This study showed the eliciting effect of aqueous extracts from Ascophyllum nodosum on the development of Eruca sativa microgreens in a quartz-based substrate. There is no information in the literature on the impact of its use on the quality, bioactive compound content, and nutritional value of arugula microgreens. Assays that have been made include the following: total phenolic content (TPC), total flavonoid content (TFV), enzymes such as phenylalanine ammonia (PAL) and polyphenol oxidase (PPO), and enzymes involved in the scavenging of reactive oxygen species such as catalase (CAT) and superoxide dismutase (SOD). The antioxidant activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) was also evaluated. The total phenolic content of arugula microgreens increased significantly after an application of aqueous extracts of A. nodosum to the substrate. The greatest increase in flavonoid content (89%) and antioxidant activity against DPPH (82%) was observed at a concentration of 2.5%. The highest increase in activity of CAT (68.2%), SOD (25%), PAL (13-fold), and PPO (84.2%) was observed with the application of 5% extract. In conclusion, the use of Ascophyllum nodosum algae affects TPC and TFV, antioxidant activity, PAL, PPO, SOD, and CAT in the microgreens studied. By prioritising organic and environmentally friendly extracts, growers can contribute to a more sustainable and healthier food system, especially in the case of the production of Eruca sativa microgreens.

This paper describes the influence of Ascophyllum nodosum algae on the seeds, microgreens, yield, and yield components of oat Avena sativa cv. Bingo. This article includes the results from three experiments. In one of the experiments, the oat seeds were soaked in a solution of demineralized water with dried comminuted and homogenized algae. For the FT–Raman spectra measurements, a spectrometer with an Nd:YAG laser, with a germanium detector, was used. The results obtained show that an excessively low as well as an excessively high alga concentration did not have an influence on the change in oat composition. Other algae concentrations that were used in these experiments caused significant chemical changes in the oat seeds. For the FT–Raman data, separation of the control from all the oat grains treated with different algae concentrations was possible. The aim of the pot experiment was to determine the effect of the application of algae (in different doses) on the A. sativa green mass of young plants (microgreens). The certified oat seeds, after being soaked in a solution with algae, were planted in the ground. For the chemometric analysis of the oat samples, a Fourier-transform infrared (FTIR) spectrometer device was used. The data were recorded with a viewing diamond with an attenuated total reflection (ATR) crystal plate. The FTIR spectra showed that soaking in an algae suspension affected the germination, general metabolism, and chemical composition of the oats. The use of algae did not change the lipid content of the plant. The three-year field experiment was established by introducing two factors: A. nodosum application (A) and a pre-sowing stimulation with a low-frequency magnetic field (S). The influence of experimental factors on the oat yield and its structure (yield structure components and yield components) was investigated. The beneficial effect of algae on oat yield was demonstrated by improved parameters such as the number and weight of the grains; however, under field conditions, the pre-sowing magnetic field stimulation of seeds did not have a beneficial effect. Various weather conditions also had a great influence on the yield. This study also considered the role of A. nodosum as a biostimulant in plants, and this showed potential under less favorable conditions.

Soil salinity stress is a serious problem in plant cultivation. The effect of this stress is to disrupt the photosynthetic process, which can cause growth restrictions and a decrease in plant productivity. The use of biostimulants can be one of the stress mitigation strategies in plant cultivation. Biostimulants increase the tolerance of plants to abiotic stresses, thus mitigating their adverse effects. In the present study, based on a pot experiment, the effect of foliar application of biostimulants differentiated in terms of chemical composition (Bombardino (B1), Quantis^® (B2), Biofol Plex (B3) and Megafol (B4)) on the physiological properties of Chinese silver grass (Miscanthus sinensis (Anderss.)) plants growing under salt stress conditions was determined. Salt stress was induced by soil application of NaCl at concentrations of 200 and 400 mM. The application of salt solutions was followed by spraying Miscanthus plants with biostimulants using a hand-held sprayer. Physiological investigations (chlorophyll content, chlorophyll fluorescence and gas exchange) have been carried out twice: on the 1st (Term I) and 7th (Term II) day after spraying with biostimulants. It was shown that salt stress causes a decrease in the values of most of the physiological indicators tested (except Ci). On both measurement dates, the application of biostimulants, especially B2, caused an improvement in the values of the physiological indices studied, both for plants growing under optimal conditions and under salt stress. Term II showed an upward trend in most of the analyzed parameters compared to Term I, indicating plant acclimatization to stress conditions. Conducted studies have shown that using biostimulants contributes to the alleviation of the effects of soil salinity stress. The implementation of these practices can contribute to the advancement of sustainable farming.

Field studies were conducted from 2016 to 2019 (south-eastern Poland; 49°58′40.6″ N 22°33′11.3″ E) with the aim to identify the chemical composition of winter wheat grain upon foliar application of biostimulants, of which PlanTonic BIO (containing nettle and willow extracts) showed antifungal activity. The main chemical compositions and their spatial distribution in wheat grain were characterized by Raman spectroscopy technique. It was established that applied biostimulants and hydro-thermal conditions changed the chemical composition of the grain during all the studied years. A similar chemical composition of the grain was achieved in plants treated with synthetic preparations, including both intensive and extensive variants. The second group, in terms of an increase in fatty acid content, consists of grains of plants treated with biostimulants PlanTonic BIO, PlanTonic BIO + Natural Crop and PlanTonic BIO + Biofol Plex. The future of using biostimulants in crop production, including those containing salicylic acid and nettle extracts, appears to be a promising alternative to synthetic crop protection products.

Algae extracts may be a promising alternative to harmful chemicals and pesticides used commercially in the cultivation of plants with higher nutritional and health-promoting values. The cultivation of barley microgreens (Hordeum vulgare L.) was facilitated by the use of aqueous extracts from Fucus vesiculosus algae, which served as a biostimulant. Seeds for experiments were produced in accordance with EU standards, certified as organic and used to grow plants in a controlled pot experiment. A qualitative analysis of the extract, which was used to irrigate the plants, was also performed in this study, as well as stimulating properties by activating the system protecting against oxidative stress. Total phenolic content (TPC), total flavonoid content (TFV) and enzymes involved in their formation such as phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO), as well as enzymes involved in the removal of reactive oxygen species such as catalase (CAT) and superoxide dismutase (SOD), were determined in the obtained microgreen samples. Antioxidant activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) was also evaluated. A noticeable increase in SOD content and antioxidant activity against DPPH was observed in barley microgreen samples after extract treatment. These results suggest that the use of extracts of this beneficial alga can enhance the antioxidant activity of the barley microgreens.

Ecdysteroids (ECs) are steroid hormones originally found in the animal kingdom where they function as insect molting hormones. Interestingly, a relatively high number of these substances can also be formed in plant cells. Moreover, ECs have certain regulatory effects on plant physiology, but their role in plants still requires further study. One of the main aims of the present study was to verify a hypothesis that fenarimol, an inhibitor of the biosynthesis of ECs in the animal kingdom, also affects the content of endogenous ECs in plants using winter wheat Triticum aestivum L. as a model plant. The levels of endogenous ECs in winter wheat, including the estimation of their changes during a course of different temperature treatments, have been determined using a sensitive analytical method based on UHPLC-MS/MS. Under our experimental conditions, four substances of EC character were detected in the tissue of interest in amounts ranging from less than 1 to over 200 pg·g⁻¹ FW: 20-hydroxyecdysone, polypodine B, turkesterone, and isovitexirone. Among them, turkesterone was observed to be the most abundant EC and accumulated mainly in the crowns and leaves of wheat. Importantly, the level of ECs was observed to be dependent on the age of the plants, as well as on growth conditions (especially temperature). Fenarimol, an inhibitor of a cytochrome P450 monooxygenase, was shown to significantly decrease the level of naturally occurring ECs in experimental plants, which may indicate its potential use in studies related to the biosynthesis and physiological function of these substances in plants.