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When growing tomatoes in a greenhouse, the gardener must not only properly care for the plantings, but also regularly carefully inspect them for symptoms of various ailments. Thus, you can observe the curling of the leaves of a tomato in a greenhouse. Such a nuisance may be a symptom of a disease, the result of exposure to pests or violation of the rules of tomato cultivation. Below in the article we will discuss how to determine the specific cause of leaf curling and promptly and quickly eliminate it.
Curled leaves are a universal symptom of improper care.
Answer the question why tomato leaves curl in a greenhouse, even an experienced specialist cannot answer immediately. After all, the reasons for the appearance of this symptom may be different, and to accurately determine it is necessary to visually assess the condition of the tomato, in which direction the foliage curls, and what additional changes are observed on the bush.A detailed description of some of the causes of crowded leaves is given below. In order to establish the exact cause, possible accompanying symptoms of illness and ways to eliminate the problem are also given.
The reason is at the root
Damage to the roots can cause leaves to curl in greenhouse tomatoes. More often this happens during the process of planting tomato seedlings in the soil. When removing seedlings from a container, it is very easy to damage the roots without even noticing it. However, the slightest injury to the root system can lead to tomato leaves remaining curled for several days after planting. After the injury has healed during the rooting process, the tomato leaves will level out and within a few days this anomaly will disappear.
It is worth noting that tomatoes can also suffer damage to the root system as a result of loosening. And although the roots of this crop are located quite deep, it is impossible to loosen the soil deeper than 4-5 cm.
Violation of watering rules
Deeply located tomato roots need increased watering. After all, a small amount of water can only moisten the top layer of soil without nourishing the tomatoes themselves. That is why lack of moisture is one of the most common reasons why tomato leaves curl in a greenhouse.
To eliminate this cause, you need to regularly water the tomatoes with plenty of water. For example, in a polycarbonate greenhouse, fruit-bearing bushes need to be watered once every 2-3 days, spending at least 10 liters of warm water on each plant.This volume of liquid must be poured gradually onto the trunk of the tomatoes so that the water saturates the soil without spreading. Mulching loosened ridges also helps retain moisture in the soil, preventing it from drying out.
It is worth noting that the cause of curled leaves can be not only a lack, but also an excess of water in the soil. If the gardener does not follow the watering regime and regularly “floods” the tomatoes, then the roots of the plants will eventually begin to experience a lack of oxygen and will signal this with the edges of their leaves, bending them upward. Thus, it is very important to monitor soil moisture, since its lack or excess can lead to withering of the plant, rotting of the root system, and the development of fungal diseases.
High temperature in the greenhouse
Tomatoes are heat-loving plants, however, the temperature exceeds +350C can burn them. One sign of excessive heat in a greenhouse is curled leaves. This exact reason can be established using a simple visual analysis: the leaves curl at high temperatures in the greenhouse during the day, and after sunset the greenhouse conditions change, the temperature drops, the tomato leaves stop curling, straightening their plate completely by night.
You can reduce the temperature in the greenhouse and restore the condition of the tomatoes with the help of ventilation. Spraying tomato leaves with urea also helps relieve heat stress in plants. For spraying on a leaf, prepare a solution of 1 tbsp. l. substances into a bucket of water.Treatment with urea, which is also a nitrogen fertilizer, should be carried out exclusively in the evening or in cloudy weather.
Incorrect bush formation
When growing tomatoes in a greenhouse, the gardener strives to form the bushes as compactly as possible, removing excess shoots and lower leaves of the tomatoes. This measure allows you to improve air circulation in a confined space and thereby prevent the development of certain diseases and rotting of tomatoes. Removing excess vegetation also promotes faster ripening of fruits and better filling.
In an effort to get a tomato harvest faster, some gardeners begin to form tomato bushes soon after planting, when the plants have not yet adapted. After removing the vegetative organs, which perform the function of a conditional “pump” of nutrients, the root system cannot properly nourish the tomato bush. As a result of such improper formation of the bushes, the foliage of the tomatoes in the greenhouse becomes bent. You can support the crop at this difficult moment by adding nutrients using foliar feeding on the leaf.
Correct and timely formation of the bush avoids leaf curling. Thus, the first operation to remove leaves and shoots can be carried out no earlier than 3 weeks after planting the plants in the greenhouse. Then the formation is carried out every 2 weeks, removing no more than 3 sheets at a time.
The listed causes of leaf curl are easy to identify and eliminate: the leaves curl, but there are no spots, discolored stains, holes or insects on them. When proper care is restored, the tomatoes quickly “come to life”, straightening their leaves. Short-term curling does not affect crop yield or the health of the plant as a whole. Wherein growing tomatoes in a greenhouse without eliminating the cause, it can lead to the death of the bushes.
You can see an example of curled leaves in a greenhouse and get expert advice on eliminating the cause of the ailment in the video:
The reason is illness
What to do if the tomato leaves curl in the greenhouse, but the plants are cared for in full and according to all the rules? In this case, the cause of the malaise should be sought in diseases and parasitism of pests. The problem can be identified by a number of accompanying symptoms, described below.
Bacterial cancer
This bacterial disease often affects individual tomato bushes in greenhouse conditions. The disease can be identified by the following symptoms:
- tomato leaves curl down, quickly wither, turn brown and dry out;
- cracks, ulcers and bumps appear in the lower part of the stem;
- Yellow round spots appear on ripe and unripe tomatoes. Blackening can be observed in the section of the fruit.
If a diseased bush is discovered in a greenhouse, care must be taken to destroy it.To do this, the bush is cut off at the root, treated with copper oxychloride and left to dry on a trellis. After drying out, the bush and its root are taken out of the greenhouse and destroyed by burning. To prevent the spread of the disease, the tomatoes remaining in the greenhouse are also treated with a solution of copper oxychloride (40 g per 10 liters of water).
Tobacco mosaic
Tomato disease is caused by viruses and can quickly spread from one plant to another in a greenhouse. When tomatoes are infected with tobacco mosaic, the leaves acquire a bumpy surface and curl. In this case, a pattern is formed on the leaf plate with alternating spots and stains of various dark and light green shades.
You can see the symptoms and hear recommendations for treating this disease in the video:
Fusarium
This fungal disease can also be found under the name Fusarium wilt. If the leaves of a tomato in a greenhouse gradually curl into a tube, and the symptom spreads throughout the plant from the lower leaves to the top, then one can suspect the presence of this particular disease. Associated symptoms in this case should be:
- the leaves acquire a light green color;
- damaged, twisted foliage falls off;
- the upper leaves and shoots of the tomato wither;
- A pink coating forms at the bottom of the stem.
In addition to the listed symptoms, at high humidity, infected plants may become covered with a light-colored coating. You can fight the disease with broad-spectrum antifungal drugs. If emergency measures to prevent fungal disease are not taken, all plants in the greenhouse may suffer.The fungus in the soil and on the walls of the building will successfully survive until next year and will also infect plants in the future.
Verticillium wilt
An inexperienced gardener may confuse this disease with fusarium, since the symptoms of these ailments are very similar. With Verticillium wilt, the leaves begin to curl upward. The color of the foliage changes and becomes yellowish. As the disease progresses, the leaves turn more and more yellow, and some of them even fall off, however, this does not prevent the tomato bush from surviving until the end of the season.
It is the listed diseases that most often become a prerequisite for the leaves of tomatoes in a greenhouse to curl and change color and begin to turn yellow. It is imperative to combat viral and fungal diseases, since harmful microflora can survive in the greenhouse for a long period of time, damaging next year’s plants. In order to prevent various diseases, with the onset of the new season, it is necessary to treat the inner surface of the greenhouse with disinfectants.
Curling of leaves due to insect attack
Various insects strive to feast on the juices of tomato leaves. As a result of such parasitism, the leaves begin to wither, turn yellow, curl and dry out. Curling of leaves on tomatoes in a greenhouse can occur as a result of parasitism by aphids, spider mites or whiteflies. You can see these pests in the photo below.
It is worth noting that a spider mite, during its life activity, can tightly wrap a tomato leaf with its web, creating a tube-shaped home for itself. When black aphids suck out nutrients, they inject a special substance that poisons the plant and causes the leaves to curl and turn yellow.
Insects can be controlled using various chemicals or by attracting them into traps. Among folk remedies for pest control, spraying plants with a decoction of chamomile or yarrow shows high effectiveness. Tobacco infusion can also repel harmful insects.
Imbalance of nutrients in the soil
It is no secret that in order to grow tomatoes, it is necessary to regularly maintain a certain soil composition. The word “maintain” in this context is very appropriate, since even the most nutritious soil is depleted in the process of cultivating plants, which forces the farmer to apply fertilizers. During the feeding process, the gardener may incorrectly calculate the dosage of substances, thereby causing some problems to arise. Thus, a deficiency or excess of some microelements can cause tomato leaves to curl:
- signs of an excess amount of nitrogen are curled leaves, excessive thickening of the stems and stepsons of the plant (fatification of tomatoes). At the same time, the gardener observes low flowering activity;
- Tomatoes indicate a lack of potassium by curling the leaves. In this case, you can observe yellowing of the veins and a change in the color of the edges of the foliage, it becomes brown;
- Phosphorus deficiency can be identified by curled leaves and red-purple leaf veins. The tissues of the leaf blade between the veins become grayish-green;
- When there is a lack of copper, tomato leaves at the top of the bush curl inward towards the midrib. In an advanced situation, yellow spots appear on the leaf blades.
You can compensate for the lack of minerals by spraying the leaves of the plant with microelement solutions. In this case, the tomatoes will quickly absorb the necessary substances, and their condition will soon improve. If there is an excess of the mineral, you can use the soil leaching method, in which you need to water the plants with large amounts of water.
Let's sum it up
If, after reading the article, it still does not become clear why the leaves of tomatoes curl in greenhouse conditions, where all the rules for growing the crop are followed and a favorable microclimate prevails, and there are no accompanying symptoms of diseases and insect parasitism on the leaves, then you should think about whether curling may be leaves is a varietal feature of tomato? For example, many indeterminate tomatoes have thin, heavily cut leaves that curl slightly inward. Some varieties of cherry tomatoes also have this feature, so if tomatoes of varieties such as “Fatima” (photo above), “Honey Drop” or “Oxheart” are growing in a greenhouse, then you should not be upset when you see curled leaves, since this sign is the norm for a plant.
