Mechanism of action and application regulations for the preparation Narcissus in crop production

Narcissus preparation: immune shield and application regulations

The "Narcissus" preparation activates the natural defense mechanisms of plants, helping them resist fungal diseases and pests at the cellular level. This is not just a protective barrier, but a stimulant of internal immunity. The active ingredient of the preparation triggers a cascade of defense reactions in the plant organism that suppress the development of pathogens.

The mechanism of action of the preparation is based on the following processes:

• Destruction of fungal cell walls: upon penetrating plant cells, the preparation stimulates the production of chitinolytic enzymes (chitinases and chitosanases) that break down the chitinous shell of pathogens.
• Blocking development: it induces the synthesis of plant lectins, under the influence of which the pathogen loses the ability to normal ontogenesis.
• Activation of oxidative stress for the pathogen: it provokes the formation of reactive oxygen species (О₂⁻, ОН⁻, Н₂О₂, О), which accelerate the destruction of fungal cell structures.
• Suppression of reproduction: it stimulates the synthesis of pathogenic fungal proteinase inhibitors, stopping mycelium growth and spore formation.
• Mechanical barrier: it forms a breathable film on the plant surface, which allows gases to pass through but is impassable for the growth tubes of the mycelium.

Adherence to the regulation for preparing the working solution guarantees an even distribution of the active ingredient. The mixture must be prepared immediately on the day of application. Below is a step-by-step instruction for treating one hectare of plantings.

1. On the day of treatment, prepare a stock solution: thoroughly stir 1 kg of dry "Narcissus" powder in 10 L of hot water at a temperature of 85–90 °C.
2. Pour the resulting solution into the tank through a mesh filter.
3. Add hot water again to the residue remaining on the filter. Repeat this procedure until the preparation has completely dissolved.
4. Bring the total volume of the working solution in the tank to 4800 L with water, monitoring the mixture temperature — it should be 20–22 °C.
5. Before planting the transplants, water the planting holes with the first half of the solution (2400 L/ha) at a rate of 150 ml per one hole.
6. Plant the crops with a slight burial of the root collar and immediately water them with the remaining part of the solution (150 ml per plant, consumption rate — 2400 L/ha).
7. During the growing season, carry out two more root applications with a similar solution (300 ml per plant) at one-month intervals.

The effectiveness of the preparation has been confirmed by industrial trials on vegetable and ornamental crops in greenhouse conditions. Treatments were carried out both preventively and upon the appearance of the first signs of diseases. The obtained results prove the high biological and economic return from using the product.

• Against root-knot nematode: when treating cucumber cultivar F1 Marinda in the second rotation (application rate — 25 L/ha), the number of severely affected plants (3–4 points on a five-point scale) in the experimental variant was only 6% compared to 49% in the control. The yield increase was 0.21 kg/m² (9%).
• Against powdery mildew: treatment of cucumbers of cultivars F1 TSKhA 2693 and F1 TSKhA 1417 in the first rotation at a dose of 10 L/ha at the first signs of the disease stopped the appearance of new signs of the disease on day 4–5 after treatment and until the end of the rotation.
• Complex protection: spraying cucumbers, tomatoes, and roses at the first symptoms of powdery mildew at a dose of 5 L/ha led to the suppression of disease development.

• Water temperature for dissolution — 85–90 °C
• Temperature of the prepared solution — 20–22 °C
• Irrigation at planting — 150 ml/plant
• Irrigation during growing season — 300 ml/plant
• Reduction of nematode damage — from 49% to 6%

Symbiont preparation: growth stimulation and stress protection

Preparations of the "Symbiont" series are created based on the metabolic products of endophytic fungi isolated from the roots of ginseng ("Symbiont-1") and sea buckthorn ("Symbiont-2"). These biological agents combine the functions of powerful growth stimulants and immunomodulators. "Symbiont-1" contains a complex of phytohormones (auxin, abscisic acid, and at least four types of cytokinins), as well as monosugars and vitamins.

Regular use of the stimulant ensures a complex effect on the crop. Physiologically active substances stimulate cell division and accelerate metabolic processes. As a result, the plant tolerates unfavorable environmental conditions better.

• Increases field emergence of seed and survival rate of cuttings by 10–15% due to the activation of root formation and photosynthesis.
• Enhances plant resistance to diseases and also increases their drought and frost resistance.
• Provides a yield increase of 20–30% and accelerates product ripening by 7–10 days.
• Reduces the content of nitrates, heavy metals, and radionuclides, helping plants to absorb fertilizer more efficiently.
• Has a noticeable positive effect on increasing leaf biomass.

The preparation "Symbiont" is supplied by reliable manufacturers. This stimulant is produced by companies ZAO "Agro-MDT", ZAO "Vostok-Center" and ZAO "Vostok-MDT". Purchasing original products guarantees the stated effectiveness on crops.

Effectiveness. The symbiont was used to protect cucumber cultivars Estafeta and NIOKh-412 from spider mites in greenhouse conditions in combination with Bicol. Treatment was carried out twice with an interval of 10 days during low spider mite infestation of plants (up to 10%). It was shown that the integrated method, combining both biological products, allows for almost complete protection of plants from spider mites. For example, cucumber yield reached 96.6% of the level of the uninfected plot, while protection with just one biological product ensured a yield of 89.7%. Cucumber ripening, the achievement of technical maturity, was noted one week earlier (Nugmanova et al., 1999).

Toxicological characteristics. Hazard class — UP. No waiting period. Manufacturer: ZAO Selkhozpolimer

Active ingredient — sodium salts of humic acids (300 g/kg). In addition, humates contain a significant amount of amino acids.

Intended for enhancing growth, adaptation to adverse environmental impacts, reducing nitrate content and increasing resistance to diseases.

Mechanism of action. The preparation possesses growth-stimulating and fungicidal properties. The use of sodium humate promotes a faster ontogenesis, thereby shortening the period of age-related vulnerability of plants to root rots. Seed treatment reduces the infection of seedlings with root rots by 4-4.6 times.

Fungicidal properties are expressed in the ability to retard the linear growth rate of fungi by 3-4 days; the formation of conidia is delayed by 1.5-2 days, while the number of formed conidia decreases by 1.5-2.2 times. Sodium humate also inhibits the germination of fungal conidia. For example, the viability of *F. oxysporum var. orthoceras* conidia decreased by 25-30%, and *Botrytis cinerea* — by 3.3 and 1.7 times. At a concentration of 0.001%, sodium humate completely suppressed the germination of conidia of the tomato powdery mildew pathogen tomato. In the control, 12.3% of conidia germinated within 18 hours. After 42 hours, the number of germinated conidia was 3.8 times less than in the control, and at a preparation concentration of 0.01 and 0.1%, complete suppression of conidial germination and even their hyperplasia were observed. TABLE 32. REGULATIONS FOR THE APPLICATION OF SODIUM HUMATE PREPARATION List of PESTICIDES and AGROCHEMICALS... 2001 Crop Application rate Working solution rate Time and frequency of treatments 2.5 kg/ha, 1.7 g/10 l water (L) 15 thousand l, 5 l/m² (L) Soil irrigation when planting plants in soil Soil irrigation after sowing seeds, three Eggplant 1 tab./ 50 l water (L) 5 l/m² (L) subsequent irrigations with an interval of 15 days and soil irrigation when planting in soil Cabbage, head 2.1 kg/ha, 1.5 g/10 l water (L) 14 thousand l/ha, 5 l/m² (L) Soil irrigation after sowing seeds, after 10 days and 5 days before planting in soil 5 l/10 l water (L) Soil irrigation after sowing seeds, from Tomato 1 tab./ 50 l water (L) 5 l/m² (L) the moment of emergence, again after 15 days Increasing resistance to diseases Soil irrigation after planting plants 25 g/ 100 m² 15 thousand l/ha top dressing in the budding phase and at the beginning of flowering 300 mg/kg 1 g/10 l water (L) 1 l/kg Seed soaking for 24 hours Cucumber 2.5 kg/ha, 1.5 g/10 l water (L), 1 tab./ 60 l water (L) 15 thousand l/ha, 5 l/m² (L) Soil irrigation after sowing seeds, then after 15 days and after 20 days All beneficial microelements, being metals with variable valence, form chelate complexes with humates in the soil, which makes mineral elements available to plants. Heavy metals, the ingestion of which through fruits into the human body leads to diseases, form insoluble compounds with humates. This creates a natural barrier to their penetration into plant cells. Spraying crops with humates accelerates not only the growth of green mass but also strengthens the root system and, consequently, provides the plant with complete nutrition. Humates, by increasing the permeability of the cell membrane, facilitate the accumulation of potassium in the cytoplasm.

Humic substances possess a non-specific protective effect. They are characterized by a radioprotective effect and also contribute to reducing the content of pesticides and nitrates in air, water, and soil.

Application features. With prolonged use of greenhouse soil, parasitic forms begin to predominate in the soil microbiota. When growing tomato in such soil, root and stem rots, various types of tracheomycosis and tracheobacterial wilting, southern late blight, meloidogynosis, and a number of other diseases progress.

To reduce losses, soil irrigation and substrate irrigation are recommended (with a 0.015% working solution, consumption 0.75 g of preparation/m²); in addition, good results were obtained from seed treatment in a 0.03% solution (consumption — 1 l/kg of seed) and spraying plants during the growing season, consumption — 200 g/ha of the preparation.

Seed treatment alone did not affect plant infection during the growing season with root-knot nematode, gray mold, southern late blight, and powdery mildew. Seed treatment in combination with monthly irrigation with the preparation solution (application rate 2-3 kg/ha) and spraying with a 0.01% solution (consumption 0.2-0.3 kg/ha) reduced both root-knot nematode infection and the complex of diseases.

To accelerate fruit ripening and increase yield, tomato seeds are soaked before sowing for 72 hours in a 0.01% sodium humate solution. Soil irrigation with a 0.005% sodium humate solution in the nursery after sowing, transplanting, and then again after 15 days is also effective.

Preparation effectiveness. Laboratory emergence of treated seeds increases by 1.8-5.8%, the length of the main root increases by 28.3-34.6%, the number of lateral roots — by 14.6%, and the root hair zone — by 3.5-4.1 mm. As a result of enhanced root development, the above-ground part increases. Distribution in the plant. Aliette is characterized by high mobility in plants; it is quickly absorbed by young shoots, the root system, and moves both acropetally and basipetally, i.e., it has the ability to move not only through the xylem but also through the phloem. When spraying plant leaves or injecting into the stem or trunk of trees, the active ingredient is redistributed throughout the entire plant and has a protective effect not only on phylloplane pathogens but also on pathogens of underground organs.

Mechanism of action. Fungicide of systemic protective and curative action, increases plant resistance to diseases by stimulating the formation of phenols and flavonoids; it also possesses direct fungitoxicity to pathogens: it reduces the quantity or completely suppresses the formation of conidia and delays the release of zoospores. Often, the resulting conidia have increased size and reduced germination capacity. Preparations of this group are capable of inhibiting oospore formation, for example, in Ph. nicotianae var. parasitica.

The toxic effect of fosetyl-aluminium on pathogens is associated with the formation of phosphorous acid (H3PO3) inside the plant. Like fosetyl-aluminium, it suppresses the formation of oospores and sporangia, and the release of zoospores of various types of pathogens, but at a lower concentration (EC50 — 1-6 mcg/ml) it inhibits mycelial growth (EC50 — 1-224 mcg/ml), delays the germination of encysted zoospores (EC50 — up to 100 mcg/ml) and the formation of chlamydospores (EC50 — 14-44 mcg/ml).

Advantages of the preparation. Prolonged use of Aliette was not accompanied by the development of resistance in pathogens. The preparation provides more reliable and long-lasting protection than contact fungicides, allows for a reduction in the number of treatments, and protects the entire plant and newly emerging growth. Penetration into the plant occurs within 15-30 minutes. The preparation is resistant to rain wash-off, and its protective effect lasts up to three weeks.

Application features. Plants should be treated upon the appearance of the first symptoms of disease, which blocks pathogen development and prevents the spread of the disease. In this regard, preparations based on fosetyl-aluminium should be used mainly preventively.

Toxicological characteristics. The manifestation of fosetyl-aluminium (as well as phosphorous acid) toxicity is associated with the effect on cell membrane permeability, lipid and phospholipid metabolism, and pathogen cell wall synthesis. It is low-toxic to warm-blooded animals and has a local irritating effect on the skin. Metabolites are non-toxic and do not pollute the environment. Aliette is not dangerous to poultry. Hazard class — III. Waiting period — 20 days. Manufacturer: Aventis CropScience S.A. TABLE 36. REGULATION OF ALIETTE PREPARATION APPLICATION List of PESTICIDES and AGROCHEMICALS... 2001. Method and timing of treatment. Spraying during the growing season, Strawberry (nurseries). Leather rot, late blight, and fruit rot with Efals working solution, SC. Active ingredient: fosetyl-aluminium (650 g/l), belongs to the group of fungicides derived from phosphonic acid.

The preparation is analogous to Aliette, but with a lower content of active ingredient and is recommended for the protection of cucumber during the growing season (usually in the second crop rotation). Initially, the transplants of susceptible hybrids/cultivars are sprayed at the 4-5 leaf stage, then twice after planting the plants in a permanent location at intervals of 15-20 days. For resistant hybrids, it is sufficient to treat once two weeks after planting in a permanent location (37).

TABLE 37. REGULATION FOR THE APPLICATION OF THE PREPARATION EFAL List of PESTICIDES and AGROCHEMICALS... 2001 Method and time of treatment Cucumber 3 Downy mildew | with working solution at intervals of 15-20 days (three times). Consumption 1000-1500 l/ha Waiting period: three days. Hazard class — III. Manufacturer: OOO Agropromkhimsnab Fundazol. SP d. — benomyl (methyl-N-(butyl-carbamoyl-2-benzimidazole)-carbamate (500 g/kg). White crystals with a faint odor. Non-volatile. Insoluble in water, highly soluble in organic solvents. On the surface of plants, under the influence of UV and humidity, it decomposes to the active ingredient (BCM), which protects the plants for a long time. Intended for controlling powdery mildew and fungi causing vascular diseases (table 38). Also effective against clubroot of crucifers.

Distribution in the plant. Moves through the plant only via the xylem from bottom to top; it is absorbed by leaves, stems, and roots. It penetrates the soil via capillaries to a depth of up to 20 cm.

Mechanism of action. Fundazol, like other benzimidazoles, inhibits the division of fungal cells by binding to the main structural protein of microtubules (tubulin), thereby disrupting chromosome segregation. The preparation is effective against certain groups of fungi (most ascomycetes, deuteromycetes, some species of basidiomycetes), but oomycetes and zygomycetes (mucorales) are insensitive to it.

Features of the preparation. A systemic and contact fungicide possessing both curative and protective effects. Currently, it is most appropriate to use it for seed treatment, which is due to the emergence of resistance in many phytopathogenic fungi. In the soil, the preparation does not decompose for 1.5-2 years and is capable of suppressing the development of root rot pathogens for a long time.

Features of application. When used correctly, Fundazol is non-toxic to plants, but has a toxic effect when applied to the soil in excessive doses. Frequency of treatments — up to four times per season.

Toxicological characteristics. Waiting period 10 days. The preparation is moderately toxic to warm-blooded animals. Hazard class III. Manufacturer: Agro-Kemi Kft.

Method, time of treatment, wilting: with solution of Vectra, SC.

Active ingredient — bromuconazole (100 g/l).

Intended for controlling leaf spots on various crops, but in greenhouse conditions, it is registered only for flower crops.

Waiting period: three days. Five-time treatment of plantings is permitted. Manufacturer: Aventis CropScience S.A.