Overview of complex mineral fertilizers and plant growth regulators

Nitrophoska contains three main nutrients: nitrogen, phosphorus, and potassium. It is produced in granules and is highly soluble in water. Nitrophoska is used on all types of soil:

• on heavy soils, it is applied in the fall for deep ploughing;
• on light sandy and sandy-loam soils, it is applied in the spring with shallower incorporation.

Nitroammophos contains nitrogen and phosphorus. It is used on all soils and should be supplemented with any potassium fertilizer.

Nitroammophoska differs from nitrophoska by a higher nitrogen content, phosphorus, and potassium.

Ammophos is a phosphorus-nitrogen fertilizer containing twice as much phosphorus as nitrogen. It is best applied during sowing and planting.

Potassium nitrate consists of nitrogen and potassium. The application of nitrate as top dressing during fruit set in cucumbers and tomatoes is highly effective.

"Ideal" is a natural humic fertilizer. It contains the essential nutrients required for the healthy growth of agricultural crops. Applying this fertilizer as top dressing increases plant resistance to various diseases, improves growth, and increases yield. "Ideal" solution can be used for soaking seed, bulbs, and tubers.

"Ispolin" is a natural humic fertilizer produced in granules. One type of fertilizer is intended for vegetables and root crops, while another is specifically for potatoes. "Ispolin" contains all essential nutrients and growth stimulants. It has a longer storage life compared to "Ideal." It enhances flavor qualities and extends the shelf life of vegetable crops.

Recently, growth stimulants have been gaining popularity, although it would be more accurate to call them growth regulators. It is not just that they promote higher yields; they also enhance the consumer and taste qualities of fruits and vegetables.

Growth stimulants are successfully used in gardening and vegetable growing for:

• accelerating rooting during propagation;
• reducing pre-harvest fruit drop;
• slowing the germination of tubers, root crops, and bulbs during storage;
• weed control, etc.

Like all biologically active substances, growth regulators require very careful handling. With an overdose of these compounds, you may not only fail to get the expected effect but face the exact opposite result.

Most biologically active substances at low and very low concentrations act as growth stimulants, help boost immunity, and activate fruiting. At high concentrations, these same preparations have effects that suppress natural processes in the plant. Therefore, when using stimulants, it is better to provide a little less than too much.

For top dressing plants, it is good to use humic fertilizers, heteroauxin, "Kornevin", succinic acid, "Epin", "Biostim", "Silk", "Immunocytophyte", "Zircon", "Cytovit", and "Gibberellin". Aloe juice can be used as a stimulant. However, in this case, one must consider the biological compatibility of the plants.

Specifics of using aloe juice:

• Most favorable for tomato seeds tomato.
• Soaking seeds of eggplant, cabbage, and lettuce is permissible.
• It should strictly not be used for treating seeds of pepper, onions, celery, and cucurbits.

For soaking seeds, use undiluted aloe juice. To prepare it, use leaves that are three years old or older with an intense green color. From a mature plant, break off the lower leaves and place them in the refrigerator for a week, after which the juice is squeezed out. Do not use leaves that have lightened or yellowed or have dry tips.

Soaking in aloe juice does not replace disinfection; it should be carried out after heat treatment of the seeds. Tomato seeds are kept in aloe juice for 24 hours and then sown or placed for germination without washing off the juice.

Humic fertilizers ("Tellura" and "Flora") are obtained from natural raw materials: peat and lignite. These fertilizers contain nitrogen, phosphorus, and potassium, but in such small quantities that they cannot be considered a source of these elements.

Humic substances introduced with this type of fertilizer primarily change the physical properties of soils:

• water-holding capacity of light soils increases;
• water permeability of heavy soils increases;
• soil structure is improved;
• soil density is reduced.

There is an increase in the microbiological activity of the soil, both in the first year of fertilizer application and subsequently. Along with the increase in the number of microorganisms, the enzymatic activity of the soil also increases, which, in turn, increases the mobility of soil nutrients. Thus, the use of humic fertilizers significantly changes the conditions of soil plant nutrition, causing an active strengthening of nutrient mobilization processes in a form assimilable by plants.

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Heteroauxin (from the auxin group) stimulates root formation. To stimulate this process, the root system of plants is soaked for 8–24 hours in an aqueous solution of heteroauxin before planting. After planting, it is beneficial to irrigate the plant with this solution.

To increase the effectiveness of heteroauxin when rooting cuttings, the following application rates are used:

Growth, Rooting, and Fruiting Regulators

• Yield increase from "Zircon" — 35–60%
• Vegetable yield growth from "Silk" — 25–30%
• Ripening acceleration with "Zircon" — by 1–2 weeks
• Heteroauxin concentration for seed — 500 mg/l
• Succinic acid solution for tomatoes — 0.01%

Heteroauxin helps the agronomist stimulate fruit set and obtain seedless fruits in greenhouses. For seed treatment of tomatoes and cucumbers, a working concentration of 500 mg/l of the preparation is used. The effect of heteroauxin can be enhanced by joint application with vitamins and nicotinic acid. In such tank mixtures, carrot, beet, and onion seed are kept for 10–12 hours. It is permissible to use one of the following variants of working solutions:

• 600 mg/l heteroauxin + 100 mg/l vitamin B1;
• 600 mg/l heteroauxin + 100 mg/l nicotinic acid;
• 600 mg/l heteroauxin + 100 mg/l vitamin B1 + 100 mg/l nicotinic acid.

Succinic acid accelerates plant flowering and stimulates fruit set. Spraying tomatoes with a 0.01% aqueous solution during the budding phase increases yield and protects plantings from late blight. To obtain the maximum effect, plants during the growing season are treated according to the following schedule:

"Kornevin" works as a direct analogue of heteroauxin, but in a form more convenient for planting operations. Before planting transplants into the soil, their root system is simply dusted with the dry powder of the preparation, which ensures quick establishment. For comprehensive plant support, "Biostim" is suitable — a natural regulator based on auxins and gibberellins. It activates the immune system, helps survive stresses, and stimulates the growth of vegetative mass when sprayed.

"Biostim" is recommended for use in the following technological operations:

• presowing seed treatment to accelerate germination;
• pricking out and planting transplants;
• improving the rooting of nursery plants.

Immunoprotectors and Anti-Stress Preparations

"Epin" and "Epin-Extra" preparations help protect greenhouse crops from sharp temperature fluctuations, frosts, flooding, drought, and soil salinization. The active hormones maintain plant immunity during stresses and neutralize the negative consequences of pesticide applications. Treated seed germinate faster, and the transplants grown from them acquire resistance to damping-off, late blight, rhizoctonia, and powdery mildew.

To prepare the working solution, follow the sequence of actions below:

1. Warm the closed vial with the preparation at room temperature until the precipitate is completely dissolved, then shake vigorously.
2. Prepare the working solution: for seed of most vegetables, take 3–6 drops per 50 ml of warm boiled water; for tubers and bulbs, use 1 ampoule per 2 l of water.
3. Keep the seed, tubers, or bulbs in the solution for 18–24 hours.
4. Dry the treated material before sowing or place it in meltwater for germination.

The natural fungicide and stimulant "Silk" increases the yield of vegetable crops by 25–30% and enhances their vitality during frosts and drought. The preparation is used on tomatoes, cucumbers, cabbage, onions, and potatoes. It significantly reduces the risks of planting infection by late blight, downy mildew, brown rust, root rots, wilt, and black bacterial spot.

The auxin-based preparation "Immunocytophyte" provides plant protection against diseases for a period of up to one to two months. It is used for presowing treatment of seed and tubers, as well as for spraying during the growing season. The preparation is intended for treating potatoes, tomatoes, cucumbers, cabbage, onions, grapes, fruit, berry, and floral crops. It increases resistance to late blight, alternaria, rhizoctonia, various types of scab, damping-off, powdery mildew, and bacterioses.

The natural regulator "Zircon" stimulates root formation, accelerates plant development by 5–10 days, and brings harvest maturity dates closer by 1–2 weeks. Its application increases seed germination, accelerates the establishment of cuttings and transplants, while reducing the accumulation of heavy metals in tissues. The yield increase when using "Zircon" is 35–60%. In addition, the preparation effectively protects plantings from late blight of potatoes and tomatoes, downy mildew of cucumbers, scab of potatoes and apple trees, gray mold of strawberries, powdery mildew of black currants, as well as bacteriosis and fusarium of vegetable and floral crops.

The temperature of the working solution during pepper seed treatment should be 23—25 °С.

Citovit (microfertilizer) — contains a full complex of trace elements in organic form, which is the most accessible for plants. It increases the yield of fruit, berry, and vegetable crops, and improves the decorative qualities of floral crops.

Seed soaking and top dressing with "Citovit" accelerate seed germination and plant growth, increase plant resistance to unfavorable growing conditions and wintering, reduce fruit set drop, and prevent the death of growing points and diseases of the fertilized crops, such as chlorosis, various leaf spots, "rosette" disease in fruit trees, rots, etc.

The greatest positive effect is achieved through combined treatment of seeds, transplants, and vegetation-stage plants with "Epin-extra" and "Citovit", and for root crops — with "Zircon" and "Citovit". С ак бе 59.5 595.5395]_|

"Gibberellin" (at present, about 60 different gibberellins have been discovered) — exerts an influence on the functioning of the chromosomal apparatus. It is capable of significantly affecting stem length, as well as stimulating both cell division and cell elongation.

At the same time, "Gibberellin" does not affect root growth, and in high concentrations in water culture, it even worsens the condition of the roots. "Gibberellin" activates seed germination, fruit growth, and delays tomato ripening.

It is known that dormant buds and seeds of a number of species are brought out of dormancy by the action of low temperatures. In these cases, the temperature factor can be replaced by treatment with "Gibberellin". For the germination of light-sensitive seeds, the action of light is necessary. This can also be replaced by the action of "Gibberellin".

"Gibberellin" is used to increase the yield of seedless (sultana) grape cultivars, which are characterized by relatively small berries. Spraying grape vines with a "Gibberellin" solution (30 mg per 10 m²) during flowering or 5—7 days after flowering ends contributes to a 1.5—2.5-fold increase in berry size and a 50—100% increase in yield. Furthermore, grape ripening is accelerated by several days.

However, to be fair, it must be said that raisins made from treated grapes are inferior in taste and some other qualities. "Gibberellin" also has a positive effect on some seeded grape cultivars: the number of berries increases, the seed content decreases or vanishes, and the cluster loosens (which reduces the susceptibility of berries to phytopathogens), and ripening is accelerated. For the purpose of increasing yields, "Gibberellin" is also used for treating strawberry plantations.

Top dressing can be soil-applied or foliar. Soil-applied top dressing is useful to add during the initial growth period of vegetable transplants and during flowering. Foliar top dressing is mainly applied in the late stages of plant development.

Top dressing should be performed after irrigation, preferably in the evening, after first weeding out all weeds. When applying, organic substances are diluted with water:

• mullein and horse manure — 1:5;
• wood ash — 1 cup per bucket of water.

A bucket of liquid top dressing made from organic or mineral fertilizers is sufficient for 20 holes of transplanted crops or for 10—20 linear meters of crops sown by seeds.

For foliar top dressing, plants are sprayed with weak solutions (1—2%) of mineral fertilizers or microfertilizers, or they are dusted. It is best to carry out this work in the evening or early in the morning.

Among the latest generation fertilizers, compositions that combine organic and mineral fertilizers are of interest. Such preparations not only effectively "feed the plants" but also increase their immunity and contribute to better transplant establishment. In addition, these fertilizers can be used to treat seeds, tubers, and bulbs, which significantly increases sprout emergence and their marketability.

Such preparations include "Humisol" — a complex humic fertilizer, which contains an extract from vermicompost. The advantage of "Humisol" lies in the fact that it is based on the waste products of living worms, which contain highly valuable biologically active components.

What fertilizers a plant needs at a given stage of development can be suggested by their appearance:

• in case of nitrogen deficiency, the plant's stem development slows down, and the leaves have a pale green color.

When determining the condition of plantings, it is important to take into account visual signals:

• in case of phosphorus deficiency, leaves acquire a red tint. Tomato is particularly sensitive to phosphorus deficiency. Red-violet spots appear on the underside of the plant's leaves;
• in case of potassium deficiency, the edges of the leaves turn brown, and the tops of the stems curl. Yellow spots appear on the fruits;
• in case of magnesium deficiency, leaves acquire a pale green color and gradually turn yellow. In cucumbers, the edges of the leaves turn brown;
• in case of calcium deficiency, the terminal buds of plants die off, and roots stop growing. Dark spots appear on young leaves;
• in case of boron deficiency, terminal buds die off, and flowers and fruit set drop. In cauliflower, the heads turn brown; in beets, the heart rots;
• in case of copper deficiency, the tips of the leaves turn white.

Specifics of vegetable crop nutrition in greenhouse cultivation

The efficiency of fertilizers for cabbage directly depends on the soil type, its nutrient content, and the irrigation regime. The crop produces maximum results when organic and mineral mixtures are applied together. Phosphorus is vital for cauliflower, broccoli, and late-maturing white cabbage, while potassium is essential for mid-late and late-maturing head cabbage cultivars.

Top dressing of white cabbage is carried out only 1–2 times per growing season. The first application is timed to the rosette phase, the second — to the beginning of mass head formation.

Root crops are highly sensitive to nutrition levels but have strict limitations regarding organic matter. Fresh manure or peat delays the ripening of root crops and impairs their appearance and taste. Organic components should be applied strictly to the preceding crop, while humus, peat composts, or mineral fertilizers are incorporated directly for beet and carrot.

Cucumbers are extremely demanding of soil fertility and the amount of organic matter. The soil for this crop is generously enriched with manure, which creates optimal conditions for development and improves the flavor of the cucumbers. Top dressing during the growing season should begin from the moment fruits are formed.

• Nutrient consumption during fruiting — 70–80%
• Timing of the first top dressing — 10–15 days after emergence

Tomatoes prefer cultivated light and medium soils and respond excellently to phosphorus. Moderation is important when working with nitrogen, as its excess stimulates the growth of foliage and suckers to the detriment of fruit ripening. The phosphorus-potassium group, on the contrary, accelerates tomato ripening and reduces nitrate content.

Bulbous crops are sensitive to the fertility of the substrate and the salt concentration in the soil solution. Onion sets grow better on cultivated sandy loams. Excessive nitrogen nutrition delays bulb ripening; therefore, nitrogen is dosed strictly according to the technology.

Leeks require loam soils rich in organic matter. They respond actively to manure and nitrogen fertilizers, while their need for phosphorus and potassium is considered average. It is advisable to apply part of the nitrogen in the form of urea along with irrigation water.

Garlic is planted on light loams with a high humus content. The crop does not tolerate a high concentration of the soil solution, so organic matter is applied exclusively to preceding crops. Leafy green crops (lettuce, spinach, dill) are also grown on light soils; organic matter is applied to them in advance, and nitrogen is provided with irrigation during the early growth period.

Legumes (peas, broad beans, beans) are the least demanding in terms of fertility levels. They are capable of independently fixing atmospheric nitrogen and assimilating sparingly soluble soil phosphates.