Decrease of the negative impact on environment of protectants of seed which contain tebuconazole and prochloraz for sustainable agricultural development

Abstract

Fungi that parasitize plants are capable of producing plant toxins - phytotoxins. One of the producers of phytotoxins is the hemibiotrophic fungus Pyrenophora sp. Phytotoxins inhibit cell division, suppress or enhance respiration, disrupt synthesis, transport, membrane functions, inhibit enzymes, exhibit hormonal activity - they produce phytohormone abscisic acid. Many fungicides, in addition to the protective effect, have a toxic effect both independently and indirectly, through the effect on the production of toxins by the fungus. We propose to call the first property toxicity, the second - toxigenicity. The aim of this work was to clarify the inhibitory effect on plant growth and the toxigenic effect on phytopathogenic fungi tebuconazole and prochloraz. Tebuconazole and prochloraz in the doses used had a fungistatic effect. The synergistic effect is revealed. Since the effect of tebuconazole was greater than that of prochloraz, it would be prudent to reduce the dose in the dressing agent. The optimal ratios were 1: 5; 3: 1; 3: 3. At high doses of tebuconazole, the synergistic effect with prochloraz was not manifested. The toxicity of the prochloraz solution for seedlings was higher than the toxicity of tebuconazole; both those a.i. did not significantly affect the shoot/root ratio, did not change the hormonal balance. The most favorable ratios were tebuconazole: prochloraz 1: 2, 3: 2. The toxicity of prochloraz for the mycelium of Pyrenophora sp., assessed by the biotest, was higher than the toxicity of tebuconazole. Inhibition of root growth was noted. The least toxigenic ratios were tebuconazole: prochloraz 3: 2 and 5: 4. According to the complex of features, the ratio tebuconazole: prochloraz 3: 2 is the most effective, least toxic for plants and toxigenic for the phytopathogenic fungus Pyrenophora sp.

Efficacy and phytotoxicity of various thiabendazole and tebuconazole ratios in a fungicidal mordant

“…Fungicides, having a direct toxic effect on plants, enhance the production of toxins by fungi, which causes similar toxic effects. In this case, we should not talk about toxicity, but about the toxigenicity of the fungicide [14].…”