What to do if the leaves of tomatoes in a greenhouse curl?
Often the leaves of tomatoes planted in a polycarbonate greenhouse begin to curl. They curl up like a tube, twist up or down. By the different positions of tomato leaves, you can understand what mistakes the vegetable grower has made in care.
Main causes of twisting
Depending on the cause of the change in leaf shape, a treatment strategy is chosen. The source of infection can be determined by examining the nature of damage to leaves, tomato stems, and soil around the plants.
Incorrect pinching or pinching of tomatoes
Leaves may curl up or down. This occurs due to stress in the plant if too many stepsons or large shoots have been removed.
Important! If pinning is done incorrectly, the yield will decrease.
Overdose of organic fertilizers
After excessive feeding with fresh manure, the following may occur:
- root damage due to ammonia burn;
- an excess of nitrogen - the stem becomes thick, the leaves become dense, the bush itself becomes dark green, the upper leaves of the plant curl down into a ring;
- phosphorus deficiency - the edges of the leaves turn up, then bend down, become dark with purple veins, the bush grows slowly, the stem becomes brittle.
Violation of watering rules: underwatering and overwatering
If the edges of the leaf blades curl down, this is a signal of a lack of moisture. At the same time, the leaves become soft and limp.
If fragile leaves curl upward in an attempt to increase evaporation, this indicates an excess of moisture.
Root damage
If the plant is transplanted incorrectly into open ground, mechanical damage to the roots occurs. The leaves curl along their entire length and fall down.
When the roots are damaged by underground pests (mole crickets, wireworm larvae, root-knot nematodes), the tomato leaves curl into a ring and fall down.
How to recognize root system pests:
- mole cricket - holes and tunnels up to 2.5 cm are visible in the ground;
- the wireworm larva eats holes in the roots and crawls inside the stem;
- root-knot nematode - swellings and nodules form on the roots.
Tomato infections
Warm greenhouse conditions are characterized by:
- Bacterial cancer. Appears when the humidity in the greenhouse is more than 80% every day, the tomatoes do not have enough light, there is too much moisture, and the constant temperature is above +25 °C.
How to find out? The plant turns yellow, the edges of the leaf blades curl on one side, the other retains its original shape. In the middle tier of the plant, ulcers and necrotic spots appear, the leaves dry out but do not fall off, the stem cracks, yellow mucus flows from the cracks, its core turns yellow, and the fruits become covered with white spots. - Tobacco mosaic is a virus that affects tomatoes when there is little light, poor ventilation of the greenhouse, dense planting, excessive watering and air humidity above 80%.
The leaves of the plant are completely curled, covered with yellow spots, swollen, and the fruits stop growing. - Verticillium wilt - a fungal disease that occurs after excessive watering of dry soil and when the temperature decreases to 20 ° C and below.Young tops of tomatoes curl inward at the edges, turn yellow and dry out, the stem becomes light brown when cut, necrosis develops and the roots die.
Pests
Pests infect tomato leaves, feed on their juice, and most often settle on the reverse side:
- Potato aphid - a small insect of red or green color. Drinks juice from young leaves at the top, causing their edges to bend upward. Tomatoes have sticky spots from honeydew secreted by aphids.
- Whitefly - a white midge that flies away from a bush when a person approaches it. The juice of tomatoes is drunk by whitefly larvae, which look like gray specks of dust that stick around the entire bush. The leaves become limp, pale yellow spots are visible around the bites, and under them there are dark and light sticky spots. What to do with tomatoes when the leaves are curled up in a boat? Fight whitefly.
- Spider mite. Its presence explains why the leaves of tomatoes curl inward in a greenhouse. In this case, the lower leaves of the plant suffer. Over time, the mites form a whole web, and the surface of the leaf becomes covered with white or colorless areas.
Eliminating the causes and preventing curling
When curled leaves are detected on tomatoes, the first step is to adjust the growing conditions of the crop. Tomatoes are demanding in terms of watering and fertilizing; every mistake in care can critically affect the yield.
| Cause of twisting | How to fix | How to prevent |
| Incorrect stepsoning or pinching | Plants feed nitrogen, phosphorus or potassium foliar fertilizers. | Stepchildren are removed on time and according to the scheme prescribed for a specific plant variety.It is optimal to pick off 2-3 leaves per week, and break off the stepsons until they reach 5 cm.
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| Overdose of organic fertilizers | Excess nitrogen can be eliminated by adding potassium sulfate (8-10 g per 1 m²) or ash (50-80 g per 1 m²) to the soil. To flush nitrogen from the soil, tomatoes are watered generously. Stepchildren that have reached 12-18 cm are removed. If there is a lack of phosphorus, feed with superphosphate according to the scheme specified in the instructions. |
Fresh manure, even many times diluted with water, is dangerous for the plant when feeding roots. Tomatoes are fertilized with special preparations suitable for the variety, soil, climate, and growing conditions.
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| Breaking the rules glaze: underfilling and overfilling | If the plants lack moisture, you need to start watering - every day in small portions. If overflow occurs, stop irrigation for 1-2 weeks. |
Tomatoes love moisture. Young plants that have just been planted in the ground are watered in small volumes 2 times a day until they are completely rooted. After this, water 1-2 times a week. When the bushes have bloomed and fruits have begun to set, watering is increased as for young plants. The rest of the time, they don’t pour under a bush. Spray warm, settled water, preferably well water, dropwise in moderate portions |
| Mechanical damage to roots | The bushes are fed with phosphorus fertilizer by spraying to stimulate the root system | Carefully transplant the plant into the ground. Method: Fill a tomato in a pot with water, carefully remove it and transplant it into the prepared hole.
Rooted tomatoes are loosened without touching the roots. |
If there are no violations of agricultural practices, and damage on the leaves indicates the presence of a disease or pests, therapeutic and preventive measures are carried out.
| Name of disease or pest | How to fix |
| Bacterial cancer | There is no treatment. The bushes are dug up and burned. Uninfected tomatoes are treated with copper preparations: Bordeaux mixture, copper chloroxide or copper sulfate. The best time for processing is from 10 to 12 or from 16 to 18 hours. |
| Tobacco mosaic | It also cannot be treated. You can help the tomato by removing the affected leaves to healthy tissue. To prevent the disease from affecting healthy bushes, they are treated with whey (a solution for dilution with water 1:1). Spraying is carried out every week, even after the fruits ripen. |
| Verticillium wilt | The infected plant is dug up along with the roots and burned. The soil where the affected tomato grew is replaced. To prevent other plants from getting sick, spray them with an aqueous soap-ash mixture twice with a 10-day break.
To prevent the leaves of the plant from curling due to verticillium wilt, foliar feeding is carried out - 2 g of zinc sulfate, 3 g of boric acid, 5 g of magnesium nitrate per bucket of water. Spray with this mixture 3 times every 15-20 days. |
| Potato aphid | Leaves affected by aphids are removed, and the plant is doused with water to wash away other insects. For minor lesions, wipe the leaves with soapy water or spray with bioinsecticides: Akarin, Bitoxibacillin.
For large lesions, they are treated with chemicals: Trichlorometaphos, Aktara, Biotlin. Traditional recipes are used. Tobacco infusion: 400 g of dry tobacco leaves are cut, pour 1 bucket of boiling water, leave for 5 days. Herbal decoction (one to choose from): yarrow, wormwood, marigold, chamomile, celandine, dandelion. Pour 1 liter of boiling water over 500 g of chopped green parts of the plant and boil for 20 minutes. Leave for 2 days and spray on the affected leaves. |
| Whitefly | For small lesions, it is better to fight it with biological agents: Verticillin, Boverin. You can introduce macroflora, encarsia or amblyseius, that is, predatory insects, into the greenhouse. Fumigation of plants with tobacco sticks is suitable: 3 times every 10 days. For extensive lesions, spray with insecticides: “Aktellik”, “Tanrek”, “Inta-Vir” |
| Spider mite | Leaves affected by mites are removed. Wipe or spray the tomatoes with soapy water or horseradish infusion. The bucket is filled 1/3 with chopped shoots and leaves of horseradish, filled to the brim with water, after an hour, filtered and sprayed on the tomatoes. Repeat after 12 days.
Special biological products that kill ticks: Fitoverm, Kraft. Chemicals: Oberon, Borneo. "Apollo" |
| Medvedka | The mole cricket eats up the roots of the plant, so it will not be possible to revive them. They fight the pest with granular baits: “Medvetox” or “Thunder” |
| Wireworm | Remove the wireworm by pouring a slightly pink solution of potassium permanganate under the bush. Chemical preparations include Diazolin 10-RG, Provotox or Bazudin granules. |
| Root nematode | Damaged plants die. They are dug up and destroyed. Bushes are not treated against this pest. After harvesting, the soil in the greenhouse is changed. |
Results
There are many reasons why the leaves of tomatoes in a greenhouse may curl. In searching for the source, you will have to analyze each bush, carefully examine the damaged leaves, and look into the root system.Having identified the problem, all that remains is to act according to the recommendations for treating tomatoes so as not to lose the harvest.