Fungicide protection of winter wheat from DEFENDA

Throughout ontogenesis, winter wheat plants can be affected by various diseases, which leads to reduced yield and grain quality. Disease losses amount to at least 10-20% of potential yield. Due to the current intensification of production, the harmfulness of pathogens is increasing, and losses may exceed 50%.

Today, the most widespread harmful diseases of winter wheat are septoria leaf blotch, tan spot (pyrenophora), rusts, powdery mildew, septoria and fusarium head blight, as well as alternaria. They are the target objects when planning a fungicide protection system.

In the winter wheat protection system, there are 4 fungicide application timings, which coincide with the crop's critical periods of vegetation and yield formation:

• T0 - application during tillering (BBCH 21-29).
• T1 - application at the beginning of stem elongation (BBCH 30-32).
• T2 - application from flag leaf emergence to ear development (BBCH 37-49).
• T3 - application during heading-flowering (BBCH 51-69).

However, heavy rainfall this year creates a risk of disease infection of winter wheat plants during grain filling and ripening (BBCH 71-90). Therefore, it is necessary to carry out an additional fungicide treatment preventively or at the first signs of disease at the beginning of grain filling (BBCH 71-80) – T4.

The DEFENDA brand has a wide range of effective fungicides in its portfolio that keep winter wheat plants healthy throughout the entire organogenesis.

The product ABSOLIUT (carbendazim, 500 g/l) is a systemic fungicide and seed treatment with protective and curative action for protecting cereal crops. It provides excellent control of most fungal diseases under a wide variety of climatic conditions and is effective with a single application. It has preventive and curative action, stopping disease at an early stage. Absoliut is a traditional component of complex plant protection systems with an extended period of protective action. It is applied during the growing season preventively or at the first signs of infection. To prevent resistance, rotation with fungicides of different modes of action is recommended if multiple treatments are needed during one growing season.

SALTO (thiophanate-methyl, 500 g/l) has fast and at the same time prolonged protective action (over 2 weeks). It is flexible in mixing with other products, except alkaline ones. Thanks to its systemic action, it is quickly distributed throughout the plant. It uniquely combines preventive and curative action, has an eradicating effect and strong action against fusarium, and prevents the formation of mycotoxins.

DOT (80 g/l cyproconazole + 250 g/l propiconazole) is a universal fungicide with excellent preventive and curative action. It is distinguished by uniquely fast penetration into the plant and instant action on pathogens. Thanks to cyproconazole, DOT protects the flag leaf from diseases with one treatment and the ear with a second treatment after flowering. It is compatible with most pesticides used on cereal crops. However, compatibility must be checked in each specific case.

KAMZOL (metconazole, 60 g/l) is a systemic fungicide with protective and curative action for use on small-grain cereal crops. It also promotes the development of a powerful root system and extends the grain ripening cycle, resulting in better grain quality and weight. It increases plant resistance to adverse environmental conditions. One of its advantages is the prevention of plant lodging. The product has long-lasting protective and therapeutic action. It works both preventively and at the first signs of disease, stopping the development of infection. It can be used in tank mixes with most pesticides, but a trial mixing must be carried out beforehand. Mixing the product with pesticides that create a strongly alkaline environment is not recommended.

The systemic fungicide METSENAT (propiconazole, 250 g/l) is used to protect small-grain cereal crops from a complex of leaf diseases. It is distinguished by a broad spectrum of fungicidal action and is highly effective against false fungi (basidiomycetes, ascomycetes and deuteromycetes). It has strong curative action; its activity decreases in cool and wet weather. It is active against powdery mildew for 3-4 weeks, rust for 4-5 weeks, and under epiphytotic conditions for up to 2 weeks. The product is most effective when treatments are carried out preventively or at the first signs of disease development. In the fungicide protection system, it is most advisable to use it for the first treatment of winter wheat at tillering and stem elongation.

The product PARATSELS (flutriafol, 250 g/l) is one of the most mobile products in the triazole group. It is distinguished by long-lasting protective action against a complex of the most harmful diseases. It is flexible in application (regardless of the crop development stage). It is a universal systemic-contact fungicide with protective and curative action. It acts as an inhibitor of nutrient biosynthesis in harmful fungal species, which leads to the destruction of pathogen cell membranes and stops their development. It is applied during the growing season at the first signs of disease. The maximum effect is achieved when applied at the beginning of the crop's stem elongation and again to extend protective action – between flag leaf emergence and the beginning of heading.

TALER (tebuconazole, 250 g/l) is distinguished by curative and preventive effects. It combines the qualities of a fungicide and a growth inhibitor with a pronounced «stop effect». It is a broad-spectrum fungicide for protecting winter wheat, rapeseed and soybeans from powdery mildew, rust, rots, septoria, alternaria and other diseases. The active ingredient quickly penetrates the plant (within 1-2 hours), so effectiveness is guaranteed even if heavy rain occurs after spraying. It works both preventively and after disease infection, remaining effective for several weeks.

The product STARK (azoxystrobin, 250 g/l) is effective against 4 classes of fungi: Ascomycetes, Basidiomycetes, Deuteromycetes, Oomycetes. It ensures no cross-resistance of pathogens. It penetrates to untreated parts of plants. It is rainfast. Penetrating through the leaf blade, Stark protects it on both sides from pathogen penetration. The best effect is achieved when applied before disease development or at its initial stage. It has systemic, preventive-curative, eradicating action and translaminar properties. Its curative action lasts 2 days, which makes it possible to destroy the pathogen during the incubation period.

The fungicide PEHAS (prochloraz, 450 g/l) combines both preventive and curative action. It provides effective disease control at all stages of cereal crop development. Thanks to its locally systemic action, it reliably protects crops from pathogens. It suppresses fusarium head blight by 50% when applied after the appearance of disease symptoms. Prochloraz penetrates all parts of the plant and remains active for up to 4 weeks.

Depending on the pathogen and its spread, the winter wheat protection scheme and the product application rate may vary.

Application rates and timing of Defenda brand fungicides in winter wheat crops

At the same time, to increase the effectiveness of the products, the spectrum of diseases they control must be taken into account.

Therefore, to enhance their action, single-component DEFENDA products are best combined in tank mixes, in particular:

• Kamzol (Metconazole, 60 g/l) 0.4-0.5 l/ha + Metsenat (Propiconazole, 250 g/l) 0.5-0.75 l/ha;
• Taler (Tebuconazole, 250 g/l) 0.5 l/ha + Metsenat (Propiconazole, 250 g/l) 0.5 l/ha;
• Kamzol (Metconazole, 60 g/l) 0.4-0.5 l/ha + Paratsels (Flutriafol, 250 g/l) 0.5 l/ha.

Not under dry conditions:

• Stark (Azoxystrobin, 250 g/l) 0.4-0.5 l/ha + Paratsels (Flutriafol, 250 g/l) 0.5 l/ha;
• Stark (Azoxystrobin, 250 g/l) 0.4-0.5 l/ha+ DOT (Cyproconazole, 80 g/l + Propiconazole, 250 g/l) 0.5 l/ha;

Thus, thanks to the single-component nature of DEFENDA products and their combination, the brand's protection system provides a comprehensive approach to controlling the spread of the most harmful winter wheat pathogens.

Author: Agrotechnology Development Manager in the north-eastern region, PhD in Agricultural Sciences V.O. Ilchenko