How to grow healthy seedlings?
Successful cultivation of healthy seedlings requires proper agricultural practices. If the work was carried out efficiently, in accordance with the requirements of the technology of sowing and care, then growing seedlings is a simple process and planting material is planted in a permanent place absolutely healthy. But it also happens that healthy, friendly seedlings begin to wither and after 1-3 days the seedlings completely die.
The reasons may be non-infectious damage to plants associated with violation of the agrotechnical requirements of the culture to the growing conditions (insufficient lighting, low temperature, high humidity, overfeeding, etc.) and, as a result, the defeat of weakened seedlings by soil infection in the form of fungal and bacterial diseases with a black leg, rot and others. This article is devoted to how to avoid seedling diseases caused by growing errors, how to defeat the black leg and other infections.
Simple rules for growing healthy seedlings
Agrotechnical measures are mainly preventive, but if these simple measures are not followed, then it will be very difficult to grow healthy seedlings.
1. Disinfection of the soil mixture for seedlings
Disinfection of soil and mixtures when growing seedlings in containers, pots, cassettes and other utensils should be carried out as a mandatory agrotechnical measure.
We advise you to read our material: How to prepare the soil for seedlings?
If you did not have time to pre-sanitize the soil mixture, you can disinfect it before sowing the seeds with one of the proposed methods or with your own original one.
- Prepared soil is shed with boiling water, in which potassium permanganate is dissolved (1-2% solution). Within 2-3 days, the spilled soil is mixed, dried. After 3 days, repeat the procedure with a soda solution. Dissolve 100 g of baking soda in 10 l of water. At each dose, the soil is dried and mixed.
- 2 weeks before sowing the seeds, the soil mixture is treated with one of the biological products: planriz, phytosporin, Ekomik yield, Baikal EM-1 according to the recommendations.
- Before sowing, you can treat the soil with Bordeaux liquid (1% solution) or copper sulfate (0.5% solution). The concentration of solutions should be low so as not to burn young roots during seedlings.
After all disinfecting procedures, the soil mixture is dried, filled containers, watered with warm water heated to 24 ° C and sowing in moist soil.
It is noticed. The seedlings grown in peat pots and plastic cassettes are practically not ill with a black leg.
2. Maintaining a neutral soil environment
An acidic environment is favorable for the development of soil fungal infections. Therefore, before sowing seeds for seedlings, it is necessary to check the soil for acidity (litmus paper). The best is considered to be pH = 6.0-6.5. To neutralize the soil using lime, dolomite flour, wood ash.
A neutral environment is very important for seedlings. With increased soil acidity, some of the nutrients become inaccessible to plants. Some gardeners cultivate the soil under the seedlings with dry ash with the addition of sand, maintaining a neutral reaction of the soil and at the same time drying it with excessive moisture.
3. Compliance with the density of standing seedlings and seedlings
In a greenhouse over large areas, sowing should be carried out with the recommended norm, not to overestimate the density of plants. Too thick mass shoots of seedlings can be destroyed by plucking weaker plants: do not pull out and pinch off a weak seedling at the soil level.
Thickened seedlings create their own moist microclimate and provoke the growth of pathogenic mycelium. When thinning seedlings leave a distance between seedlings of 1.5-2 cm, which will provide good ventilation and sufficient illumination of each seedling. When sowing seedlings in separate containers, it is best to sow 2 seeds each, and after germination, remove a weak plant (also by pinching).
4. Compliance with the temperature regime of air and soil
As a rule, crops grown through seedlings are heat-loving. Therefore, strict maintenance of the required level of air and soil temperature is required. Germination of seeds begins at an air temperature in the range +16 .. + 18 ° С, but seedlings appear most actively when the air warms up to +25 .. + 30 ° С, depending on the crop.
Immediately after mass shoots, the air temperature must be reduced to +16 .. + 18 ° C so that the shoots do not stretch out. In this mode, seedlings form the root system faster. In the future, the optimal regime for seedlings of most vegetable crops varies during the day + 20 ... + 25 ° С, and at night +16 .. + 18 ° С.
We advise you to pay attention to our material: Hardening seedlings.
No less important for seedlings is the temperature of the soil. Too cold, as well as overheated, causes inhibition of young plants. The optimum is + 18 ... + 22 ºС. It is especially important to maintain such a temperature regime of the soil during a dive. Lowering the temperature below +16 ºС leads to a deterioration in the supply of nutrients and water to plants, and the survival energy of burnt seedlings decreases.
5. Compliance with watering regime and air humidity
The soil under seedlings should be moderately moist. Watering the seedlings should be warmed up to +20 ° C in the morning, not more often than 1-2 times a week, but better after drying the soil surface. When growing at home, seedlings are watered along the edge of the tank, in the greenhouse - along the furrows.
In the first 6-10 days, watering the seedlings is carried out so that water does not fall on the plants. Frequent and plentiful watering worsens the air regime of the soil, the activity of the root system. In addition, the increased humidity of the soil and air contributes to the rapid development of fungal diseases, and young seedlings can die. Therefore, after watering, very wet soil must be dried with dry sand (this is better), or go to watering through pallets.
You can use small fractions of high peat or dry humus to mulch the watered soil. The optimum air humidity should be maintained at a level of 70-75%. To reduce air humidity, the room is ventilated, but without drafts.
6. Without re-exposure, do not get high-quality seedlings
If home conditions allow, and a small amount of seedlings is required, then the containers are exposed on the window sills well-lit by daylight. But sometimes, regardless of the amount of seedlings grown, it is necessary to supplement it, especially when sowing seeds in January-February.
For seedlings, the recommended daylight hours are at least 12-14 hours per day, but in early spring and winter, up to 50% of the required lighting rate is received by plants. At low light intensities, the plants are chlorotic, stretch and bend toward the light source. Therefore, fixtures are installed in home rooms and greenhouses to provide seedlings with the necessary level and intensity of lighting, but not with heat lamps, but special ones with a cold glow.
Dosing seedlings are usually carried out from 7 a.m. to 20 p.m. Many gardeners use phytolamps or fluorescent daylight. Currently, most greenhouse gardeners are switching to LED lights. They emit red and blue light spectra, which improve the development of seedlings, practically do not emit heat and are very economical in energy consumption.
7. Do not overfeed seedlings
When buying a ready-made soil mixture for home growing seedlings, you do not need to add additional fertilizers, especially nitrogen ones. If the soil mixture is prepared independently, then the plants will have to be fed. Although with a properly prepared soil mixture, you can do without fertilizing, especially crops whose seedlings have a short seedling period (27-35 days).
Normally growing plants with green leaves, a strong stem do not need additional nutrition. Excess nitrogen nutrition is very painful for seedlings. It causes stretching of the plants and their lodging. The stems become thin, light, with elongated internodes, the leaves become a painfully dark green in color. General weakening of plants contributes to a more rapid infection of crops. To avoid overfeeding, seedlings before diving do not need to be fed.
7-15 days after the picking, foliar feeding with kemira, nitroammophos, infusion of ash is carried out with the addition of growth stimulants - epin, zircon and others. If the seedlings are overfilled with nitrogen, it is possible to carry out abundant watering and immediately drain the water from the pan, and mulch the soil with dry sand with a layer of up to 2 cm. You can make small sawdust or flooring, finely chopped straw on the soil surface. Soil microbes will begin to decompose fiber and use excess nitrogen in the soil for this.
To improve nutritional balance during this period, plants can be sprayed with ferovit (iron chelate).
Seedling Disease Control Measures
Agrochemical measures are the fastest and most reliable way to protect seedlings from disease damage. Of the diseases, the most serious diseases are lesions with fungal and bacterial infections. The black leg is especially dangerous on seedlings.
The severity of this disease is very high - to epiphytotic. Within 2-3 days, the roots of plants are affected by overgrown mycelium and seedlings die. Therefore, it is so important to comply with all agrotechnical requirements for growing seedlings.
What contributes to the development of black legs in seedlings?
Despite all the preparations for planting seedlings, some of the typical soil fungal spores, or sclerotia, remain alive and are in resting form. They accumulate in the soil, on plant debris, on seeds, on wooden stands of greenhouses. The accumulated infection under suitable conditions begins to multiply intensively. The mycelium grows in the soil.
At the root level, plant infection begins, which externally manifests itself in the form of wilting and lodging of seedlings. Individual foci of diseased plants merge into a continuous field for the shortest period. If urgent measures are not taken, the seedlings can die completely. In order to fully protect plants, it is necessary to carry out agrotechnical and agrochemical work in parallel.
Distinctive features of the defeat of the black leg
If all the requirements of agricultural technology are met, but the seedlings lie in separate, rapidly growing foci, then the seedlings or young seedlings are already sick. With a black leg disease, the stalk in the basal part darkens, a black transverse constriction is clearly visible. The disease is caused by several types of soil fungi: some affect the seedlings of the first days of growth and development.
Young plants that have become ill during this period darken, become mucilous and rot in the area where the mycelium grows inside the plant (roots, root neck, lower part of the seedling).
Other fungal groups affect an adult seedlings ready for planting. Her disease manifests itself in the form of thinning and darkening (until black) of the root neck, drying of the diseased part. The plant does not die, but the planted in the soil is sick for a long time and forms not quite healthy products (head of cabbage crops are especially affected).
What should I do if seedlings become ill with a black leg?
The first days of seedlings are usually not watered, so as not to provoke a lodging. If it was not possible to prevent the development of the disease, diseased plants are removed and burned. Part of the soil, where the diseased plants were located, is also removed, and the place is treated with infusion of ash.
Typically, such solutions are prepared in advance so as not to waste precious time. Dissolve 2 cups of wood ash in 1-2 liters of boiling water. Insist 6-7 hours. Filter and dilute in 9-10 liters of warm water. This solution is sprayed with plants and soil, about 1 l / sq. m square. At home, before spraying, you need to make trays with seedlings in one place.
5-7 days after 100% seedlings, seedlings are treated with fine spraying with a solution of humate-EM, which significantly increases the immunity of plants and at the same time negatively affects pests. The solution is prepared at the rate of 1 cap per 10 l of warm water. You can use other immune preparations.
Today, experts have proposed a huge list of chemical and biochemical preparations that help protect seedlings from various diseases, including the black leg. With self-growing seedlings, it is safer for family health to use biological products. They effectively destroy soil fungi and fungal diseases on plants and are absolutely harmless to humans and pets.
According to the instructions, biofungicidal preparations allow systematic spraying of plants and soil throughout the period of seedling cultivation, which will completely protect it from diseases not only with the black leg, but also with rot, powdery mildew, late blight, peronosporosis and other diseases. Used for spraying and applying to the soil according to the recommendations - alirin-B, phytosporin-M, trichodermin, gamair-SP, phytolavin-300, bactofit, etc.
An effective way to combat the black leg is loosening and hilling. Loosening of the crust will increase the access of oxygen to the roots, and exclude rotting processes. 2-3 days after the mass emergence, the sprouts are carefully spudded and watered using hollows and grooves. Seedlings should remain dry during this period.
Before picking plants, for the purpose of prevention, the soil mixture is treated with colloidal sulfur at a rate of 5 g per square. m. You can add crystallon or kemiru in very small doses to the soil mixture and mix well. The accessible form and the presence of trace elements in fertilizers will help plants after diving to quickly adapt to new conditions.
Some gardeners, before pickling seedlings, in order to protect them from the black leg, add the drug Barrier, Barrier, Fitosporin to the soil mixture and mix it thoroughly. Plants after such tillage practically do not have a black leg.
The preparations Barrier and Barrier, as copper-containing, inhibit not only fungal, but also viral infections. Therefore, they are recommended to be introduced to protect adult seedlings from the black leg before planting in a permanent place. Before disembarkation, the above-mentioned preparations Barrier, Barrier or in the form of a solution of phytosporin, trichodermin, Planriz are introduced into the wells. If there are no drugs, then before planting seedlings, each well is shed one day before the transplantation with a 1% potassium permanganate solution.
Thus, observing all the requirements of agricultural technology for growing seedlings, you can get a healthy planting material.
Attention! In the comments on this material, we ask you to share your secrets and proven techniques for growing healthy seedlings.