Enhancing crop resilience by harnessing the synergistic effects of biostimulants against abiotic stress

Extending the Shelf Life of Strawberries: Physicochemical and Antibacterial Effects of Carboxymethyl Cellulose and Gelatin Coatings With Lemon Essential Oil

Edible coatings are a thin layer of substances that are put on the surface of food. This work was designed to investigate strawberry coating prepared of carboxymethyl cellulose (CMC), gelatin (G) enriched with lemon essential oil (LEO) in various concentrations (0.5%, 1.5%, 3%), on the antimicrobial characteristics, shelf life, physicochemical, and sensory properties of strawberries preserved for 16 days at 4°C ± 1°C and an RH of 85% ± 5%. It was found that adding LEO to the CMC + G coating inhibited yeast and mold growth as well as decreased weight loss. The total flavonoid (TF), total phenol content (TPC), ascorbic acid, and antioxidant activity (AOA) all decreased slowly. Furthermore, the CMC + G + LEO combination reduced fruit deterioration due to respiration-related cell wall degradation and delayed titratable acidity (TA); pH changes, as well as losses of the fruit's total soluble solid (SS), were decreased. Likewise, the simultaneous use of CMC, G, and LEO in the sensory assessment (texture, flavor, appearance, and over all acceptance) improved aroma and appearance in the sensory assessment of the current research employing CMC + G + LEO 3%. It also proved to be efficient in reducing firmness loss, total flavonoids, ascorbic acid, TPC, and AOA in strawberry fruits compared with the uncoated.

Advancing medicinal plant agriculture: integrating technology and precision agriculture for sustainability

To strengthen the agriculture sector, it is crucial to combine the efforts of industrialization (field mechanization and fertilizer production), technology (genome editing and manipulation), and the information sector (for the application of current technologies in precision agriculture). The challenge of modern sustainable agriculture is increasing agricultural output while using the least amount of resources and capital expenditure possible and considering the variables contributing to environmental damage. Different environmental factors adversely affect medicinal plant populations, leading to the extinction of these valuable medicinal species. These difficulties drew the attention of the international scientific community to farm sustainability and energy efficiency studies that put forth the idea of precision agriculture (site-specific crop management) in medicinal plants. It is a systems-based method that monitors and responds to changes in intra- and inter-field conditions for environmentally friendly and optimum crop output. Farming systems have significantly benefited from the visualization and morphological analysis of agricultural areas (both open fields and greenhouse experiments) using remote sensing technology, geographic information systems (GIS), crop scouting, variable rate technology (VRT), and Global Positioning System (GPS). These technologies form the backbone of the fourth agricultural technological revolution, Agriculture 4.0. This review concisely summarizes these innovative technologies' current use and potential future advancements in medicinal plants. The review is intended for researchers, professionals in medicinal plant cultivation, herbal medicine research, crop science, and related fields.

Nanoparticles as tools for enhancing plant resistance to biotic stress in the context of climate change

In the face of climate change, agriculture is increasingly challenged by shifting dynamics of biotic stresses, including the intensified spread of pests and pathogens. Traditional control methods, often reliant on chemical pesticides, are associated with environmental degradation and potential health risks. Nanoparticles (NPs) present a promising, sustainable alternative for enhancing plant resistance to biotic stresses, potentially revolutionizing agricultural practices. This mini-review explores the mechanisms through which NP-based formulations (such as metal-based NPs, chitosan, and silica) induce plant responses and bolster defences against pathogens and pests. By enhancing plant resilience without the environmental downsides of conventional pesticides, NPs could support a more sustainable approach to crop protection. This review also highlights the potential risks in expanding the use of NPs in agriculture, urging more studies to explore these technologies as a sustainable approach to managing crops in a changing climate.

Characterization and Rheological Properties of a New Exopolysaccharide Overproduced by Rhizobium sp. L01

The exopolysaccharides produced by rhizobia play an important role in their biotechnological and bioremediation properties. The characteristics and properties of an exopolysaccharide produced by Rhizobium sp. L01 were investigated. Strain Rhizobium sp. L01 was identified as Rhizobium tropici and produced a high yield of exopolysaccharides (REPS-L01), reaching 22.8 g/L after 63 h of fermentation in a 5 L bioreactor with glucose as the carbon source. REPS-L01 was composed of glucose and galactose in a ratio of 2.95:1, carrying pyruvate, acetate, and succinate groups. REPS-L01 had good shear-thinning properties in aqueous solutions at various concentrations and revealed typical non-crosslinked polymer properties. REPS-L01 revealed thermal stability up to 275 °C. REPS-L01 had the potential to be thicker, being suitable for use under conditions ranging from 4 to 60 °C, pH between 2 and 12, and salt concentrations up to 20,000 mg/L. REPS-L01 showed strong emulsifying activity, particularly with n-hexane; even at concentrations as low as 0.25 wt%, the emulsification index could reach more than 50%. Even more impressively, stable n-hexane emulsion gel was formed with 2 wt% REPS-L01 solution. Rheological studies showed that the solid-like emulsion gel had a high storage modulus, and the SEM studies of the emulsion gel indicated that n-hexane could fill the pores of REPS-L01.

Enhancing the growth and essential oil components of Lavandula latifolia using Malva parviflora extract and humic acid as biostimulants in a field experiment

Natural extracts as biostimulants have the potential to enhance the productivity and growth of many medicinal and aromatic plants. This study aimed to enhance the growth, and essential oil (EO) content, as well as composition of Lavandula latifolia Medik. by using Malva parviflora L. extract (ME) as a biostimulant in combination with humic acid (HA) in a field experiment in two successive seasons of 2022 and 2023. The phenolic, flavonoid and water-soluble vitamins of the ME were analyzed using an HPLC. The protein amino acids of the ME were identified by an amino acid analyzer. The prepared concentrations of HA (0, 1, 2, and 4 g/L) were applied to the soil. While, they for ME (0, 2, 4, and 6 g/L) were added as a foliar spray. The EO compositions collected from the leaves of the treated L. latifolia plants were subjected to the hydro-distillation method and analyzed using GC-MS. The most prevalent vitamins found in ME were vitamin B12, vitamin C, and folic acid. Besides, several phenolic compounds were found in ME, such as catechol, cinnamic acid and syringic acid, while flavonoid chemicals, such as luteolin and quercetin. Also, alanine, ammonia, aspartic acid, glutamic acid, glycine, and tyrosine were the ME's most prominent nitrogenous and amino acid components. The most effective treatments of HA and ME on the plant height, the number of branches/plant, and plant fresh weight were 4 + 6 g/L and 4 + 2 g/L for leaf area and chlorophyll content, it was 4 + 4 g/L; and for EO percentage were 4 + 0 g/L, 2 + 0 g/L, and 4 + 4 g/L, compared to the control treatment for each characteristic. The main EO compounds eucalyptol, camphor, α-pinene, β-pinene, Δ-elemene, germacrene D-4-ol, isoborneol, β-caryophyllene oxide, and tau.-cadinol identified in the leaves were found in the range of 28.74-46.19%, 15.34-30.49%, 3.39-7.16%, 0-5.08%, 0-5.18%, 0-3.20%, 0-3.31% and 0-3.40%, respectively. It can be concluded that a combination treatment of HA and ME as natural biostimulant compounds at 4 + 4 g/L could be recommended for good plant growth, and EO quantity of L. latifolia plants.

GLYCINE betaine and seaweed-based biostimulants improved leaf water status and enhanced photosynthetic activity in sweet cherry trees

Sweet cherry is a high-value crop, and strategies to enhance production and sustainability are at the forefront of research linked to this crop. The improvement of plant status is key to achieving optimum yield. Biostimulants, such as glycine betaine (GB) or seaweed-based biostimulants [e.g., Ecklonia maxima (EM)], can represent a sustainable approach to improving plant conditions, even under adverse environmental circumstances. Despite their potential, few studies have focused on the effects of GB or EM exogenous application on sweet cherry tree physiology. To address this lack of research, a study was conducted in a Portuguese sweet cherry commercial orchard, using Lapins and Early Bigi cultivars. Trees were treated with products based on GB and EM at two different concentrations [GB 0.25% (v/v) and GB 0.40% (v/v); EM 0.30% (v/v) and EM 0.15% (v/v)], a combination of the lowest concentrations of both biostimulants (Mix -GB 0.25% and EM 0.15%), and a control group (C) treated with water. Applications were performed over three consecutive years (2019, 2020, and 2021) at three different phenological stages, according to the BBCH scale: 77, 81, and 86 BBCH. Results showed, in general, that the application of biostimulants led to improvements in water status as well as significantly lower values of electrolyte leakage and thiobarbituric acid reactive substances compared to C samples. Additionally, biostimulants reduced pigment loss in the leaves and enhanced their biosynthesis. The Chlorophylla/Chlorophyllb ratio, ranging from 2 to 4, indicated a greater capacity for light absorption and lower stress levels in treated leaves. Soluble sugar and starch content decreased during fruit development in both cultivars and years; however, biostimulants increased these contents, with increments of approximately 15% to 30% in leaves treated with EM. Soluble protein content also showed the same pattern for treated leaves. Biostimulants, especially EM, demonstrated a significant positive effect (p ≤ 0.001) on total phenolic content, with increases of approximately 25% to 50% in treated leaves. In conclusion, the application of biostimulants, especially algae-based, significantly improved tree performance by enhancing physiological parameters and stress resilience and could represent a novel approach in fruit production systems.

Enhancing Maize Stress Tolerance and Productivity through Synergistic Application of Bacillus velezensis A6 and Lamiales Plant Extract, Biostimulants Suitable for Organic Farming

Maize, a globally significant cereal, is increasingly cultivated under challenging environmental conditions, necessitating innovations in sustainable agriculture. This study evaluates the synergistic effects of a novel technique combining a Bacillus velezensis A6 strain with a plant extract from the Lamiales order on maize growth and stress resilience. Employing a pilot field trial, this study was conducted on the "La Añoreta" experimental farm of the ECONATUR group, where various biostimulant treatments, including bacterial and plant extract applications, were tested against a control group. The treatments were applied during key vegetative growth stages (V10-Tenth-Leaf, VT-Tassel, R1-Silking) and monitored for effects on plant height, biomass, and fumonisin content. The results suggest that the combined treatment of Bacillus velezensis A6 and the plant extract increases maize height (32.87%) and yield (62.93%) and also reduces fumonisin concentrations, improving its resistance to stress, compared to the control and other treatments. This study highlights the potential of microbial and botanical biostimulants and its novel combination for improving crop productivity and sustainability, suggesting that such synergistic combinations could play a crucial role in enhancing agricultural resilience to environmental stresses.

Evaluation of the Biostimulant Activity and Verticillium Wilt Protection of an Onion Extract in Olive Crops (Olea europaea)

The olive tree is crucial to the Mediterranean agricultural economy but faces significant threats from climate change and soil-borne pathogens like Verticillium dahliae. This study assesses the dual role of an onion extract formulation, rich in organosulfur compounds, as both biostimulant and antifungal agent. Research was conducted across three settings: a controlled climatic chamber with non-stressed olive trees; an experimental farm with olive trees under abiotic stress; and two commercial olive orchards affected by V. dahliae. Results showed that in the climatic chamber, onion extract significantly reduced MDA levels in olive leaves, with a more pronounced reduction observed when the extract was applied by irrigation compared to foliar spray. The treatment also increased root length by up to 37.1% compared to controls. In field trials, irrigation with onion extract increased the number of new shoots by 148% and the length of shoots by 53.5%. In commercial orchards, treated trees exhibited reduced MDA levels, lower V. dahliae density, and a 26.7% increase in fruit fat content. These findings suggest that the onion extract effectively reduces oxidative stress and pathogen colonization, while enhancing plant development and fruit fat content. This supports the use of the onion extract formulation as a promising, sustainable alternative to chemical treatments for improving olive crop resilience.