PL
W chemicznej ochronie zbóż stosowane są g łównie fungicydy azolowe, morfolinowe, strobilurynowe, benzimidazolowe oraz inhibitory dehydrogenazy kwasy bursztynowego. Fungicydy azolowe i morfolinowe są inhibitorami biosyntezy steroli (SBI). Fungicydy strobilurynowe (QoI) i inhibitory dehydrogenazy kwasu bursztynowego (SDHI) zaburzają proces oddychania grzybów, a benzimidazolowe (MBC) tworzenie ß-tubuliny podczas mitozy. W populacjach wielu patogenów zbóż wykryto formy odporne na wszystkie grupy fungicydów, jednak niebezpieczeństwo powstawania tych form dla fungicydów strobilurynowych i benzimidazolowych jest szczególnie duże. Większość fungicydów strobilurynowych wyróżnia się mniejszą trwałością w glebie i większą podatnością na wymywanie. Toksyczność fungicydów wobec Daphnia magna określona wskaźnikiem ED50 waha się w poszczególnych klasach fungicydów w następujących zakresach: 1,3–51 (azole), 1,3–25 (morfoliny), 0,011–1,3 (strobiluryny), 0,044–100 (SDHI), 0,15–5,4 ml·l⁻¹ (bezimidazole). Sporadycznie literatura opisuje również przypadki endokrynnego działania azoli lub rakotwórczego wpływu benzimidazoli na zwierzęta. Alternatywą dla fungicydów mogą być przyjazne środowisku preparaty indukujące odporność systemiczną roślin (SAR), rzadko stosowane w ochronie zbóż przed patogenami.
EN
Major fungicides groups used in chemical plant protection are: azoles, morpholines, strobilurins (QoI), benzimidazoles and thiophanates (MBC) and succinate dehydrogenase inhibitors (SDHI). In recent years, SDHI popularity continues in grow because of its efficiency. Among active SDHI chemicals there are long-known substances, e.g. carboxin, fenfuram and new synthesized compounds. Modes of action of each fungicide groups are different and their classification is based on specific active compounds mechanism of action. Azole and morpholine fungicides are inhibitors of sterol synthesis. One of the main sterols in fungal cells is ergosterol which is an important building compound in cell wall. Ergosterol is necessary to maintain cell membrans proper functions. Strobilurins and succinate dehydrogenase inhibitors interrupt respiratory chain in fungal cells by blocking electrons transfer. Strobilurins connect with ubichinon coenzyme in cytochrome b and c1 whereas SDHI connect with succinate dehydrogenase complex. Benzimidazoles and thiophanates inhibit synthesis of β-tubulin during mitosis. Crop pathogens resistance to all these active compounds has been discovered so far. The most serious hazard of pathogen resistance acquisition is a characteristic of benzimidazole and strobilurin fungicides. There is high probability of forming resistant pathogens due to new fungicides production. There are four major resistance mechanisms in fungi: (1) change in target site (mutations), (2) metabolic detoxification of active substance, (3) production of the additional enzyme target site, (4) removal of the target site. Durability in soil is determined by half-life time (DT₅₀) of active compounds: azoles 1.6–120, morpholines 21–49,5, strobilurins 7–180.5, SDHI 3.5–118.8, benzimidazoles and thiophanates 5–724 days. Short period of half-life time of selected strobilurins is linked with susceptibility to eluviation. Fungicides toxicity to Daphnia magna is defined as EC₅₀ index which varies between each group of fungicides, e.g.: azoles 1.3–51, morpholines 1.3–25, strobilurins 0.011–1.3, SDHI 0.044–100, benzimidazoles 0.15–5.4 ml L⁻¹. However, several case reports of azoles endocrine and benzimidazoles carcinogenic effects on animals have been reported. Environmentally friendly alternative for chemical plant protection are preparations inducing systemic acquired resistance (SAR). Salicylic acid (SA), 2,6-dichloroisonicotinic acid and gamma-aminobutyric acid (GABA) and chitosan are inducers (called elicitors) of SAR in plants. The main advantage of preparations containing elicitors is no risk of pathogen resistant forms spread. So far, such preparations are not often used in crops protection.