Causes of yellowing tomato leaves

Any changes in the condition of the plants may be a sign of some kind of disease. What causes tomato leaves turn yellow and how to deal with it? We consider in detail the causes and treatments.

Causes of yellowing tomato leaves

Natural processes

Slight greening is a normal change inherent in tomatoes. Often this happens after transplanting seedlings to a permanent place. The procedure is stressful for the seedlings, therefore, to maintain the nutrition of the apex, the culture has to drop the leaves.

If the lower leaves turn yellow in a tomato, then you should carefully look at the bushes. Natural processes are almost painless for plants, there is no noticeable mass clarification and dropping of greenery. Culture itself copes by dropping leaves.

Temperature changes

If the leaves turn yellow on ground tomatoes, then this may be a sign that the vegetables are frozen. Tomatoes are very sensitive to the warmth of the earth, therefore, when cold, they immediately change the color of the foliage.

Heat is another culprit of the yellowness of the plates. Unhardened, weak seedlings are especially affected in the first weeks after landing on a permanent place of development. At first, the green wilts from the heat, then the irreversible processes of dying off begin.

What to do when tomato leaves turn yellow? If the cause of the problem is temperature changes, we advise you to protect the seedlings. During the period of frost, the landing is covered with a film at night. In the summer heat, we recommend shading the bushes with an old cloth.

Humidity

Tomatoes are a very moisture-demanding crop. The main root of the plant reaches a length of 1.5 meters, however, the main part of the system is located in the lower layers of the soil. With a lack of watering, greens lose turgor, brighten and curl.

Excess irrigation leads to the fact that the earth does not have time to dry out and decay begins. This is true in cool periods with a lack of sunny days. It is especially necessary to carefully monitor the degree of humidity in greenhouses and greenhouses. An increase in the safe level causes the lower leaves of the tomatoes to turn yellow.

What needs to be done to prevent agricultural technology errors? We recommend that you revise the irrigation schedule and draw up a rough plan. Before each procedure, check with a stick how dry the soil is. In addition, you must regularly loosen the planting and remove weeds. "Sad" bushes are sprayed with a solution of "Epina" or "Zircon".

Illumination

If yellowing appeared on the tomatoes, then the plants may not have enough sun. Most often, such bushes have weak foliage on the opposite side and an elongated stem. From the lack of ultraviolet light, balcony varieties, seedlings suffer.

To remedy the situation, you need to provide the vegetables with the right lighting. After the seeds have hatched, it is better to illuminate the seedlings with a phytolamp. If the culture has yellow leaves, then it is worth rearranging it on a more suitable window sill. We recommend choosing house hybrids resistant to light deficit.

Root problems

Root health affects plant growth

Roots are the most vulnerable spot in all plants. Parasitic insects devour the roots of both young and old crops. A broken system cannot properly deliver nutrients to the tops, which causes yellowing.

Overgrown seedlings also have no normally formed roots. Due to the fact that the plant had to develop for a long time in a limited space, the roots do not adapt well. In a new place, seedlings have to adapt to new conditions and remove excess greens.

By the way, after inaccurate transplantation of bushes on a bed, rough loosening of the soil or pulling out weeds, roots can also be damaged. After picking, young plants get sick, which manifests itself in the form of a color change. If you find that the leaves of the tomatoes turn yellow due to the underground parts, then you need to wait until the system is fully restored. We recommend watering the problematic plantings with “Kornevin” or spraying with “Epina” solution.

Top dressing

Tomatoes are a very voracious culture that prefers to develop and pamper with fruits on "greasy" soils, with regular fertilizers. A deficiency or excess of any of the microelements causes a change in the color of the tops. In the neglected state, the ovaries fall, and the crop matures poorly.

Nitrogen

Why do the leaves of a tomato turn yellow on the site? With a deficiency of this substance, the plant will be plain and pale. If you notice that the plates began to lighten and become covered with reddish veins, then this may be starvation. Lack of nitrogen is dangerous during periods of growing green mass and fruit setting. Such a crop grows small, hard and poorly stored, and seedlings die off the seed.

With an excess of an important nutrient, tomatoes “fatten”, increasing the tops to the detriment of products. Ripening slows down, and yellow and brown necrosis appear on the green, which then die off. The leaves are twisted, and the stem branches heavily.

How to fix the problems of agricultural technology? In case of nitrogen deficiency, we recommend immediately watering with urea (one spoon per bucket of water). Excess micronutrient is “cured” only by strong washing of the soil with thorough drying.

Potassium

The substance is necessary so that the processes of development of stems and fruits are properly regulated, and cells begin to be updated correctly. With a shortage, the ripening of the crop worsens, and the leaves turn yellow unevenly from the edge, then turning into a brown border. Yellowness gradually spreads from the tips to the center, after which the plate is wrapped.

What to do to prevent potassium deficiency? Plants must be treated with potassium sulfate before the start of the fruiting period. Suitable as watering under the root, and spraying on the leaf. The procedure is carried out carefully, trying to get the spray on the plates above and below.

Magnesium and Zinc

Both trace elements are responsible for photosynthesis of crops and the formation of chlorophyll. If you do not fertilize vegetables, then small yellow spots appear on the plates, leading to the death of greenery. Even in tomatoes, foliage curls inward and “rusty” edges are observed. The fruits of such bushes are small and ripen early.

When making fertilizing, we advise you to pay attention to the composition of the drug. A comprehensive tool always contains all the necessary elements. Procedures are carried out every two weeks, alternating between root and extra-root events.

Boron, Sulfur and Calcium

Plants can be saved

With a lack of substances, the upper parts of the bushes are most often affected. The leaves turn yellow, the tops die off. Farmers notice that the "hungry" plants began to grow, dump all the flowers and ovaries. Tops necrosis occurs in the most neglected state.

What to do if you notice signs of deficiency? Calcium and boron are not as important as nitrogen, potassium or phosphorus, but shortages often occur on impoverished soils. It is better to replenish the substances by introducing complex preparations marked "For Tomatoes". Recommended procedures are performed every two weeks, especially during the flowering period.

Diseases

Yellowing leaves in your tomatoes can activate some kind of disease. Mistakes after transplantation often cause unpleasant ailments that cause disc color to change. Knowing the signs of ailment, you can quickly begin treatment.

Curly hair

The extermination of insect parasites and varietal herbs is not a cosmetic procedure, but an important process for vegetables. The disease is transmitted to tomatoes through whitefly bites and from affected neighboring plants. Outbreaks are noted both in untidy areas and in adjacent vegetable gardens.

The yellow curly virus is a very dangerous ailment that affects all parts of the culture. The diseased bush does not tie fruit, which negatively affects the future harvest. The illness is recognized by characteristic signs:

  • leaves turned yellow;
  • deformation of greenery, especially the upper parts;
  • wrinkled surface;
  • noticeable veins;
  • shedding flowers.

What is the best way to get rid of the disease after the leaf has turned yellow? Affected plants are not treatable, so you have to remove plantings. It’s easier to prevent an ailment than to deal with the consequences of inattention.

In order to prevent, it is necessary to process seedlings from whiteflies. Regular spraying with mineral oil reduces the risk of spreading the disease. In addition, we recommend purchasing seeds of hybrids that are immune to ailments.

Fusarium

If the tomato leaves turn yellow, then this may be a sign of a dangerous fungal disease. In addition to discoloration, a whitish bloom of mycelium appears on the underside. The turgor of the plates decreases and the upper parts are deformed, especially the growth point. The greenery twists, dies, after which the affected bush dies.

Many beginning farmers do not know why fusarium occurs. Most often, the fungus is activated with crowded plantings and excessive use of mineral fertilizers. Another cause of illness can be insufficient lighting and increased humidity. The disease spreads very quickly, especially at a temperature of 27 C.

"Among the sources of the spread of the disease can be not only infected seeds, but also the remains of plants from compost or tools that constantly cultivate the soil."

If you notice that the lower leaves of a tomato turn yellow, then you should carefully examine each bush. The greater the defeat, the less likely to save the seedlings. A diseased tomato is a source of infection, so it is uprooted and burned behind the site. For minor infections, we recommend spraying the plants with a Falcon solution (1 mg per 3.5 L).

For prevention purposes, experienced farmers do not forget to carefully destroy weeds and disinfect the soil before planting seedlings. In addition, the seed material is selected with immunity to Fusarium infection and is treated with fungicides before sowing. If plants often suffer from the effects of the "yellow" fungus on the plot, we recommend moving the crop to another part of the garden.

Tomato is a very tenacious type of vegetables, however, ignorance of its requirements often leads to agricultural errors and can ruin the entire crop. If you pay attention to a change in color and structure, then you can predict the problem in the early stages. Thanks to our review, it is now easy to understand why tomato leaves turn yellow.

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