Lavender is among the medicinal and aromatic plants with high economic value in the food, pharmaceutical, cosmetic and aromatherapeutic industries, and in its composition has numerous compounds, such as tannins, anthocyanins, minerals, saponins, flavonoids, polyphenols, essential oil and others. The qualitative and quantitative characteristics of lavender are best highlighted by extraction techniques such as hydrodistillation, steam distillation and supercritical CO₂ extraction. In the water distillation extraction method, the plants are soaked in water until boiling and steam is released, carrying the essential oils with it, which are then separated via cooling. Steam distillation is one of the most common methods used to extract essential oils from medicinal and aromatic plants. Unlike hydrodistillation, where the water is stored directly in a tank, in this method, the steam is transported into the tank from the outside and the oils are released from the plant components when the steam penetrates the structures that contain it. Essential oils contain essential compounds that have antioxidant, antimicrobial, anti-fungal, etc., properties. All the component parts of lavender contain essential oils, which are distributed as follows: in leaves at about 0.4%, in stems at about 0.2%, and in inflorescences at about 2–4.5%.

Enhancing the efficacy of biofertilizers and biopesticides for horticultural applications presents numerous challenges, given the need to balance effectiveness with environmental and economic factors. Achieving these goals requires rigorous research into advanced technologies and formulations capable of effectively replacing or complementing traditional chemical inputs, without compromising crop yield or quality. The present study aimed to develop a versatile and yet accessible hybrid percolation–sonication system and method, designed to optimize polyphenol extraction from nettle and sage plants. The resulting extracts were combined and applied on organic tomato crops, to evaluate their biofertilizer and biopesticide effectiveness, in comparison to conventional chemical inputs. Operating the equipment in a hybrid percolation–sonication system led to a 36% increase in polyphenols extraction for nettle and a 29% increase from sage. Regarding the effect on tomatoes, data showed that plants treated with biofertilizer extracts were over 42.88% more productive than control samples and 17.67% more productive than tomatoes treated with chemical fertilizers. Tomato plants treated with biofertilizers grew approximately 10% taller and developed stems that were 5% thicker compared to those treated with chemical fertilizers.

The present research aimed to improve the extraction efficiency of polyphenolic compounds from nettle and sage, using an improved hybrid ultrasound—percolation extraction method. A factorial experimental design was employed to systematically evaluate the influence of key extraction parameters: pressure (5, 6, and 7 bar), extraction time (60, 90, and 120 min), and ultrasound power (80, 100, and 120 W) on the total polyphenol content (TPC) of the resulting extracts. The obtained extracts were comprehensively analyzed in terms of total polyphenol concentration, micro- and macronutrient content, and antioxidant activity. Based on the results, optimal extraction conditions were determined and subsequently used to formulate a biostimulant solution derived from nettle and sage. To validate the agronomic efficacy of the formulated biostimulant, greenhouse trials were conducted on tomato (Solanum lycopersicum) and pepper (Capsicum annuum) plants. The impact of the treatment was assessed by monitoring vegetative growth (total dry mass), chlorophyll content, and crop productivity. The central hypothesis is that systematic variation of the hybrid ultrasound-assisted percolation process parameters will reveal a range capable of significantly improving the polyphenol yield and antioxidant activity of nettle and sage extracts. We further used these improved extracts to increase certain health indicators and overall productivity in tomato and pepper plants. At the end of the growing period, the treated plants showed an increase in dry mass of 22% for tomatoes and 20% for peppers relative to controls samples. Furthermore, productivity showed a substantial increase, rising by 38.6% for tomatoes and 53% for peppers. Chlorophyll content also increased by up to 20% in tomatoes and up to 22% in peppers, showing better plant health.

This article presents the results of experimental research on the extraction of polyphenols from nettle, lavender, and sage using the percolation method. This technique is recognized for its efficiency in extracting bioactive compounds from plants. Polyphenols are a group of natural chemical compounds characterized by the presence of multiple phenolic groups in their molecular structure. They are predominantly found in plants and are recognized in various industries, including agriculture, for their antioxidant, antimicrobial, and antifungal properties. The antioxidant capacity of the extracts from nettle, lavender, and sage refers to the ability of these extracts to neutralize free radicals. The concentrations of polyphenols in the obtained extracts were measured using the Folin-Ciocalteu spectrophotometric method. The impact of pressure on total polyphenol content varied by plant species. Sage showed increased polyphenol content at higher pressures, indicating more efficient extraction with the proposed technology.