Stains on tomato leaves (diagnostics and recommendations on what to do).
Content:
If some spots appear on the leaves of your tomatoes, this serves as a signal that something is wrong with them. If you carefully monitor your seedlings, then it will not be difficult to understand the reasons for their appearance. Various spots can appear not only due to infection with a fungal disease, but also due to a lack of some trace elements during feeding.
What can cause stains
The sooner you figure out the cause of the spotting, the sooner you solve the problem. Naturally, correcting the situation at the initial stage is much easier and safer for plants than solving this issue when the seedlings are in disrepair.
There are several situations due to which stains may appear on your tomatoes. And if they suddenly appeared, then this is a kind of signal that something is wrong with the tomatoes. Diseases on tomatoes generally appear very often, and they need to be treated immediately. Most often, spotting begins to appear not earlier than July. At this time, on tomatoes, as the rule, the fruits already weigh and are actively ripening, and very little time remains before harvesting. Basically, diseases begin to attack at this very time, because the weather is quite hot during the day, but the nights are already becoming colder and damp, and in the morning a large amount of ross falls out. And cold, dampness and dew are known to be an excellent environment for the rapid development of a fungus. As a rule, the fungus can destroy your plants and almost the entire crop in literally a matter of days, so the fight against it must be carried out immediately, as soon as you notice that something is wrong with the plants. It is the spots on the leaves of the tomato that make it clear that the seedlings are affected by the fungus, or there is a lot of tomato, or vice versa, there is very little of some nutrient that enters the plant itself through the root system. The reason may also be that the plants are not being cared for properly.
If your tomatoes are grown in a greenhouse, then spots may appear due to high humidity and a sharp drop in day and night temperatures. This is the first reason for the appearance of the fungus. The fungus begins to infect the plant from below and spreads very quickly throughout the greenhouse, and it multiplies by spores. It is due to the fact that the dampness in the greenhouse mainly exceeds the prescribed norm in it very often fungal diseases start.
How to understand what kind of disease
Depending on the disease or lack of some element, when feeding, the spots on the tomatoes always differ from each other. The spots are always different and thanks to this you can quickly determine the cause of their appearance and prevent it.
If almost immediately after transplanting seedlings into open ground, not uniform white spots appeared on the leaves of the tomato, but the plants themselves became very sluggish, then in this case, most likely the cause is a sunburn. Most often this happens when the seedlings were very little hardened before planting, or there was no hardening at all. It is in order that the plant that is already weak after transplanting does not suffer, and does not receive even more stress, the seedlings should always be hardened for two weeks before planting in order to accustom the seedlings to environmental conditions. And the transplant itself should be carried out either early or early in the morning, or better late in the evening, when the sun is already setting.But if, nevertheless, spots on the leaves have already appeared, then in the evening you can treat the plants with Epin or Zercon preparations, they will help the seedlings cope with stress and the leaves should quickly return to normal. But if this did not happen and the stain still remained, then the reason lies elsewhere and it must be urgently looked for without wasting precious time.
When a white bloom began to appear on the leaves of your seedlings, you will not have to guess for a long time about the disease - this is powdery mildew... This disease very often appears on completely different plants, and it is very dangerous for them. With powdery mildew, white spots appear on the leaf on both sides, after which they begin to fall off very quickly, and this, in turn, has a very strong effect on the crop, or rather on its loss. This disease appears mainly if the plant has little sunlight, but the humidity, on the contrary, is increased. It also very often appears when the seedlings grow very close to each other, and ventilation, respectively, between them practically does not pass. So that this dangerous disease does not appear and does not destroy all your work, it is imperative to take preventive measures.
It is also imperative to know that if this fungal disease does appear, then you need to fight it right away, because powdery mildew can literally ruin the entire tomato plantation in a day. With a small damage to the plants, it is necessary to immediately carry out the treatment with the appropriate preparations, and if some particular plant has suffered very badly, then it is better to pull it out of the ground and burn it. It is better to lose one seedling than to jeopardize all the others. After you remove diseased seedlings, the remaining plants need to be treated with fungicides or biological products. Their choice in gardening is simply amazing in its number.
If white spots with a dark brown border appear on the leaves, which began their lesions from the bottom and gradually move to the upper part of the plant, then this means only one disease - septoria. This disease in itself is very dangerous, so if it is not cured immediately, as soon as it appears, then soon the leaves will completely darken and quickly fall off. And the disease will continue to spread very quickly and infect the rest of the plantings. Initial infestation can occur because the land was poorly cultivated or not properly cultivated before planting. Or the spores of this fungus could have infected the seeds, and before they were sown in the soil for some reason, they were not disinfected. Although this action must be carried out before sowing. To do this, you just need to soak the seeds for a while in a weak solution of potassium permanganate. Most often, this disease begins its activity in the second half of summer, again when it is hot during the day and damp and cold at night. If you see that your leaves are affected, then immediately and without regret, cut them off and destroy, it is best if you burn them. By itself, this disease is very poorly treated, and only at the very initial stage it is possible to get rid of it using special drugs.
It happens that silver spots appear on the leaves of a tomato. This does not happen so often, and mostly only in greenhouses. Many gardeners unknowingly become very scared, although in fact it is not worth doing this. This is not a fungal disease, but rather an abnormality in the development of the plant. This mainly happens with low-quality seeds of hybrid varieties, and also a sharp temperature drop contributes to this. After all, starting in July, day and night, it is very different from each other. So if you see such spots on your tomatoes, then you shouldn't be scared at all, just carry out the treatment with anti-stress drugs and ventilate the greenhouse more often.And most importantly, know that if such spots appear, then nothing threatens your future harvest at all.
If the leaves of a tomato have become completely covered with spots of green and yellow, then they are overtaken by such a disease as mosaic. It can be noticed immediately, and it appears not only on individual leaves, but completely over the entire tops of a tomato, and you can notice it by a specific, unusual pattern. The younger the plant, the better this pattern is visible on them. This disease can very quickly infect the entire area where tomatoes are planted. This is a kind of virus carried by harmful insects. Also, this virus can easily be found in the ground, and you can also get it from untreated seeds before sowing. For the prevention of this disease, it is best to choose hybrid varieties, they generally have immunity from many diseases. But if, nevertheless, you decide to plant ordinary varieties, then be sure to carry out the seed treatment. But remember that if the plant is infected, then it is useless to treat it, especially at this time you endanger the rest of the seedlings. Affected plants just need to be pulled out of the ground and destroyed.
It also happens that yellow spots appear on the leaves of a tomato. Initially, they appear on the lower leaves of the plant, and then they crawl upward. This is the very first initial stage of such a fungal disease as cladosporium... Further, with this disease, in the place where spots have formed in the upper part of the leaf, a gray bloom forms from the bottom. And after that, the spots turn brown, and the leaves dry up and fall off. If you notice such spots on your tomatoes, then you need to immediately treat them with special preparations. If this disease is not cured in time, then your harvest will be less than half. Basically, this disease appears in those tomatoes that grow in a greenhouse. Even after you have harvested and removed all the plants, the fungus in the greenhouse persists for many years and will also affect newly planted tomatoes from year to year. In order to completely get rid of this disease and secure future plantings, it is necessary not only to cure the infected tomato bushes, but also to carry out a hollow disinfection of the greenhouse itself and the earth in it.
With the same success, brown spots may appear on the leaves of the tomato. They, like all the others, initially appear at the bottom of the bush, and then spread to the top. After a bloom appears on the spots, this disease can easily infect not only the leaves but also the flowers, and then the fruits. As well as leaves, flowers and fruits in this case simply do not simply fall off. And the name of this disease is cladosporium.
More often than other tomatoes and not only, it affects such a fungal disease as late blight. In this case, the leaves of the plant are covered with black spots. This disease is generally very dangerous. It is quite difficult to cure it, and you need to do it as soon as it appears. And all because this fungus is able to destroy all plants in just a couple of days. Of course, most often it appears in the greenhouse, because there is always high humidity, and dampness is the most favorable environment for this fungus, and if the temperature in the greenhouse is also cool enough, then late blight generally feels great and spreads even faster. Having discovered it at the very initial stage, you can still save your plantings, but if you missed the time and late blight has spread, then you can say goodbye to the harvest.
All leaves infected with late blight should be instantly torn off the bush, but this should be done very carefully so as not to shake the spores of the fungus. And after removing the infected leaves, you can carry out treatment with chemicals that will destroy phytophthora. The main thing is not to forget to initially read the instructions and strictly follow them during processing.
In addition to the fact that with late blight, the spots can be black, they can also be brown.But with the onset of cold, they are simply covered with a bloom of white. If your bushes have acquired these signs, then this is just a type of phytophthora and you need to get rid of it urgently.
If your tomatoes are not covered with sufficiently large black spots, but have acquired a small scattering of black, poorly visible dots, then this is such a disease as black bacterial spot. Initially, these small spots have a bright green color, which is different from the color of the leaves themselves. But they darken very quickly and begin to spread throughout the plant. In addition to the plant itself, the flowers and fruits of the tomato are also affected, and the number of these spots only grows and they turn black. Over time, all these spots turn into a kind of scab. Leaves at this time begin to actively dry and fall off. And also because of this disease, the fruits simply simply cannot ripen. If you do not immediately treat this disease, then you can completely lose the crop. So are the leaves. In the case of this spot, those preparations that contain copper help well in the treatment.
There is also such a disease in which the spots on the leaves and fruits are black and they seem to be pressed inward. This disease appears at a time when the heat is on the street. And it is called alternariosis. The spots can be of completely different sizes, from a few millimeters to several centimeters in diameter, and these spots themselves are very dry. At the initial stage, tomato leaves begin to actively turn yellow, as well as they and tomato fruits are covered with well-visible spots with a black bloom. As soon as you notice such signs on your tomatoes, you need to treat them with fungicides immediately.
But when a large number of brown spots of small size begin to appear on the leaves of a tomato, which in a short time can turn black and gradually increase, this means only one thing, you have such a disease as phomosis. With this disease, not only the leaves are easily affected, but also the fruits, and it does not matter at all whether they had time to ripen. On fruits, these spots initially appear at the base of the peduncle. Over time, one small spot can easily grow up to three centimeters in diameter. This disease appears from a fungus that easily persists in the ground and can constantly infect new plants. And an excellent habitat for it is dampness and a high nitrogen content in the soil. To be sure that this disease is absent on your site, you need to disinfect the soil. And also if you have a greenhouse, you need to carry out not only the cultivation of the land, but also the greenhouse itself from the inside.
How to understand what exactly is missing in tomatoes
With the same success, leaves can have spots with a deficiency or, on the contrary, an excess of any elements. When you know what spots a tomato has with a lack of certain elements, you can easily eliminate this cause, and the leaves will acquire a normal color. By the signs, you can easily find out what trace elements your tomatoes need at the moment and immediately add them, returning your tomatoes to a normal state and healthy appearance.
If the tomato leaves begin to turn yellow at the edges and fall off. At the same time, the plant itself simply withers, and the new young leaves are yellow-green in color, and the veins on the leaf can turn reddish, all this means that the seedlings do not have enough nitrogen. In order to restore health to the plant, you need to water each bush with urea. To do this, you need to take 1 tbsp. a spoonful of fertilizer and diluted in 10 liters of warm water.
If the tomatoes have yellow-brown spots, then they need to urgently fertilize in the form of potassium. With its lack, all young tomato leaves begin to curl up, and the old ones simply turn yellow at the edges, forming a border. In order to add potassium in the right amount, it is best to use potassium nitrate at a concentration of 1 tbsp.a spoonful of saltpeter diluted in 10 liters of warm water. But the leaves of the plant can also turn yellow with too much potassium in the soil. In addition to simple yellowing, spots also appear on the leaves at this time. If too much potassium is very harmful to the root system of the tomato, it may simply get burned. And besides this, with an overabundance of potassium, plants very poorly assimilate other necessary elements. In order to reduce the amount of potassium, you just need to stop applying fertilizers with its content, as well as in no case apply ash.
If tomato leaves begin to turn yellow and at the same time stretch upward, then they lack such an element as magnesium. To do this, you do not need to apply root dressing, it is enough just to carry out external processing of the tomato with magnesium nitrate. In order to prepare the necessary solution, you need to take 1 teaspoon of nitrate and dilute in 10 liters of warm water.
If light green spots appear on the intensely green leaves of the plant, then the tomato lacks sulfur. Light green spots turn yellow over time, and the leaves themselves have reddish veins. Initially, such symptoms appear on young leaves, and only then appear on old, large leaves. And the stem of the seedling itself becomes very tough, and easily breaks under its own weight. In this case, you can save the situation by watering the bush with magnesium sulfate. Place 1 gram of the drug in 1 liter of warm water.
If the leaves appear bluish or purple spots, which means there is little phosphorus in tomatoes. Moreover, this is noticeable not only by the spots, but also because the bush itself completely darkens. Yes, and the leaves with such a deficiency, the leaves of the plant begin to curl inward. The trunk becomes very stiff and fragile, and gradually begins to wither. Gradually, the whole plant may acquire a bluish tint. To remedy this situation, fertilizer with a high phosphorus content must be applied as a top dressing.
How to deal with stains
Only when you understand why certain spots appeared on tomato leaves, you can solve this problem. If the cause is a disease, then it must be treated immediately so that there are no risks of losing the entire future harvest. If spots appeared from a lack or vice versa of a large amount of some element, then this is solved by increasing and decreasing the necessary substances.
Still, the most common cause of spotting is fungus. But the fight against it must be carried out without delay. Remove the leaves, and sometimes the whole plants, burn them, and for the rest, carry out the treatment with the necessary chemical or biological preparations.
In principle, even not experienced gardeners easily understand that something is wrong with the plant, but in order to determine what exactly happened to the seedling, you need to have at least minimal knowledge and understanding, because it is not possible to successfully deal with the consequences without knowing the reasons. Despite the fact that many types of fungus can be overcome with copper-containing preparations, you still need to know how else each type of fungus can be taken separately.
In general, it is always better to prevent the disease than to cure it in the future. After all, you can defeat it only at the initial stage, and then it is no longer the fact that you can cure your plants and generally get a harvest. That is why dear gardeners need prevention. And it is not necessary to use chemistry at the same time, because folk remedies and their effectiveness have not yet been canceled.