Julia Titova

Phytopathogenic fungi of the genus Alternaria cause black spot (helminthosporiasis) disease and therefore apply to develop bioherbicides for controlling weeds and illegal vegetation of narcotic plants such as opium poppy (Papaver somniferum subsp. somniferum). In this report, Alternaria papavericola strain 1.39 was identified using sequencing of the ITS region and characterized. Strain 1.39 produced auxins and abscisic acid, did not produce salicylic, jasmonic, or gibberellic (GA3) acids, and did not metabolize any of these phytohormones. Strain 1.39 produced siderophores but showed no 1-aminocyclopropane-1-carboxylate deaminase activity and did not solubilize phosphates Ca₃(PO₄)₂, Ca-phytate, Al₃PO₄, or Fe₃PO₄. Extracts from the culture liquid of strain 1.39 caused necrosis in leaves of poppy and, to a lesser extent, on creeping thistle, tomato, and wheat leaves. Strain 1.39 inhibited poppy seed germination energy by 80%, reduced shoot biomass by 77%, and resulted in the death of 75% of poppy plants in a pot experiment. The phytotoxin was isolated from the culture liquid of this fungus using chromatographic methods. Detailed study of structure of this phytotoxin by a complex of physicochemical methods revealed that it is (+)-cis-sclerosporide(1S,2S,3S,4R,5S,6R)-2,3,5-trihydroxy-4,6-dimethoxycyclohexyl-(1R,5S,6S)-5-isopropyl-8-methylbicyclo[4.4.0]deca-2,7-diene-2-carboxylate). The results showed possibility for application of A. papavericola 1.39 as bioherbicide against opium poppy.

The use of modern multifunctional biological agents as an alternative to chemicals contributes to increased soil biological activity and suppressiveness. This leads to a decrease in plant disease incidence, an improvement in the phytosanitary condition of agroecosystems, and an increase in yield. The research goal was to evaluate the efficacy of a new multirecycled granular preparation based on Trichoderma asperellum T-36 in protecting spring wheat from diseases and enhancing soil suppressiveness in West Siberia. The tasks were solved on the T-36-based granular biologic prototype developing; 2 years field trials data summarizing, evaluating and statistically processing on phytoregulatory activity and field efficacy of T-36-based granular biologic prototype in spring soft wheat cultivation in West Siberia; qualitative and quantitative indices characterizing of soil microbiota from spring soft wheat rhizosphere in West Siberia conditions; total and induced soil suppressive activity on natural and artificial infection backgrounds with T. asperellum T-36 introduction estimating. In 2 series field trials the T-36-based granular biologic prototype demonstrated phytoregulatory activity: biometric indices of wheat plants development (survival rate, length of shoots and roots, their number, plant height and biomass, leaf area, stand density and bushiness, ear length, number of grains in ear and spikelets, grain weight and yield) under the prototype influence reliably (p ≤ 0.05) 1.2–1.4 times exceeded the control ones. No significant differences in phytoregulatory activity were found in comparison with the registered biologic Sternyphage, WP (wettable powder) as a template reference. Biological efficacy against soil pathogens was 33–56, 41–59%; in the development of leaf-stem infections 25–50, 30–98% for Sternyphage, WP and T-36-based granular biologic prototype respectively. In the phases of crop development from tube emergence to milk ripeness, the highest soil activity in rhizosphere under the prototype influence was reliably (p ≤ 0.01) 2 times higher than the control one. Soil homeostasis indirect evidence in spring soft wheat rhizosphere was obtained, represented by total soil microbiota representatives stability and the saprotrophs trophic group abundance and number stability during all phases of the main crop development as well. High total soil suppressiveness, as well as forming and strengthening of induced suppressiveness by protective biologics (T-36-based granular biologic prototype and Sternyphage, WP) application in all phases of wheat plants development, caused by high antagonists abundance and significant phytopathogens abundance decrease were shown. Successions were revealed in various phases of spring soft wheat holobiont development from 0 day up to the vegetation end, caused by the absence of significant similarity in rhizosphere microbiota complexes in dynamics.

Control systems for opium poppy (Papaver somniferum L.)—an undesirable narcotic-containing plant—must align with the principles of sustainable agriculture. Their priority is using biological agents and reducing the application of chemical pesticides. In the conducted research, the bioherbicidal activity and efficacy of a promising strain A. papavericola 1.39-8 in laboratory prototypes of mycoherbicides applied in combination with chemical herbicides to suppress Papaver somniferum L. were evaluated. Laboratory mycoherbicide prototypes alone caused mortality of up to 35%, and the severity of toxic damage to surviving poppy plants ranged from 24 to 67%: reductions in growth and biomass reached up to 60 and 65%, respectively. A significant increase in efficacy was recorded after a single combined application of a laboratory prototype based on A. papavericola 1.39-8 and sublethal doses of chemical herbicides based on the active ingredients metsulfuron-methyl and metribuzin. Mortality of test plants and losses in growth and biomass reached 99%.

Bacillus strains have long been widely and successfully used as the polyfunctional biologics’ basis in various systems for crops cultivation and protection. The research goal was to evaluate application effect from experimental prototypes of multirecycled polyfunctional biologics based on Bacillus subtilis I-5/12–23 together with compost in potato organic farming. A significant stimulation of potato plants Udacha variety growth and development up to the flowering phase was observed regardless of the growing season hydrothermal conditions. The stimulation was by the additive effect of joint biologics and compost use in proportion to its dose. The multirecycled substrate-associated and liquid polyfunctional biologics prototypes together with compost almost doubled the potato tubers biological yield compared to the control regardless the growing season conditions. In the flowering phase, the biological efficacy with respect to the potato fungal diseases incidence and development was 90% under optimal hydrothermal conditions and up to 75% under drought conditions. At the vegetation end the efficacy in the potato fungal diseases development reached 70% (compost efficiency itself more than 45%) regardless of the vegetation period conditions. Four-year scientific and producing approbation of the technological application rules for the biologics’ prototypes based on B. subtilis I5-12/23 and compost developed for the North-West region’s various weather and climatic conditions showed their high efficacy in protection the organic potato. Disease incidence on plants decreased about 80%, on tubers about 50%, their quality improved, and the marketable products yield increase at 9 t ha^− 1 (3 t ha^− 1, on average). The application’s technological rules optimizing for various weather and climatic conditions is carried out by changing the consumption norms of protection means in proportion to the limiting factors. Multirecycled polyfunctional biologics prototypes combining the properties of biopesticides, biofertilizers and inoculants can be used to ensure stable organic potato production.

Contemporary polyfunctional biologics using contributes to the soil suppressiveness increasing, improves the agroecosystems phytosanitary conditions and yields increases. The research goal was to biologically justify the new multirecycled biologic’s prototype based on Trichoderma asperellum T-36 in protecting spring soft wheat from diseases and increasing soil suppressiveness in West Siberia. The tasks were solved on the new multirecycled substrate-associated granular polyfunctional biologic (MSAPB, G) prototype developing; 2 years field trials data evaluating and statistically processing on phytoregulatory activity and field efficacy of prototype in spring soft wheat cultivation; total and induced soil suppressive activity estimating on natural and artificial infection backgrounds with T. asperellum T-36 involving. In 2 series field trials the prototype demonstrated phytoregulatory activity: biometric indices of wheat plants development under its influence reliably (p ≤ 0.05) 1.4 times exceeded the control ones. Biological efficacy against soil pathogens was 33–56, 41–59 %; in the development of leaf-stem infections 25–50, 30–98 % for template reference – Sternyphage, WP (wettable powder) and for MSAPB, G prototype respectively. From tube emergence to milk ripeness, the highest soil activity in rhizosphere under the prototype influence was reliably (p ≤ 0.01) 2 times higher than the control one. High total soil suppressiveness, as well as forming and strengthening of induced suppressiveness by protective biologics application in all phases of wheat plants development were shown. Successions were revealed in wheat holobiont development from 0 day up to vegetation end, caused by the absence of significant similarity in rhizosphere microbiota complexes in dynamics.

White button mushrooms yield instability in artificial cultivation, often caused by crop diseases. The main disease is wet bubble disease. The appearance of its causative agent, M. perniciosa, may lead to total yield loss. The microbiocontrol of M. perniciosa is focused on casing soil antagonist use. Since no industrial producer strains of polyfunctional biologics have been used in previous studies, our research goal was to characterize the effect of B. subtilis B-10 and M-22 on a mycopathogen and reveal its control possibilities. The reason for B. subtilis B-10 and M-22 use in mycopathogen control has been revealed by interactions between producer strains and the studying of M. perniciosa. The suppression of M. perniciosa development by producer strains was established, indicating a prolonged B-10 and M-22 effect on the mycopathogen. High biological efficacy in both strains at the early stages of mycopathogen development upon introducing them into the wells and spraying was shown: B-10—50.9–99.6% and M-22—57.5–99.2%, respectively (p ≤ 0.05). Significant differences between producer strains were not revealed, although during the first day of exposure to developed M. perniciosa colonies, M-22 showed greater activity. The high efficiency of preventive treatment when producer strains completely suppressed mycoparasite development permits us to recommend them both for introducing when preparing casing for M. perniciosa control.

Microbiocontrol of Mycogone perniciosa is focused on casing soil antagonists use. Since no industrial producer strains of polyfunctional biologics were used in previous studies, research goal was to characterize Bacillus subtilis B-10 and M-22 effect on mycopathogen and reveal its control possibilities. Interactions between producer strains and M. perniciosa were evaluated using well method and spraying. Mycoparasite colony area and its lysis zone were determined. Biological efficacy was characterized by lysis zone proportion in total area occupied by the micromycete mycelium. Statistical processing included W-test, ANOVA, means (M) and standard errors (±SEM) calculation. The significance was assessed by t-test. M. perniciosa development suppressing by producer strains was established, indicates a prolonged B-10 and M-22 effect on mycopathogen. High biological efficacy of both strains at the early stages of mycopathogen development by introducing into the wells and spraying was shown: B-10 – 50.9–99.6 % and M-22 – 57.5–99.2 % respectively (p ≤ 0.05). Significant differences between producer strains were not revealed, although during the first exposure day to developed M. perniciosa colonies M-22 has shown greater activity. Preventive treatment high efficiency when producer strains completely suppressed mycoparasite development, permit recommending them both to introduce when preparing casing for M. perniciosa control.

To increase the organic potato yield, it is necessary to provide the crop with sufficient nutrients and effective means of biocontrol the diseases. The research goal was to characterize the biorationals’ efficacy to achieve competitive organic potatoes’ yield under various weather conditions. A 4-year trial was carried out in the Leningrad region using Udacha variety potatoes. The tests used liquid forms of new polyfunctional biologicals Kartofin based on highly active Bacillus subtilis I-5-12/23 and organic fertilizer BIAGUM obtained from poultry manure by aerobic fermentation in a closed biofermenter. Significant stimulation in plant growth and development to the flowering phase regardless of the hydrothermal conditions of the growing season was noted. The stimulating effect was determined by the combined use of biorationals pro rata to BIAGUM dose. Kartofin biologicals and BIAGUM almost doubled the potato tubers’ yield compared to the control, regardless of the growing season conditions. At the flowering phase, the biological efficacy in potato fungal diseases incidence and development was near 90% under optimal and 50–75% under drought hydrothermal conditions. At the end of vegetation, the efficiency in fungal diseases incidence and development made up 45–65% under optimal and 45–70% under dry conditions. BIAGUM effectiveness in reducing disease development reached 45–50% regardless of growing season conditions.