seedlings, but also follow all the rules of agricultural technology and avoid stress on plants.
- Cut off all leaves from tomatoes below the brush with fully formed fruits. The farther from the soil the leaves are, the less likely it is that the causative agent of the disease will get to them. For the same purpose, the soil around the tomato bushes is mulched with a layer of dry hay. When it is overheated, a hay stick is formed, which is an effective tool in the fight against late blight.
- Carry out preventive processing of tomatoes.
If there is not enough time for them, you can use a simpler, but fairly reliable method. This is a copper wire against late blight on tomatoes.
The role of copper in plant life
Copper is one of the trace elements necessary for all plants. The need for it varies from culture to culture. Its content in plants is low. If we dry the green mass of various plants and examine the copper content in it, we will get a very small figure: from two to twelve grams per kilogram.
But despite this, the role of copper in the life of plants is great. It is part of many oxidative enzymes, with its help the intensity of respiration increases, the metabolism of proteins and carbohydrates is accelerated. Copper is involved in the synthesis of chlorophyll, increasing its content. And what is very important, thanks to it, tomatoes, like other plants, become more resistant to various diseases, including fungal ones.
Copper can be applied as a microfertilizer. But if you need to simultaneously increase the resistance of plants, the best way out is copper wire from phytophthora on tomatoes.
How to use copper wire
The copper cable is stripped from the plastic sheath. This can be done mechanically or by calcination. Next, cut the prepared wire into small pieces, no more than 4 cm. The thickness of the wire should not be less than 1 mm. When the tomato seedlings are planted, and the stem has acquired a certain strength, they gently pierce it with a pointed piece of wire at a height of 7-10 centimeters from the ground. The ends of the wire should look down. You can not twist the wire around the stem of the tomato. Such piercing will not only ensure a constant supply of copper ions to the leaf apparatus of tomatoes, but also increase their yield. You can make original nails from copper wire.
How to do all this in practice, you can watch the video:
If it is not possible to devote a lot of time to tomatoes, copper wire is the best preventive measure against late blight.