Curling of leaves in tomatoes that grow indoors can be seen quite often. For the most part, such leaves can only be seen on individual tomato bushes, but sometimes almost all tomato plants planted on the site suffer from this. Consider the main reasons why the leaves in the greenhouse begin to curl in a tomato and how to deal with it.
The increased air temperature in the greenhouse and the intense heat that has been established during the cultivation of tomatoes leads to the fact that the moisture from them begins to evaporate intensively, the turgor in the tissues drops, due to which the leaves of the plants begin to curl. To prevent this from happening, certain conditions must be created indoors so that the temperature does not rise above 25-30 ° C during the day for a long time.
If the temperature rises above 30 ° C, and even at low humidity indoors, then in addition to twisting the leaves, the plants may also shed flowers and an already formed ovary. The result of a prolonged heat wave is often predictable and leads to a reduction in tomato yields.
You can quickly reduce the air temperature in the greenhouse if, after each watering, open the doors and all the vents and leave them open for ventilation for a while.
You can also whitewash the glass or film coating on the outside with chalk, lime, or cover it with a light-colored cloth to create protection from the penetration of direct sunlight into the greenhouse. Tomatoes need to be watered more often in the morning and evening to increase the amount of water entering the plants. And in order to reduce the evaporation of moisture from the ground, it must be mulched with plant covering material: straw, hay, or agrofiber put on the beds.
If the leaves on the tomatoes curl strongly, then you can help the plants - feed them by spraying with a solution of urea. Prepare it at the rate of 1.5 tbsp. l. of this nitrogen fertilizer per 10 liters. Consumption rate - 1 liter for each tomato plant.
A sharp drop in temperature
Sharp changes in air temperature in the greenhouse can also lead to the fact that the leaves of tomato seedlings curl. For example, this can be observed after transplanting it to the main growing place, especially if the seedlings have not been well hardened. Adult tomato plants grown in greenhouse conditions can also curl their leaves when exposed to cool air due to a cold snap.
Improper watering: lack or excess of moisture
It is believed that the most common reason for tomato plants to begin to curl and deform leaves is improper watering: both deficiency and excess.
Tomatoes, as a culture, love an abundance of moisture, but it must be applied correctly: they need to be watered not when necessary, and not immediately poured out. a large number of water under each bush, but regularly and in moderate portions. The frequency of watering, as well as the violation of the dosage, cause the leaves to curl in tomatoes.
Particularly affected by a lack of moisture are plants that have just been planted in greenhouse beds (until they take root). At this time, they need to be watered as often as possible, but do not flood them, but water them in small volumes until they grow new roots. After that, subsequent irrigation should be carried out at a frequency of about 1-2 times every week. After mass flowering and during fruit formation, the plants again begin to be watered as often and more abundantly as possible to allow the ripening fruits to pour.
Signs of a lack of moisture that adult plants experience are as follows - in tomatoes, the leaves twist inward, forming, as it were, tubules. This is defensive reaction the tomatoes themselves - this is how they try to minimize the amount of moisture evaporated from the surface of the leaves. This condition of the leaves serves as a signal that it is necessary to immediately start watering the plants. However, it is not necessary to pour out too much water at once, so as not to provoke stress in the plants, it is better to water them a little every day, in small portions, so that the tomatoes are gradually saturated with moisture and can straighten the leaves.
If the leaves of tomatoes in the greenhouse curl up, then this is not a sign of a lack, but, on the contrary, an excess of moisture: in this way they increase evaporation and get rid of excess fluid coming from the roots from the soil. You can help the plants if you immediately stop watering and do not irrigate the tomatoes for about 1-2 weeks.
You can also prevent leaf curl by watering greenhouse plants at the right time for this: not during the day, but in the mornings and evenings, when evaporation from plants is minimal. For irrigation, you need to take water separated from chlorine or well, but always warm (room temperature, but not cold, from which plants receive temperature stress, and their roots will not be able to draw moisture from the soil).
Too much or too little fertilizer
It is known that without regular feeding of good and bountiful harvest there will be no tomato fruits. But they need to be applied correctly, because both an excess and a deficiency of many microelements important for life processes occurring in plants lead to a violation of their content in plant tissues, which causes twisting of tomato leaves.
For example, if the edges of the leaf blades of tomatoes rise up, as with an excess of moisture in the soil, but at the same time Bottom part of tomato bushes turns purple, then this is a sign of an overabundance of the trace element zinc in the soil. If there is a lot of manganese in it, then the tomato leaves first curl, then dry out and wrinkle even more, and acquire a bright green color. With an excess of nitrogen in the soil, the tops of tomatoes usually wither. It is possible to neutralize the effect of excess nitrogen on vegetating tomato plants if potassium fertilizers are added to the soil under them: potassium sulfate (8-10 g) or ordinary ash (50-80 g). This amount of fertilizer is calculated per 1 sq. m. beds.
Calcium deficiency in the soil of beds with tomatoes is manifested by the fact that the leaf blades twist upwards, and top rot appears on the fruits. You can eliminate the lack of an element by adding calcium nitrate to the soil (take about 20 g of fertilizer in a bucket of water, add 0.35-0.4 kg of ash and 10 g of carbamide to it.). Pour 3-4 square meters with this solution. m of tomato plants. If there is a lack of phosphorus in the soil, then the leaves of the tomatoes also curl and become grayish in color. Phosphorus, which is important for plants, can be introduced into the soil in the form of a solution of the well-known superphosphate fertilizer (80-90 g per bucket), which will need to be poured into 3-4 square meters. m beds.
Copper deficiency in the soil is manifested in the twisting of tomato leaves and in their acquisition of a yellow color that is not characteristic of the crop. Small yellow spots may also appear on their leaves, which then begin to blacken. You can feed tomato plants with copper if you treat them with copper-containing preparations, for example, such as copper oxychloride.
Root system damage
It often happens that the leaves of tomato seedlings, just planted in a greenhouse bed, quickly curl into a "ram's horn". This happens because the plants quickly lose moisture due to the root system damaged by negligence when planting. Sluggish plants recover for some time after this, grow roots, and they can be helped in this by watering them often and applying fertilizer as needed. After adaptation and rooting of seedlings, leaf curl in tomatoes is usually much less common.
Tomato diseases
Twisting the leaves of tomato bushes in greenhouse conditions can also be observed in some diseases. Tomatoes can get sick under different circumstances: if they are densely planted, placed in those areas where their kindred nightshade used to grow, and if the agrotechnical rules for growing plants are violated.
Of the diseases characteristic of tomatoes, such a symptom as leaf curling has a stolbur disease. It is the appearance of this disease that can give an answer to the question of why the tops of tomatoes wither, the top leaves of tomatoes are deformed and twisted, and their color has changed to light pink or purple. Another symptom by which stolbur disease can be identified is that the lower leaves of plants, as a rule, acquire yellow. For the treatment of this disease, you can use the drug Fitoplasmin, from which you can observe the maximum possible effect. It is necessary to prepare a working solution of this drug before spraying plants in accordance with the instructions attached to it.
Why do tops wrap around tomato seedlings
Leaf curl can also be observed not only in adult tomato plants, but also in tomato seedlings that have recently been transplanted into greenhouses. The reasons why tops curl in a tomato in a greenhouse are as follows:
- a strong excess or deficiency of moisture;
- cold, not having time to warm up the earth, combined with warm air;
- cold weather;
- heat and sunlight, quickly drying plants;
- dry air in the greenhouse;
- lack or excess of nutrients in the soil (especially nitrogen);
- a small amount of containers in which seedlings are grown (not enough nutrients and oxygen in the soil).
Measures to combat leaf curl on tomato plants in greenhouse conditions are as follows:
- growing seedlings in a container of sufficient volume, if necessary, transplanting it into containers that are more suitable in terms of volume;
- protection of plants with dense covering material from night cooling;
- protection of tomatoes from sunlight by shading;
- humidification of too dry air in greenhouses by spraying the soil with plain water;
- feeding tomatoes with fertilizers prepared strictly in accordance with the recommendations given by the manufacturers of these products;
- timely removal of stepchildren and the formation of a bush according to the scheme recommended for a particular tomato variety or hybrid;
- top dressing of tomatoes with growth stimulants and complex fertilizers for their better development.
All these agrotechnical measures should help the gardener protect tomato seedlings and prevent or reduce the likelihood of twisted and deformed leaves on plants.
Leaf curl in tomatoes common problem when growing crops in greenhouses. In open ground, such a nuisance is less common. .
Causes of leaf curl
The main reasons are
- The greenhouse is too hot.
- Tomatoes lack moisture.
- Lack of batteries.
- Excess fertilizer.
- Root damage during planting seedlings or subsequent care of tomatoes.
- Untimely removal of stepchildren. The leaves curl, too, when too many stepsons are removed at the same time.
- Pests are sometimes also the cause of tomato leaf curl.
- Features of the variety.
Depending on the cause, the leaves curl either up in a boat or down in the form of a chicken foot.
Reason 1. Temperature
In the greenhouse, the temperature is always at least 5-7 ° C higher than outside, even if the doors and vents are open. Therefore, at a temperature in the greenhouse above 27-28 ° and low air circulation, in order to avoid excessive evaporation of moisture, the leaves are twisted into a tube. At night, when the heat subsides, they straighten up again.
Very often the leaves curl due to high temperature.
What to do
To prevent leaf curling in hot weather, greenhouses are left open overnight. To reduce the temperature, the greenhouse is shaded. There must be constant air circulation inside it. Even in cold weather, it must be ventilated.
reason 2. Lack of moisture
With insufficient watering, especially in the heat (and in greenhouses, these factors are inextricably linked), tomatoes also reduce the evaporation area due to twisting of the leaves.
- It is recommended to water tomatoes in greenhouses at a temperature of 16-20°C every 7-10 days.
- At a temperature of 20-25°C once every 5 days
- At a temperature of 25-30 ° C every other day
- Over 30 ° C - daily, but very moderately.
This only applies to greenhouse plants, for open ground such an irrigation regime will not work, because there the tomatoes are additionally watered with precipitation. When choosing an irrigation regime, you should always take into account the growing conditions in your area.
If the leaves of the tomatoes are curled, then the first thing to do is to ventilate the greenhouse and water the crop.
Immediately abundantly water the plants should not be. It is better to water for several days in small volumes. It is especially necessary to observe this regimen during the fruiting period.
reason 3. Lack of batteries
If neither watering nor airing helped, and the leaves remained twisted, then the problem is more serious than expected: plants. The leaves curl differently, depending on which element is in short supply.
Phosphorus deficiency
The leaves curl up and turn purple on the underside. Phosphorus is a macronutrient; tomatoes consume it in large quantities.
To compensate for the deficiency of phosphorus, the culture is watered with an extract of superphosphate. To prepare it, pour 1 glass of fertilizer with 1 liter of boiling water (otherwise it will not dissolve) and leave for 12-18 hours, stirring regularly. The finished extract is diluted with water up to 10 liters and the tomatoes are poured under the root. The application rate is 0.5 liters per bush.
You can add dry ash or superphosphate, but then you will have to wait 7-10 days longer for the effect.
Tomatoes need to be fed with phosphorus.
Copper deficiency
The lack of an element is much less common (especially when treating tomatoes with copper-containing drugs for diseases), but its deficiency is not as rare as one might think. With a lack of copper, the edges of the leaves twist up. Yellow vague spots appear on the leaves, which blacken in acute deficiency.
There are many spots and they are randomly distributed over the entire leaf surface. The leaf looks healthy but is yellow and curled. To eliminate the problem, tomatoes are sprayed with any preparations containing copper. The same solution can be watered bushes.
Both spraying and watering not only make up for the deficiency of the trace element, but also protect tomatoes well from many diseases.
Requires micronutrient supplementation.
Potassium deficiency
The leaves are rolled up with a tube, a brown border forms along the edges. Tomatoes consume potassium slightly less than phosphorus, so it is advisable to make it with each top dressing. With a pronounced deficiency, the bushes are fed with any chlorine-free potassium fertilizer.
The best for tomatoes is potassium nitrate, which also contains a small amount of nitrogen. 1 st. l. fertilizers are diluted in 10 liters of water. Irrigation rate 0.5 liters per bush.
An excellent fertilizer will be an ash retract: 100 g of ash is poured with boiling water and insisted for a day, stirring regularly. Then the solution is filtered and watered tomatoes under the root. The consumption rate is 0.5 liters per bush. If ash infusion is sprayed, then 40 g is added to the working solution laundry soap as an adhesive.
Such bushes require potash top dressing.
Lack of nitrogen
It usually happens on poor soils and with gross violations in the agricultural cultivation technique. With a lack of nitrogen, the leaves become yellowish and shrink. As nitrogen starvation increases, the leaves begin to curl down, turn yellow and dry.
Urgent top dressing is necessary with any nitrogen mineral fertilizer. If it is not there, then the tomatoes are fed with manure, or an infusion of grass. 0.5 l of infusion is diluted in 10 l of water and the plants are fed. The application rate is 1 liter per bush.
Pale leaves in tomatoes due to lack of nitrogen.
lack of calcium
Leaves curl up. A little earlier, top rot appears on the fruits. Feed tomatoes with calcium nitrate: 10 g / 10 l of water.
This is where calcium supplementation is required.
reason 4. Excess fertilizer
Some summer residents, in an effort to get the maximum yield, apply so much fertilizer (especially organic matter) to tomatoes that the plants begin to suffer from their excess, and this, in turn, very quickly leads to diseases.
excess nitrogen
The leaves at the top of the bush are twisted, the rest are very powerful, of a normal appearance. To neutralize excess nitrogen, stop all organic top dressing. Under the bushes, an extract from wood ash or any potash fertilizer containing no chlorine.
Excess nitrogen can also be harmful.
Excess zinc
It does not occur so often, but most summer residents cannot recognize it and only aggravate the situation. This happens when the multiplicity and frequency of applying microfertilizers is violated. The leaves curl up and hang like during a drought.
The main sign of excess zinc is the appearance of a purple hue on the lower part of the stem (no higher than 20-30 cm). To correct the situation, tomatoes are fed with organic matter, and microelements are not added for at least 15-20 days.
Some varieties have a genetically determined purple hue. But then the stem is evenly painted in this color.
Excess zinc is difficult to recognize.
reason 5. Damage to the root system
After planting seedlings, especially in a greenhouse, tomato leaves may curl slightly. This is fine. The root system of seedlings is usually less developed than above-ground part, so a few days after planting, the leaves of the plants are twisted. If after 5-7 days they have not acquired a normal appearance, it is necessary to water the tomatoes with Kornevin or Heteroauxin stimulants.
When planting seedlings in the ground, try not to damage the roots of plants.
Often the roots are damaged during deep loosening of tomatoes. The leaves curl up evenly throughout the bush. Neighboring plants look healthy. To remedy the situation, tomatoes are watered with root formation stimulants (Kornerost, Kornevin) and substances that support plant immunity: Epin-extra, Zircon.
reason 6. Incorrect pinching
Untimely removal of stepchildren leads to twisting of the leaves. Stepchildren are removed when their size is no more than 5-7 cm. If they have already outgrown, then this is too painful for the plant, so you either have to leave them or remove them gradually over several days.
Removing overgrown stepchildren can affect the leaves of tomatoes.
If the large stepchildren were removed and the tomatoes reacted to this by twisting the leaves, then the only thing that can be done is to spray the tomatoes with Zircon or Epin-extra.
reason 7. Pests of tomatoes
The greenhouse whitefly often affects tomatoes in greenhouses. This is a small butterfly that lays its eggs on the underside of leaves. The larvae and adults (butterflies) feed on the juices of the plant. Insects secrete a sweet pad, on which a sooty fungus settles. The insect reproduces very quickly. It settles first on the youngest and most tender leaves on the tops of plants.
Avoid a large accumulation of pests on tomato bushes.
Signs of defeat.
- The leaves are deformed and curled, and then turn yellow and fall off.
- On the underside, insect secretions can be found in the form of sticky honeydew and small white scales - the remains of cocoons.
- Backlog of bushes in development.
- The appearance of black spots of soot fungus on the stems and leaves.
What to do
When the whitefly spreads, it is very difficult to deal with it. The pest reproduces extremely quickly, and most insecticides do not work on older eggs and larvae. Therefore, emergency measures must be taken at the first detection of a pest.
When shaking whitefly-infested bushes, the butterflies take off and are easy to spot.
- To catch butterflies, glue traps are used, which are placed on the tops of the bushes.
- With a small spread of the pest, Fitoverm is used. Spraying is carried out on the underside of the leaves. and tomatoes can be removed 2 days after treatment. Spraying is carried out repeatedly with an interval of 3-5 days to destroy newly appeared individuals, since the drug does not work on eggs. With strict observance of the intervals of treatments, you can significantly reduce the number of pests.
- Simultaneously with Fitoverm, tomatoes are sprayed with Fitosporin or Alirin-B for the prevention and destruction of black fungi.
- In case of mass infection of tomatoes with a pest, all fruits are removed in the phase of technical ripeness, and the bushes are treated with Aktara. Treatments are carried out on the underside of the leaves at least 3-4 times with an interval of 4-7 days. After spraying, tomatoes should not be eaten for 20 days.
reason 8. Features of the variety
In some, leaf curl is a genetic trait. Cherry and small-fruited tomato varieties are mainly prone to this.
There are also some tomatoes.
Usually in this case, the leaf blade curls down, forming a "chicken foot". But in some varieties, the leaves can curl up. In this case, nothing needs to be done, neither feeding, nor watering, nor airing will help here. It's just a feature of the variety.
Conclusion
If the leaves on the tomatoes are massively twisted throughout the greenhouse, then this is either a violation temperature regime or lack of moisture.
If the leaves curl only on individual bushes, then most likely this is a lack of nutrients. In this case, they twist gradually, first on one plant, then on the second, third, etc.
First of all, these bushes are carefully examined, and then on one of them they are fertilized with the necessary fertilizers. If the measures taken have given a result, then the rest of the plants are also fed. If there is no result, then continue to select the right fertilizer before receiving a positive response. Only after receiving a positive reaction to top dressing, all other tomatoes are fed with the same fertilizer.
With your help, I managed to cope with the acidity of the soil. The tomatoes are doing well. Blossom, powerful, leaves are dark green. But in the middle row, opposite the doors, the tops of the tall tomatoes, as it were, “curled up”, twisted into a “cam”. I read literature. Explanations are different. Basically, I fill it with too much water. This is not, because I rake the soil, it's dry. There may be insufficient watering. The middle row is practically blown through and the earth dries faster than the side beds. Plants are tall, powerful, bloom. I think they need good watering. Not 2 times a week, as they say in various reference books. With this heat in polycarbonate greenhouse the earth dries very quickly. Maybe I'm wrong. Tell me what to do. Previously, when growing tomatoes in makeshift greenhouses, there were no such problems. Sincerely, Valentina.
Hello Valentine! Many summer residents face this problem. Curly tomato leaves can different reasons. You indicated one of them correctly - insufficient watering during the heat period. A plant that lacks moisture will curl its leaves. Thus, the tomato manages to reduce the evaporation of moisture by reducing the surface area of the leaf plate. At the same time, the lower leaves, illuminated less by the rays of the sun and better ventilated, remain normal.
Important! Choose a watering mode based on appearance plants. But remember that excess moisture provokes the occurrence of fungal diseases.
Too much nitrogen in the soil
If there is an excess amount of nitrogen fertilizers in the soil, the plant begins to fatten. At the same time, the plants have powerful stems, dark green leaves and curly tops. The plant directs all its strength to the growth of green mass. big harvest Unfortunately, there will be no fruit if no action is taken.
It is necessary to balance the amount of fertilizer in the soil by fertilizing with potassium, which is contained in wood ash. Dilute a glass of ash in a bucket of water and spill the tomatoes. Spraying the leaves with a solution prepared from one teaspoon of potassium sulfate and a liter of water also helps.
Aphid tricks
Small black aphids can also cause twisting of the leaves, which first settles in the axils of the leaves, and then moves to the stem and petioles of the leaves. Aphids, when sucking juices, introduce a specific substance into the tissues of the plant, which deforms the stem and twists the leaves. Insects hidden in the folds of leaves are difficult to kill with insecticides.
Important! When spraying, try to moisten all the sinuses and folds of the leaves.
A diseased plant under attack by aphids looks just like you describe.
curl virus
This is perhaps the most unpleasant reason because viral diseases of tomatoes are not treated. Plants are infected by insects and cutting tool. Sick tomatoes are best removed immediately so as not to infect other plants. Stepchildren break out manually, without using a pruner.
Often the owners of home gardens notice a problem when growing tomatoes: the upper leaves of the plants are twisted. Twisted tops prevent full photosynthesis, and the plant begins to wither from nutrient deficiency. Why is this happening?
A possible reason that the leaves of tomato seedlings began to curl is damage to the roots during planting. Over time root system will recover, and the tomatoes will take root. This is the most harmless option for twisting tomato tops.
Such necessary procedures, like pinching and pinching, can also cause twisting of tomato leaves if they are not carried out correctly. The first pinching is carried out 20 days after planting seedlings in the ground, then - 1 time per week. In this case, you can remove no more than 2 lower leaves in 1 procedure, otherwise the plant will weaken. You can pinch only shoots that have reached 10 cm in length. Excessive pinching is stress for the tomato bush, which can lead to twisting of the leaf tops and falling of the ovaries.
There are more serious options for why tomato leaves began to twist.
Humidity and high temperature
Excessive or, conversely, insufficient moisture can affect the curling of the leaves. When the plant rolls its leaves upwards, in a "boat", it means that it does not have enough moisture. So tomatoes compensate for its deficiency: they reduce the area from which the liquid evaporates, “save”. Abundant, but rare watering will help to avoid drought (once a week is enough, in the heat - 2 times). Excess water adversely affects the roots, leads to their decay. In this case, the plant ceases to receive enough nutrients and oxygen, as a result - twisted tops. Tomatoes - whimsical vegetable crop. The soil should always be loose so that excess moisture does not accumulate at the roots of tomatoes. Therefore, mulching compulsory procedure, which will help not only to cope with excess water, but will also prevent the rapid evaporation of moisture from the soil.
Tomatoes do not like extreme heat. If the temperature in the greenhouse or on the street exceeds + 34 ... + 35 ° С, the leaves of the tomatoes are twisted into a tube. In the evening or at night, when the temperature is noticeably lower, the tops that have twisted straighten out and return to their previous state. A thick layer of mulch will help save tomatoes from high temperatures, hiding bushes from direct impact sunlight opaque material. If a we are talking about the greenhouse, then in addition to these measures it must be often ventilated.
Lack and excess of trace elements in the soil
Insufficient micronutrient content in the soil will lead to twisting and discoloration of the leaves in tomatoes. Basically, the plant may be deficient in potassium, phosphorus and zinc. Insufficient potassium content in the soil leads to the top of the leaves curling up, changing their color to brown, and ripe tomatoes appear light spots. Phosphorus deficiency can be identified by curled down leaves and purple veins. Zinc deficiency is manifested by the curling of large tomato leaves, and their reverse side acquires a purple hue. To compensate for the lack of trace elements, top dressing with ash or mineral fertilizers(superphosphate, potassium nitrate).
Excess fertilizing with nitrogen fertilizers can also lead to twisting: the leaves roll into a ring. The stem becomes thick, new, powerful shoots are formed. The tomato will delight with lush green leaves, but to good harvest it won't. Nitrogen blocks the access of roots to such important trace elements as phosphorus, potassium and zinc. Need to stop nitrogen fertilization and replenish the missing trace elements.
Diseases of tomatoes (video)
Insect infestation and infectious diseases
Can cause leaves to curl up and be damaged by pests: black aphids, spider mite and whitefly. Insects colonize the underside of the leaves, sucking the juices out of them. This leads to the fact that the affected part of the plant curls, turns yellow, then dries up and falls off. First, the pests hide in the leaf axils, where it is difficult to immediately detect insects, and then they infect not only all the leaves, but also the stems of the tomato, which can lead to the death of the entire bush. Careful treatment of tomato bushes (each leaf, each stem) with insecticidal preparations will help get rid of insects.
Another threat to growing tomatoes is damage by microorganisms, bacteria and fungi. In a plant affected by bacteriosis, all leaves and stems are twisted down, the tops and flowers become smaller, become pale and fall off. The carriers of infectious diseases may be some pests, or the seeds were initially affected by microorganisms. Sick bushes must be carefully destroyed. The infection also affects the soil, so all neighboring plants and beds from under infected tomatoes must be disinfected with Pharma-iodine or another antimicrobial agent. In the future, it is advisable to plant cruciferous green manure, radish or mustard in this place in order to completely rid the soil of infection.
By finding out in a timely manner why tomato leaves curl and quickly eliminating the cause, you can achieve success in such a difficult agronomic business as growing tomatoes.
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