Why do pepper seedlings have leaves that curl up and down like boats?

Peppers are heat-loving plants that thrive in moist, loose, nutritious soil, light, and warmth. Growing peppers from seedlings requires following proper agricultural practices. One of the characteristics of pepper seedlings during the growing season is the curling of the upper leaves during the period of active growth.

Vegetable growers who have encountered this pathology are interested in how dangerous this is and how it will affect fruiting.

What causes twisting?

Pepper seedling leaves can curl for several reasons. Dropping temperatures, rising acidity, and increased humidity due to lack of drainage can cause young plants to develop various diseases, which can affect the leaves.

Most often this phenomenon occurs due to:

• uneven leaf growth, which is often observed in this crop;
• lack of microelements in the soil;
• aphids and spider mites;
• fusarium, in which the lower leaves begin to curl in the initial stage.

To determine the cause of the disease, a careful examination of the plants is required. It is necessary to evaluate:

• temperature changes during the day;
• air humidity level;
• dryness of the soil;
• the presence of insects or cobwebs on plants;
• soil sterility;
• soil saturation with nutrients.

Any factor from this list can cause leaf curling on pepper seedlings.

When twisting is a natural process of vegetation

Young leaves curling upwards will be observed in pepper seedlings when the soil is rich in nutrients but lacks warmth and sunlight. This causes the plants to stretch, and biochemical processes in the delicate leaves slow down.

With an excess of nitrogen, the midrib of the leaf quickly increases in length, while the cells of the leaf blade, due to a lack of light, are unable to divide quickly. This causes severe tension in the leaf blade, causing curling. After some time, the cells of the leaf blade become active, begin to divide normally, and form a full-fledged leaf that straightens and acquires its characteristic density and shine.

To solve this problem, thin out dense plantings. This will increase sunlight exposure. If nighttime temperatures drop significantly, insulate the seedlings in the evening by covering them with a heat-retaining material. If seedlings were started early, placed near a window with wooden frames that let in cold air, you can cover the window with a layer of plastic to create a greenhouse effect.

When to worry

The presence of insects or webs on the stem should be a warning sign. Pests that infest seedlings pierce plant cells with their proboscises and suck the sap, causing wilting and curling of the leaves.

You should test the leaves for stickiness. Aphids, which are brought in by ants, secrete a sweet sap. They feed on the pepper's sap and destroy the growing stems, gradually destroying the entire plant. If you find webs inside the curled leaves, the pot has been infested with spider mites, which are just as damaging as aphids.

If the plant's surface is clean, the root system may be compromised. Lack of drainage and cold watering can damage the underground part of the plant, which affects the seedlings' appearance.

Leaf curl can be caused by fungal diseases, which develop for various reasons. Fusarium wilt develops on pepper seedlings if the seeds were infected with fungal spores. This infection thrives in soil where tomatoes, cucumbers, beans, or corn were previously grown.

This fungal disease is dangerous for seedlings because it threatens to destroy the entire pepper crop that develops on plants infected with fusarium early in the growing season. Mycelium spreads through the vessels to various parts of the stem, starting from the lower layers of leaves. This characteristic makes the fungal disease easily distinguishable from natural leaf curl, which is observed only on the tops of the peppers.

What measures should be taken if seedlings are damaged?

Depending on the symptoms detected, methods for protecting the seedlings from death are selected. If the curling was caused by insects, the seedlings should be treated with Intavir, diluting an ampoule or tablet in water according to the instructions. This will be sufficient to rid the pots of pests. Most of the peppers will recover, and the seedlings will continue to grow. The harvest will not be harmed.

Detecting fusarium wilt on seedlings will require strict quarantine measures. The seedlings will have to be destroyed, the pots washed, and treated with a fungicide.

1. To avoid losing seeds and seedlings, fungal diseases should be prevented: Purchase soil from a store.
2. When using your own nutritional mixture, fry all ingredients at a temperature above 60C until smoky.
3. Pour the prepared soil with a dark solution of potassium permanganate or Fitosporin.
4. Home-grown seeds must be pre-treated with a fungicide.
5. If the leaves are curling due to a lack of nutrients, the peppers should be treated with a micronutrient fertilizer and then dusted with wood ash. This will solve the potassium deficiency in the soil.

When leaf curling in pepper seedlings is caused by dry soil, which often occurs in small pots placed close to heating devices, in addition to generous watering, mist the leaves with a spray bottle several times a day. This increases humidity, reduces moisture stress, and improves the plants' appearance.

Reviews

In their reviews, experienced gardeners share techniques for preventing leaf curling.

Tatyana, Moscow region: "I grow pepper seedlings on a windowsill with a central heating radiator underneath. The soil dries out quickly, causing the pepper leaves to curl. To solve this problem, in addition to watering with warm water, I regularly mist the plants with clean water. After that, the leaves straighten out and begin to shine."

Ivan, North Caucasus: "I sometimes see pepper seedling leaves curling due to sudden temperature changes. I use homemade soil made from black soil, stove ash, vermiculite, and peat to grow peppers. I add potassium nitrate at a rate of 1 tablespoon per 5 liters of soil to improve nutrition."

Valery, Crimea: "I sometimes see leaf curling in densely planted plants. Then I thin out the seedlings, leaving 2-3 cm between the shoots. This is enough to ensure the plants receive the necessary light. If the leaves do curl, I check the temperature and cover the seedlings at night to retain heat."