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Destroying a plant - this is the translation from the Latin name of the fungus phytophthora infestans. And indeed it is - if infection has already occurred, the tomato has little chance of surviving. An insidious enemy sneaks up unnoticed. To deal with it correctly, we need to have a good idea of what we are dealing with.
Late blight disease is caused by a fungus-like organism from the class of oomycetes. They consist of different physiological races and biotypes. Their degree of aggressiveness towards tomatoes and potatoes varies from weak to very strong. Variation within a population late blight very large. This is precisely what prevents the creation of tomato and potato varieties that are completely resistant to this disease. The causative agent of late blight changes faster than a new variety or hybrid of tomato or potato is created.
The likelihood of occurrence and severity of infection depends on the following factors:
- The soil-climatic zone in which the dacha plot is located. In different areas, the possibility of developing the disease is different. The probability of the development of late blight 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 period when the disease first appeared. The sooner this happened, the more serious the consequences will be for tomatoes and potatoes, including complete loss of the crop.
- Variety stability is an important indicator. Resistant tomato varieties resist disease longer and, therefore, allow you to harvest a larger harvest.
- Protective measures: treatment of tomato and potato planting material and preventive treatments with chemical and microbiological fungicides help contain the disease and prevent it from spreading. A fairly effective remedy is copper wire for tomatoes against late blight.
Late blight has the following development cycle:
Phytophthora pathogens primarily affect potatoes. They can be found on planting material, and there are especially many of them on tubers that remain in the ground from the previous harvest. There are also oospores that appear as a result of reproduction, which are able to survive the winter thanks to their 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 potatoes that are the first to be attacked by late blight. And if earlier the disease overtook it at the time of flowering, then modern aggressive races of the fungus can infect potato plants already at the seedling stage. With an average infection of potatoes by late blight, up to 8x10 to the twelfth power of sporangia are formed on the bush.At temperatures above 20 degrees, sporangia do not form spores, but germinate into the damaged plant through 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 wind over quite long distances. With high humidity, water droplets on tomatoes help spores penetrate 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, protect them from fog, water them yourself, and not leave it to the 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 disease, it is necessary to first treat and preventively treat potatoes.
Tomatoes also need late blight prevention.
Measures to reduce the risk of tomato diseases
- Choose early-ripening tomato varieties for planting that have time to produce a harvest before the onset of the disease.
- Give preference to tomato varieties that are most resistant to the disease.
- Treat tomato seeds before sowing and seedlings before planting.
- Maintain crop rotation. Do not plant tomatoes after potatoes and other nightshade crops.
- Try not to allow air temperature fluctuations in the greenhouse to avoid condensation on the film.Drops of condensation fall on the tomatoes and create conditions for the development of late blight.
- Protect tomatoes planted in open ground with temporary film shelters from rain, fog and cold dew.
- Feed tomatoes correctly and increase their immunity. Healthy and strong tomatoes are the last to get sick, so you need not only to grow high-quality tomato seedlings, but also to follow all the rules of agricultural technology and avoid stress in the plants.
- Pick off all the leaves of tomatoes below the cluster of fully formed fruits. The farther the leaves are from the soil, the less likely it is that the pathogen will reach them. For the same purpose, the soil around the tomato bushes is mulched with a layer of dry hay. When it overheats, Bacillus subtilis is formed, which is an effective remedy in fight against late blight.
- Carry out preventive treatments for tomatoes.
If you don’t have enough time for them, you can use a simpler, but quite reliable method. This is copper wire against late blight on tomatoes.
The role of copper in plant life
Copper is one of the trace elements needed by all plants. The need for it varies among different cultures. 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 and the metabolism of proteins and carbohydrates accelerates. Copper participates in the process of chlorophyll synthesis, 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 in the form of microfertilizer. But if you need to simultaneously increase the resistance of plants, the best solution is copper wire against late blight on tomatoes.
How to use copper wire
The copper cable is stripped of its plastic sheath. This can be done mechanically or by calcination. Next, cut the prepared wire into small pieces, no more than 4 cm. The wire thickness should not be less than 1 mm. When the tomato seedlings are planted and the stem has acquired a certain strength, carefully pierce it with a pointed piece of wire at a height of 7-10 centimeters from the ground. The ends of the wire should point down. Do not twist the wire around the tomato stem. Such piercing will not only ensure a constant supply of copper ions to the leaf apparatus of tomatoes, but will also increase their yield. You can make some kind of nails from copper wire.
You can watch the video to see how to do all this in practice:
If you can’t devote a lot of time to tomatoes, copper wire is the best preventive measure against late blight.
