Results – Stage 2 – 2025

Executive summary of activities carried out

In this stage of the project, polyphenolic extracts were obtained and characterized from perennial plant species with bioprotective potential: stems and leaves of Reynoutria sachalinensis (Rel, Re), roots of Sophora flavescens (S), and roots of Rheum rhabarbarum (Ru18 and Ru19). The aim was to obtain stable formulations with optimal polyphenol content and high antioxidant capacity, suitable for integration into microemulsions for the control of harmful organisms in agriculture. Evaluation of extract stability under low and high temperatures confirmed the resilience of the bioactive compounds, supporting their application and storage under various conditions.

Based on the selected extracts, microemulsions were formulated in combination with rapeseed oil at concentrations of 1% (R1), 3% (R3), and 8% (R8). Characterization of these microemulsions revealed significant differences in polyphenol content and antioxidant capacity, depending on the plant type and oil concentration. The best results were obtained from microemulsions based on R. sachalinensis leaves, particularly Re-R8, which showed the highest polyphenol content (5.105 mg gallic acid/ml) and antioxidant capacity (130.663 mM Trolox/ml). The Re-R1 and Re-R3 formulations also demonstrated high values, confirming the potential of this species for developing effective bioproducts.

Biological testing was carried out in protected environments on pepper and cucumber crops, evaluating the efficacy of Sophora flavescens extracts against aphids (Aphis gossypii) and the two-spotted spider mite (Tetranychus urticae). Application of the extracts at 1.5 % and 2.0 %, alongside the standard (rapeseed oil 1.0 %) and untreated control, resulted in a rapid and significant reduction in pest density within the first 24 hours: 72–80 % for aphids and 75–82 % for mites. The 2.0 % dose consistently showed higher efficacy, though effectiveness gradually declined by day 7, indicating a predominantly contact-based effect and the need for optimization of formulation and treatment frequency. In all cases, treatments were applied above the economic threshold, confirming the extracts’ capacity to limit pest population growth.

In conclusion, the obtained extracts and microemulsions show potential for use as natural insecticides and fungicides, reducing dependence on chemical substances and supporting the development of an ecological and sustainable agricultural sector. The results justify continued research aimed at optimizing formulations, increasing biological stability, and evaluating their field performance for integrated crop protection in horticulture.

A product:

  • Rheum rhabarbarum extract with antioxidant and antifungal properties, authors: Maria-Loredana Soran, Ildiko Lung, Ocsana Opriş, Adina Stegarescu, Svetlana Jalbă (reg. no. 2688/25.11.2025).

A preparation method for microemulsions:

  • Method for obtaining microemulsions based on perennial plant extracts with synergistic effect, authors: Maria-Loredana Soran, Ildiko Lung, Ocsana Opriş, Adina Stegarescu, Svetlana Jalbă (nr. înreg. 2687/25.11.2025).

Article submitted for publication: 1      

  • I. Lung, S. Jalbă, O. Opriș, A. Stegarescu, L.C. Văcar, D. Podar, V. Todiraș, M.L. Soran, Antifungal activity of optimized Reynoutria sachalinensis extracts against Fusarium oxysporum f. sp. Lycopersici. Acta Scientiarum – Agromony

Manuscript under preparation: 1

  • S. Jalbă, I. Lung, M.L. Soran, A. Stegarescu, L.C. Văcar, D. Podar, V. Todiraș, O. Opriș, Evaluation of Rheum rhabarbarum extract-based formulations for disease control in cucurbit crops.

Participation in international conferences: 12

  • M.L. Soran, I. Lung, O. Opriș, S. Jalbă, A. Stegarescu, S. Pintea, V. Todiraș, Antifungal effects of Rheum rhabarbarum extracts obtained by sonication, 15th International Conference – Processes in Isotopes and Molecules, PIM 2025, 16-19 septembrie 2025, Cluj-Napoca, România.
  • S. Jalbă, T. Erhan, I. Lung, V. Todiraș, M.L. Soran, O. Opriş, A. Stegarescu, Optimisation of sonication method for bioactive compounds extraction from diferent plants, XVI International Agriculture Symposium “AGROSYM 2025” 2-5 octombrie 2025, Bosnia și Herzegovina.
  • T. Erhan, S. Jalbă, I. Lung, V. Todiraș, M.L. Soran, O. Opriş, A. Stegarescu, The optimization of polyphenols extraction method from Rheum rhabarbarum for the extract using in agriculture, XVI International Agriculture Symposium “AGROSYM 2025” 2-5 October 2025, Bosnia and Herzegovina.
  • V. Todiraș, M.L. Soran, S. Jalbă, T. Erhan, I. Lung, O. Opriş, A. Stegarescu, Studies on the optimization of Sophora flavescens extract as a natural insecticide in greenhouses, Agriculture&Food 2025, 13th International Conference, 11-14 august 2025, Burgas, Bulgaria.
  • T. Erhan, S. Jalbă, I. Lung, V. Todiraș, M.L. Soran, O. Opriş, A. Stegarescu, Optimization of Reynoutria sachalinensis extracts for grapevines powdery mildew management, Agriculture&Food 2025, 13th International Conference, 11-14 august 2025, Burgas, Bulgaria.
  • S. Jalbă, V. Todiraș, T. Erhan, I. Lung, O. Opriş, A. Stegarescu, M.L. Soran, Research on the optimization of Reynoutria sachalinensis extracts for organic plant protection, Agriculture&Food 2025, 13th International Conference, 11-14 august 2025, Burgas, Bulgaria.
  • A. Stegarescu, M.L. Soran, O. Opriș, I. Lung, S. Jalba, V. Todiraş, S. Pintea, C.L. Văcar, Preparation and characterization of polyphenolic extracts as possible natural insecticide, International Experts Summit on Materials Science and Nanotechnology, 16-18 iunie, 2025, Barcelona, Spania.
  • V. Todiraș, Development of online spatio-temporal risk prediction model for downy mildew (Plasmopara viticola) in grapevine, 5th Edition of the Global Conference on Agriculture and Horticulture (Agri 2025), 08-10 septembrie, 2025, Valencia, Spania.
  • V. Todiraș, S. Jalbă, T. Erhan, I. Lung, M.-L. Soran, O. Opriş, A. Stegarescu, Evaluation of the synergistic effect of plant extracts in microemulsions for combating harmful organisms OF agricultural crops, 6th Global Summit on Agriculture & Organic Farming, 23-24 octombrie, 2025, Paris, Franţa.
  • S. Jalbă, V. Todiraș, T. Erhan, I. Lung, M.L. Soran, O. Opriş, A. Stegarescu, Study of the stability of polyphenols from Reynoutria sachalinensis leaves extract with potential use in organic agriculture, 6th Global Summit on Agriculture & Organic Farming, 23-24 octombrie, 2025, Paris, Franţa.
  • T. Tretiacov, V. Todiraș, A. Gusan, Automatic monitoring system for phytosanitary risk assessment in apple orchards. International Symposium „Advanced biotechnologies- achievements and prospects, 2025”, septembrie 17-19, 2025, Chișinău, Moldova.
  • V. Todiraș, Optimization of Pesticide Components and Application Strategies through Multicriteria Analysis. 5th International Conference on Plant Science and Agriculture Research (Plant Science Conference 2025), November 21-22, 2025 | London, UK.