Regulations for the application of Rovral and Kemicar fungicides in plant protection

Method and time of treat. Spraying during the period, Rovral. Active ingredient — iprodione (500 g/kg), a heterocyclic compound from the dicarboximide group. Light-colored powder.

Intended for the control of grey and white rot pathogens on vegetable and ornamental crops, especially against strains of pathogens resistant to benzimidazoles.

Distribution in the plant. A contact preparation; however, it retains its stability when absorbed by roots.

Mechanism of action. Iprodione suppresses the germination of fungal spores and blocks the development of their mycelium; it inhibits the incorporation of thymidine into DNA, suppresses the synthesis of 4-dimethylated sterols and the chitin synthesis of the cell wall, but does not reduce the permeability of the cytoplasmic membrane.

Application features. Bulbs are soaked in a 0.2% suspension of the preparation immediately before planting in the soil. Spraying of bulbous seedlings is carried out at the first signs of rotting of bulbs or flowers, in which case maximum effect is achieved. Four treatments per season are allowed.

There is experience in painting affected stems with a special paste. Proportion for preparing the paste: 300-340 g of CMC glue and 30-40 g of fungicide are added to 10 L. The mixture is brought to a pasty state by adding [water]. Painting of botrytis spots should be done carefully, covering 2-3 cm of outwardly healthy tissue (Yuvarov, [Year]). The procedure is repeated in damp, rainy weather, usually after two weeks due to the appearance of new [lesions].

TABLE 40. APPLICATION REGULATIONS FOR ROVRAL PREPARATION List of PESTICIDES and AGROCHEMICALS... 2001. Method and time of treat. Painting affected stems... chalk in a ratio of 1::

2-4 Bulb treatment. Flower bulbous Grey rot with the working solution, possible for [the] crop, repeated spraying of plants during the growing season.

To reduce the likelihood of phytopathogen resistance to the preparation, it should be alternated with treatment of plants using benzimidazoles.

Toxicological characteristics. It decomposes rapidly in the soil into non-toxic metabolites. Hazard class IV. Manufacturer: Aventis CropScience S.A.

Active ingredient — carboxin (750 g/kg), belongs to the carboxamide group.

Mechanism of action. Carboxin is a specific inhibitor of mitochondrial respiration, acting on the succinate-ubiquinone reductase complex II, interrupts electron transport in the Krebs cycle; as a result, growth of fungi decreases due to a reduction of energy in the cells. Formation of resistant fungal strains is possible due to a decrease in the sensitivity of the succinate dehydrogenase complex.

Application features. Kemikar is a systemic fungicide used for the preparation of simple and mixed seed treatment preparations (often in a mixture with thiram); it is most effective in controlling basidiomycetes (smut and rust phytopathogens) and some imperfect fungi (e.g., Rhizoctonia solani, Rhizoctonia sp.). The preparation has a prophylactic and curative protective effect.

TABLE 41. APPLICATION REGULATIONS FOR KEMIKAR PREPARATION List of PESTICIDES and AGROCHEMICALS... 2001. Method and time of treat. Bulb treatment before planting.

Intended for the seed treatment of bulbs of tulips and narcissi before planting in the soil.

Toxicological characteristics: it decomposes rapidly in the external environment and is of low toxicity to humans and warm-blooded animals. Manufacturer: Kemira Agro.

Active ingredient — mancozeb (600 g/kg) + dimethomorph (90 g/kg). A combined preparation containing a contact fungicide — mancozeb and a systemic one — dimethomorph, which belongs to morpholine derivatives. However, in terms of biological activity, fungitoxicity, and mechanism of action, this preparation is closer to cinnamic acid derivatives. Dimethomorph is an odorless crystalline substance with a melting point of 127-148°, stable at high temperatures and in an aqueous medium.

Intended for the control of downy mildew and Pythium fungi; it possesses specific activity against late blight of tomatoes. Dimethomorph is effective against strains of late blight pathogens resistant to phenylamides. It acts at all stages of disease development and protects leaves, stems, and fruits. Precipitation occurring 1-2 hours after treatment does not reduce its efficacy.

Mechanism of action. Dimethomorph alters the natural morphogenesis of the cell wall, which leads to the disruption of the normal development cycle of the oomycete; it possesses an anti-sporulation effect. The preparation has both systemic and contact action.

Distribution in the plant. Almost completely absorbed by the plant 1-2 hours after treatment, moving only acropetally and translaminarly.

Application features. Especially reliable protection of crops is ensured by treating plants before the appearance of signs of their infection. The duration of the protective effect is 10-14 days. Consequently, treatments during the growing season are repeated every 10 days. As with other systemic fungicides, oomycetes develop resistance to dimethomorph, however, cross-resistance between dimethomorph and phenylamides is not observed.

TABLE 42. APPLICATION REGULATIONS FOR ACROBAT MC PREPARATION List of PESTICIDES and AGROCHEMICALS... 2001. Method and time of treatment. Spraying during the period with a solution.

Toxicological profile. For warm-blooded animals, the preparation is of low toxicity and does not irritate mucosal membranes. Hazard class — TU. Manufacturer: BASF AG. Ridomil MC, WP and Ridomil Gold, WG.

Active ingredient: metalaxyl (80 g/kg) + mancozeb (640 g/kg). A combined preparation containing substances with different mechanisms of action. Mancozeb possesses good adhesiveness, is transported through xylem vessels from bottom to top, and is capable of inhibiting spore germination and mycelium growth in the plant.

Metalaxyl-M and the Ridomil product line: systemic protection against downy mildew and late blight

Metalaxyl belongs to the acylalanine group, while its constant partner, mancozeb, belongs to the alkylbis(dithiocarbamate) group. Chemically pure metalaxyl consists of crystals with a melting point of 71–72 °C; it is poorly soluble in water, readily soluble in organic solvents, and stable in acidic and neutral media. Of the two stereoisomers of the substance, only the R-enantiomer possesses fungitoxicity, whereas the S-enantiomer is practically inactive. It is based on the R-enantiomer that active ingredient metalaxyl-M was created, which is used in the Ridomil Gold preparation. The new formulation, Ridomil Gold WG, rapidly forms a stable working suspension when preparing the solution.

The preparations Ridomil MC, WP and Ridomil Gold MC, WG are intended for the control of pathogens causing downy mildew, late blight, and other pathogens. Metalaxyl penetrates leaf and stem tissues within 30 minutes after spraying and moves acropetally, protecting new growth from Pythium and Phytophthora species. During seed treatment, the main part of the fungicide accumulates in the seed coat, embryo, and periphery of the endosperm, and upon germination, it is redistributed into cotyledons and seedlings. The preparation blocks the pathogen's RNA biosynthesis, causing ultrastructural changes in fungal cells 24 hours after the penetration of haustoria. Metalaxyl also stimulates the plant's defense responses, inducing the formation of necroses and the accumulation of phytoalexins.

The preparation is of low toxicity to bees and of moderate toxicity to warm-blooded animals. It does not accumulate in tissues and is rapidly excreted from the body: up to 60% of the substance is excreted within 2 hours. At the same time, the fungicide retains activity in potatoes for up to 35 days, and in the soil — from 40 to 70 days with a half-life of one month (20–30 days). For cucumbers, three treatments are permitted with a 3-day waiting period.

• Penetration into leaf tissue — 30 min
• Half-life in soil — 20–30 days
• Waiting period on cucumbers — 3 days
• Retention of activity in the plant — up to 15 days
• Fungicidal activity in soil — from 8 to 20 weeks

Oxadixyl and Sandofan M 8: synergism of components and eradicant action

The preparation Sandofan M 8, WP from the manufacturer Syngenta contains contact mancozeb (560 g/kg) and contact-systemic oxadixyl (80 g/kg) from the acylalanine group. Oxadixyl is a solid crystalline substance with a melting point of 104–105 °C; it is non-volatile, readily soluble in water, and stable during storage. Its mechanism and spectrum of action are analogous to metalaxyl; however, pronounced synergism of the components is observed in combined preparations with oxadixyl. The protective activity of the preparation in the soil lasts from 8 to 20 weeks, and within the plant — up to 15 days.

Sandofan M 8, WP effectively combats damping-off in cucumbers caused by fungi of the Pythium genus, although its efficiency on this crop is inferior to metalaxyl. At the same time, in the protection of tomatoes against late blight, the efficiency of both active ingredients is identical. Oxadixyl has a shorter period of therapeutic action compared to metalaxyl, but it possesses a more pronounced eradicant effect.

Oxadixyl practically does not evaporate from treated leaves: 94% of the applied active ingredient remains at the point of contact. It rapidly penetrates internal tissues and is transported with sap to all untreated parts of the plant. The preparation moves in all directions — acropetally (towards leaf tips), basipetally, translaminarly (from the upper side of the leaf blade to the lower), and laminarly (from one side of the leaf to the other), being almost completely redistributed into new growth.

For warm-blooded livestock animals, oxadixyl is of low toxicity, does not irritate mucosal membranes, and is excreted from the body via urine and feces. The active ingredient is safe for poultry and presents low risk to bees. The risk of phytotoxicity appears only at extremely high doses (to a significantly lesser extent than with metalaxyl), which makes the preparation highly safe for crops. In the soil, oxadixyl decomposes slowly.

• Hazard class — III
• Waiting period — 3 days
• Frequency of application — 3–4 times
• Manufacturer — Syngenta AG

Mancozeb (800 g/kg) is a powder from the alkylbis(dithiocarbamate) group, practically insoluble in water and most organic solvents. It is a mixture of zinc (2.5%) and manganese (16–20%) ethylenebisdithiocarbamates. The mechanism of action is based on the inhibition of vital enzymes in fungal cells, which ensures efficacy against most Ascomycetes, Oomycetes, Deuteromycetes, and Basidiomycetes.

In field conditions, mancozeb serves as an essential component of mixture fungicides (such as Ridomil MC, Ridomil Gold MC, Acrobat MC). It significantly reduces the risk of pathogens developing resistance to systemic components. In greenhouses, the use of pure mancozeb is prohibited — it is used there only as part of combination preparations.

• Hazard class — IV
• Waiting period — 30 days
• Manufacturer — Rohm and Haas

Regulations for the use of copper-based fungicides

Cuproxat (suspension concentrate based on copper sulfate, 345 g/l) is intended for the control of various leaf spots. Its spectrum of application for open ground is wide. However, in greenhouses, the preparation is registered exclusively for the protection of roses.

• Active ingredient content — 345 g/l
• Hazard class — III
• Manufacturer — Nufarm GmbH & Co. KG

1. Remove bacterial growths on the rose roots.
2. Immerse the roots for... min in a 1% working solution of the preparation (at a rate of 500 g per 10 l of water).
3. Thoroughly rinse the treated roots with clean water.

Bordeaux mixture (active ingredient — copper sulfate + calcium hydroxide) remains one of the most reliable and well-studied contact fungicides. It effectively protects crops from a wide range of fungal diseases. The preparation adheres excellently to the leaf surface, ensuring a prolonged protective period.