Differently Directional Effects of Tebuconazole-Based Disinfectant of Seeds “Bunker” on the Growth of Winter Wheat Shoots and Roots

Abstract

Derivatives of a triazole are used not only as fungicides to prevent infection of plants, but also for treatment. These drugs are actively used against plant diseases caused by basidiomycetes, ascomycetes, and some deuteromycetes. Due to their chemical stability, they have a long-term protective effect, and their solubility in water ensures their movement from the roots to the aerial part of plants. The aim of this work was to study the effect of seed treatment with tebuconazole-containing preparation “Bunker” on the growth of shoots and roots of winter wheat in the light and physiological and biochemical parameters. We used a fungicide of prophylactic and therapeutic action tebuconazole-containing seed treater “Bunker” (August, Russia), the active ingredient of which is tebuconazole (60 g/L). The shoot length and total root length, wet and dry biomass, as well as the content of photosynthetic pigments, reactive oxygen species – hydrogen peroxide (H2O2) and lipid peroxidation products (LPO) reacting with thiobarbituric acid (TBA-RP) in the tissues of shoots and roots were analyzed. The content of chlorophylls a and b and carotenoids in the extract was determined spectrophotometrically at wavelengths of 665, 649, and 440 nm, respectively. The obtained results indicate that the action of the drug is aimed at inhibiting the growth of shoots and reducing the ratio of shoot length to root length, while on the 7-9th day of growth, the effectiveness of its action is higher, and the most significant effect is exerted by an increased dose of the disinfectant (1.5 μL/g). It was found statistically significant stimulation of root growth on the 9th day of cultivation, regardless of the dose of the dressing agent. Despite the significant growth-inhibiting effect, treatment with Bunker was not accompanied by activation of oxidative processes in shoot tissues, with the exception of an increase in the content of H2O2 and TBA-RP at the initial stage of growth (5 days). In root tissues, the content of H2O2 and TBA did not change under the action of the studied preparation. No differences in the content of chlorophylls a and b and carotenoids in the tissues of wheat shoots after treatment with the studied fungicide were found. Based on the data obtained, it can be concluded that seed dressing agents containing tebuconazole as an active ingredient can be used to ensure plant resistance to moisture deficiency and improve mineral nutrition.

Comparison of Presowing Wheat Treatments by Low-Temperature Plasma, Electric Field, Cold Hardening, and Action of Tebuconazole-Based Disinfectant

“…The criterion for the quality of processing was the effect on the frost resistance and morphophysiological characteristics of the seedlings. However, the proposed mechanisms of the physiological effects on seeds with a tebuconazole-based seed disinfectant can be found in [22,23]; cold hardening in [19]; electric field in [15,16]; and plasma in [8][9][10][11][12][13][14].…”

“…To test the concept of the compatibility of plasma and chemical treatments, in this work, we chose a tebuconazole-based seed disinfectant, "Bunker" (water suspension concentrate, content of tebuconazole is 60 g/L, JSC "August" Inc., Moscow, Russia ) [18]. There is a great deal of technical information on the use of the disinfectant, including in field studies [19][20][21][22][23]. The effect of disinfectants, including the disinfectant "Bunker", on the quality of the winter wheat crop Moskovskaya 39 (Triticum aestivum L., variety Moskovskaya 39), cultivated for sowing seed purposes, was determined in [21] in a three-year experiment on plots of 25 m 2 .…”

“…Throughout the entire growing season, "Bunker" protected plants from root rot. Long-term protection of the plant from diseases, due to the chemical stability of the agent, is also noted in the work [22]. On the seedlings of spring soft wheat Tulunskaya 12 (Triticum aestivum L., variety Tulunskaya 12) [20] and soft winter wheat Irkutskaya (Triticum aestivum L., variety Irkutskaya) [22], the effect of various concentrations of the "Bunker" disinfectant was studied.…”

“…Long-term protection of the plant from diseases, due to the chemical stability of the agent, is also noted in the work [22]. On the seedlings of spring soft wheat Tulunskaya 12 (Triticum aestivum L., variety Tulunskaya 12) [20] and soft winter wheat Irkutskaya (Triticum aestivum L., variety Irkutskaya) [22], the effect of various concentrations of the "Bunker" disinfectant was studied. On both spring and winter wheat, with an increase in the concentration of the disinfectant, an increase in the growth-inhibiting effect was observed, but when exposed to spring wheat, the growth of both the aboveground and underground parts of the plant slowed down, and when exposed to winter wheat, the growth of the aboveground one slowed down and the growth of the underground one accelerated.…”

“…Pre-hardening by plasma treatment can prevent cold hardening. It is also known that the use of a tebuconazole-containing disinfectant does not interfere with cold hardening, which imitates these natural conditions [19,22].…”