Content
Destructive 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 unnoticed. To properly deal with it, you need to have a good idea of what we are dealing with.
The disease late blight is caused by a mushroom-like organism from the oomycete class. They are composed of various physiological races and biotypes. Their degree of aggressiveness towards tomatoes and potatoes varies from weak to very strong. Variability within a population phytophthora very large. This is what prevents the creation of varieties of tomatoes and potatoes 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 and severity of an infection depends on the following factors:
- Soil and climatic zone in which the suburban area is located. In different zones, the possibility of developing the disease is different. The likelihood of phytophthora 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 occurs.
- The time at which the disease first manifested itself. The earlier this happened, the more serious the consequences for tomatoes and potatoes will be, up to a complete loss of the crop.
- The resistance of the variety is an important indicator. Resistant tomato varieties resist disease longer and therefore allow for a larger harvest.
- Protective measures: treatment of planting material of tomatoes and potatoes and preventive treatments with chemical and microbiological fungicides help to contain the disease and prevent it from spreading. A fairly effective remedy is copper wire for tomatoes from late blight.
Phytophthora has the following development cycle:
Pathogens of phytophthora primarily affect potatoes. They can be found on the planting material, and there are especially many of them on the 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 the 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 germination stage. With an average defeat of potatoes by late blight, up to 8x10 in 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 an embryonic 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 quite long distances by the wind. In high humidity, the water droplets on the tomatoes help the spores to 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, to protect them from fogs, to water it yourself, and not to charge it with 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 it is unrealistic to comply with this condition in summer cottages. Therefore, in order to protect tomatoes from disease, it is first of all necessary to treat and prophylactically process potatoes.
Tomatoes also need to prevent late blight.
Measures to reduce the risk of tomato disease
- Choose early-ripening tomato varieties for planting, which have time to harvest before the onset of the disease.
- Give preference to the most disease-resistant tomato varieties.
- Process tomato seeds before sowing and seedlings before planting.
- Observe the crop rotation. Do not plant tomatoes after potatoes and other nightshade crops.
- Try not to allow 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 late blight.
- Protect tomatoes planted in open ground with temporary film shelters from rain, fog and cold dews.
- Feed tomatoes correctly, improve their immunity. Healthy and strong tomatoes are the last to get sick, so you need to not only grow high-quality tomato seedlings, but also follow all the rules of agricultural technology and avoid stress in plants.
- Tear off all leaves from tomatoes below the brush with fully formed fruits. The farther the leaves are from the soil, the less likely it is that the pathogen will get to them. For the same purpose, mulching of the soil around the tomato bushes with a layer of dry hay is carried out. When it overheats, a hay stick 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 a copper wire against late blight on tomatoes.
Role of copper in plant life
Copper is one of the trace elements that all plants need. The need for it in different cultures is different. Its content in plants is small. If we dry the green mass of various plants and investigate the copper content in it, we 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 a part of many oxidative enzymes, with its help the intensity of respiration is increased, 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 her, tomatoes, like other plants, become more resistant to various diseases, including fungal ones.
Copper can be applied as micronutrient fertilizer. But if you need to simultaneously increase the resistance of plants, the best way out is copper wire from late blight on tomatoes.
How to apply copper wire
The copper cable is stripped from the plastic sheath. This can be done mechanically or by calcining. 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, they 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 downwards. 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 also increase their yield.You can make a kind of 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.
