Why pepper leaves turn yellow: what to feed and how to treat

Why do peppers turn yellow?

Changes in the color of plant leaves can occur gradually, or over one or two days. When you see yellowing or pale foliage, you need to quickly find out the cause of the problem.

Irrigation violations

Plants turn yellow, wither, shed leaves and ovaries when there is a lack or excess of moisture. Peppers are watered moderately, monitoring soil moisture levels. Drought is detrimental to the crop, but it does not tolerate stagnation of water near the root system.

Watering with cold water also causes problems. Plant roots stop absorbing water and nutrients, and even if the soil is moist, the bushes change color.

Lack of nutrition

Pepper is demanding when it comes to nutrition, and if it senses a lack of some components, it quickly reacts by yellowing, drying out, and wilting of the leaf blades. This manifests itself both at the stage of growing seedlings and in adult plants.

Most often, yellowing is a sign of nitrogen starvation, although non-infectious chlorosis can be caused by a lack of potassium, as well as trace elements - zinc, iron, boron.

Lack of lighting

The culture requires a lot of light, otherwise the plants develop slowly and grow poorly. The stems of such peppers are weak, light green, and the leaves match them. The bushes stretch out and bend.

Temperature changes

This vegetable loves comfortable warm conditions, does not tolerate cold (below +12ºC), as well as extreme heat (above +32ºC). A sharp change in temperature indicators leads to a slowdown in growth. There is a general yellowing of the leaves and falling off.

Root damage

The problem arises when picking seedlings, planting seedlings in a permanent place in greenhouses, hotbeds or beds. Often the roots of plants are damaged during deep loosening and removal of weeds. Weak or deformed roots are the cause of slow growth of seedlings and reduced yield of a variety or hybrid.

Pests and diseases

A common cause of yellowing and wilting of leaf blades is infections and pests. In addition to changing the color of the leaves, twisting, bending of the leaf plates, and drying out occur.

In diseased bushes, leaves, flowers, ovaries and even formed fruits fall off.

Yellowing of seedlings: causes, how to treat

In most regions of Russia, heat-loving crops are grown at home through seedlings. And it is at this stage that the problem of yellowing leaves often appears. There are various reasons:

• poor quality seeds. The shoots are weak, frail, with pale leaves. Seedlings are stunted and get sick;
• incorrectly selected soil mixture for peppers;
• lack of lighting. Peppers sown in January and February especially often suffer from lack of light. At this time, the daylight hours are short, which affects the condition of the plants;

• cold window sills on which there are boxes or cups with seedlings;
• unsuccessful picking of peppers;
• overwatering of seedlings;
• watering seedlings with cold water;
• lack of moisture;
• temperature changes;
• dry air;
• pests (spider mites, aphids). They often switch to peppers from seedlings of other crops or from indoor plants;
• infections.

Having identified the cause, they immediately take action, otherwise the seedlings will die. What to do:

1. When there is a lack of nitrogen, the plant gives a signal by yellowing the lower leaves. Seedlings are fed with urea or complex fertilizer. A good result is obtained by planting Azogran (one granule) under each seedling.

2. If the cotyledons turn yellow and the pepper already has 2-3 true leaves, there is no reason to worry. The cotyledons have done their job, they are no longer needed. But if there are no real leaves, and a couple of cotyledons have turned yellow, the watering regime is reconsidered. This is usually associated with watering with cold water. Therefore, the soil is slightly dried, and from now on the seedlings are irrigated only with warm, settled water.

On a note! It is possible to feed such seedlings with ready-made fertilizer, for example, Kemira, Aquadon Micro or Agricola 3.

3. If the soil becomes too moist, stop watering for several days. Gently loosen the soil and drain excess water (pallets, drainage). If there is a suspicion that the roots have rotted, spill the soil in the boxes with a solution of Fitosporin.

4. For seedlings sown early, additional lighting is provided. There should be at least 12 hours of daylight. Use phytolamps, LED or fluorescent lamps.
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5. Containers with seedlings on window sills are placed on stands (wooden grates, foam sheets). In severe cold weather, it is better to remove the peppers from the windows for a while, but do not forget about high-quality lighting.
6. On hot days, seedlings are shaded from direct sunlight. Place cardboard and foil and cover the glass with thick cloth.

7. Having discovered pests on the bushes, the seedlings are sprayed with Fitoverm and Vermitek.
8. Bell pepper seedlings often suffer from a fungal infection - blackleg. At the first symptoms - yellowing of the leaves, thinning of the lower part of the stem, it is necessary to add calcined river sand to the seedlings and water the soil with a pink solution of potassium permanganate.
9. To avoid problems after picking, it is advisable to immediately sow the peppers in separate pots. If common seed boxes are used, replanting is done no later than the first couple of true leaves appear.
10. Before planting in a permanent place, the seedlings must be hardened off, gradually accustoming them to new conditions. To increase immunity, bushes are sprayed with Zircon and Epin.

White, gray, black and brown spots on the leaves of pepper seedlings

Any spots on the leaves indicate a plant disease.

Causes

• bacterial diseases
• fungal diseases
• viral diseases

Treatment

White spots with a brown border (pictured) are characteristic of the disease septoria. This is a fungal disease and needs to be combated with antifungal drugs.

The same is the case with powdery mildew of pepper - when whitish focal spots or white coating appear on the leaves, both on the outside and on the inside. Immediate treatment with fungicides is necessary.

Brown and black spots can be signs of bacterial spotting, dry spotting, and many other bacterial lesions. In this case, it is necessary to treat the seedlings with Phytoflavin.

Wet, brown and putrefactive spots appear when the disease is late blight; it is also fungal and the plants must be treated with drugs against the fungus.

In case of any disease, if part of the seedlings are still healthy, there is a good chance of saving it. Plants that have not yet been damaged are treated with antifungal drugs and antibiotics, the soil and planting container are completely replaced and pre-disinfected. After transplantation, the seedlings are treated with immune stimulants such as Epin.

Why do the leaves of greenhouse peppers turn yellow?

When grown in shelters, yellowing of plants is most often caused by lack of nutrition, bright sun, or too dry air. Peppers are planted in small greenhouses (film, polycarbonate), hotbeds, and tunnels. During hot weather, the air temperature in shelters rises significantly, which has a bad effect on plants.

There is a high risk of plants getting burns, especially if sprinkling or spraying on the leaves was carried out. In greenhouses, leaves turn yellow from burns, because on hot days, film, glass, drops of water on peppers play the role of a magnifying glass.

It's not just peppers that feel comfortable in greenhouses. In such conditions, various pests feel at ease - aphids, spider mites, whiteflies. Having settled on plants, insects feed on the sap of leaves and shoots, which causes the plant to turn yellow, wither and stop growing.

Prevention measures

The following preventive measures are suitable for peppers to help protect the leaves from yellowing:

• Before planting, seeds and soil are disinfected;
• Only healthy seedlings are planted in the greenhouse;
• when purchasing seeds, choose types of peppers that are resistant to viruses and pests;
• peppers are regularly sprayed with mixtures made from germ-resistant plants.

It is also important to disinfect the greenhouse premises and tools used to care for plants.

Yellowing of peppers in open ground

The reasons for yellowing of plants in garden beds are similar to those that lead to problems in greenhouse peppers. But there is also its own specificity:

• water scarcity. It is observed in hot weather, with irregular watering and lack of precipitation. Peppers instantly react by changing color, withering of leaf blades, and loss of color and ovaries;

• cold snap. The Russian climate is unpredictable, and even at the height of summer cold snaps are possible. When the temperature drops to +12ºC, the roots stop working and the plants stop growing;
• deficiency of individual nutritional components. Most often, there is not enough calcium on the ridges, which leads to the appearance of yellow spots on the peppers and leaf deformation;
• excess light. With excessive amounts of sun, the decomposition processes of chlorophyll are accelerated significantly, which leads to pale foliage;

• pest attacks. Along with spider mites, peppers in beds are attacked by wireworms, cutworm larvae, thrips, and the Colorado potato beetle;

• diseases. On ridges there is a high risk of plants being damaged by various types of rot, fusarium, and stolbur.

Failure to comply with growing conditions

The conditions in which peppers germinate and are kept after the appearance of cotyledons are different. Before the first shoots, the containers are removed to a warm place. Temperature (23-25) is more important than light. Peppers will hatch even in complete darkness.

But, as soon as the sprout loops have appeared, and even more so the cotyledons have unfolded, the crops are moved to saturated but diffused light (12-14 hours). And you need cooler air: 22 degrees is the limit, 19-21 is optimal. This point is more difficult to accomplish than providing the necessary lighting. The catch is that at home, peppers grow on windowsills:

• heating radiators from below - hot air rises to the seedlings;
• from the window - coolness;
• ventilation - drafts and sudden changes from hot air to cold air from the street.

The slightest disturbance in the temperature balance, and the pepper seedlings turned yellow in a couple of days.

How to help plants

Both in shelters and in open-air ridges, when changes in leaf color are detected and plant growth slows down, peppers require urgent help. They identify the cause and get to work.

Nutrition problems:

• the lower leaves turn yellow and fall off due to lack of nitrogen. With nitrogen starvation, the tips of the leaves turn yellow. Apply nitrogen fertilizers, observing the doses of fertilizers;
• deficiency of iron (yellowness in the center of leaf blades), calcium (irregular shape of leaves, spots), manganese (spots) is eliminated by adding complex compositions with microelements Agrovit, Agricola, Factorial;

• Lack of potassium (leaves turn yellow and curl down) appears more often in cold summers. Add ash, potassium sulfate, and muddy soil;
• To eliminate phosphorus deficiency, peppers are fed with superphosphate.

The first feeding after planting is done approximately 14-16 days later. Spraying on the leaves is indicated, for which potassium nitrate, nitroammophoska or concentrates of ready-made fertilizers are used.

On a note! When applying fertilizers and foliar treatments of plants, strictly follow the instructions.

If there is an excess of moisture, watering is temporarily stopped. The soil is mulched with hay, straw, rotted peat, humus, and ash is added. It is necessary to adjust the watering schedule, taking into account the age of the plants, conditions (beds, shelters), and weather.

For irrigation, use heated water +22ºC, avoiding moisture getting on the flowers, ovaries and leaves of peppers when watering. It is convenient to water in grooves, holes or use drip irrigation systems.

On hot days, greenhouses and greenhouses are opened, providing comfortable conditions for peppers. In this case, it is advisable to avoid drafts and overcooling of plants at night. The optimal air humidity in the greenhouse is 70-75%.

If it gets sharply cold outside, add solutions of Florist, Uniflor-bud, and Novosil. Feeding sweet peppers with Aurum-S gives good results. For greenhouse peppers, it is important to avoid sudden changes in day and night temperatures, so the shelters are ventilated during the day and always closed at night.

To control pests, insecticides and folk remedies are used:

• treatments with Arrivo, Bicol, Fitoverm, Inta-Vir help against aphids and whiteflies.

• You can get rid of thrips using Actellik and Akarin;
• Fitoverm, Iskrabio, Keltan, Bitoxibacillin will get rid of spider mites.

Among the folk recipes used to exterminate insects are infusions of celandine, yarrow, tobacco dust, decoctions of wormwood, and tansy. Spider mites cannot tolerate treatments with infusions of dandelion, garlic, and hot pepper. Before spraying, add shavings of laundry soap to the solutions (for adhesion).

If yellowing is associated with disease, spraying the plants with fungicides is recommended. Herbal infusions give results only in the initial stages, but if the degree of infection is serious, the plants are dug up and destroyed.

Treatment:

• for late blight, treatment with Strobi and ash infusion is indicated;

• whey solution helps against powdery mildew;
• gray and white rot are destroyed with Bordeaux mixture and other copper-containing preparations;
• Viral infections cannot be completely cured. But an iodine-milk solution or treatment with Afidol solution will help to weaken the impact of the pathogen in case of mosaic and stolbur.

What to do

Treatment methods vary depending on the cause of yellow discoloration. If the problem is caused by a deficiency of micro- or macroelements, it is necessary to fertilize.

The main recommendations of gardeners are presented in the table:

2-3 days after fertilizing, the drying of the bush slows down. After a week, the process of regeneration and color restoration begins. Pepper slowly absorbs fertilizers, so it makes no sense to expect an immediate effect.

When yellowness is caused by other reasons, use the following recommendations from experienced gardeners:

1. If the problem of yellowing of the shoots is caused by the cold, you need to additionally insulate the pepper with film at night. An alternative is to apply manure liberally. It is important to constantly monitor the temperature in the greenhouse.
2. You need to water the bushes with warm water 3 times a week.
3. To reduce the risk of mosaic infestation, use only quality seeds and regularly disinfect equipment and shoes.
4. If yellowing is caused by stress, it is best to use artificial analogues of natural biostimulants, which enhance the natural protection of plants from aggressive environmental factors. For example, the drug "Epin" is suitable.

When trying to help the plant, it is important not to overdo it. Unsystematic application of fertilizers, additives and constant spraying with drugs has the opposite effect.