(1) Background: Strawberry plants are strongly affected by heavy-metal-contaminated soils, which affects plant growth, yield and fruit quality. The aim of this work was to study the effects of a combination and individual application of silicon (Si) and humic acid (HA) on growth and development of Rubygem strawberries exposed to cadmium (Cd) in greenhouse conditions. (2) Methods: Morphological, physiological and biochemical parameters, including minerals in roots and leaves were determined. (3) Results: Cd stress in strawberry plants decreased plant fresh and dry weight; leaf stomatal conductance; leaf relative water content and chlorophyll content; number of leaves; leaf area; leaf N, P and K levels; and root P, N, Mg, K and Ca contents. Cd increased membrane permeability, leaf temperature, proline levels and lipid peroxidation. Si and HA individual applications to strawberries mitigated the negative effect of Cd stress on biochemical, physiological, morphological and minerals parameters by decreasing membrane permeability, leaf temperature, proline levels and lipid peroxidation. (4) Conclusions: Our findings highlighted that applications of Si, HA and Si + HA were effective in conferring Cd tolerance in strawberry plants by upregulating their many morphological, physiological and biochemical properties and reducing Cd stress.

Drought is a significant abiotic stress that adversely affects plant growth, development, and metabolic processes, posing a global threat to food security. In recent years, nanotechnology has emerged as a promising strategy to mitigate environmental challenges and has been tested on various plant species; however, its application to grapevines remains largely unexplored. This study aims to investigate the potential of silicon nanoparticles (SiO₂ NPs) to modulate morphological, physiological, and biochemical parameters in grapevine saplings (5 BB/Crimson Seedless, 41 B/Crimson Seedless, and 1103 P/Crimson Seedless) under drought stress conditions. Saplings were treated with foliar applications of different concentrations of SiO₂ NP solutions (0 (control), 1, 10, and 100 ppm) under well-irrigated (90–100% field capacity) and drought stress (40–50% field capacity) conditions. The results indicated that the application of SiO₂ NPs at 10 ppm concentration enhanced growth parameters (such as leaf area, leaf number, shoot fresh and dry weight, root fresh and dry weight) and chlorophyll content under both well-irrigated and drought conditions. Additionally, there was an improvement in leaf relative water content (RWC) and stomatal conductance, correlating with increased protein content. Under drought conditions, oxidative stress indicators, including drought index, leaf temperature, membrane injury index, hydrogen peroxide (H₂O₂) content, and malondialdehyde (MDA) levels, showed a significant decrease. Concurrently, proline content, total phenolic compounds, and activities of antioxidant enzymes (SOD, CAT, and APX), which increased under drought stress, were reduced in the presence of 10 ppm SiO₂ NPs, suggesting a mitigation of oxidative stress. To comprehensively evaluate the effects of SiO₂ NP concentrations, irrigation regimes, and rootstock/variety combinations, correlation analysis, principal component analysis (PCA), and hierarchical clustering heatmap analysis were performed. Collectively, the findings suggest that the observed drought-induced oxidative stress tolerance in grapevine saplings in the presence of 10 ppm SiO₂ NPs may result from the influence of antioxidant systems leading to a balanced redox potential. These results support the argument that SiO₂ NPs play a crucial role in enhancing drought tolerance, with implications for managing drought stress in other agricultural crops as well.

(1) Background: Raisins contain a wide range of hormones, minerals, vitamins, and antioxidant enzymes that may contribute to the health benefits of consumers. (2) Methods: The aim of this research was to compare the hormone, mineral, vitamin, and antioxidant capacities of Gök Üzüm (Vitis vinifera L.) raisins immersed in oak ash (OA) and potassium carbonate (PC) dipping solutions before drying. (3) Results: Abscisic acid (ABA) (5751.18–11,868.40 ng g⁻¹) and riboflavin (95.17–135.54 mg 100 g⁻¹) were the most abundant hormone and vitamin quantified in Gök Üzüm raisins. Glutathione S-transferase (540.07–744.85 EU gr berry⁻¹), 6-glucose phosphate dehydrogenase (214.50–317.43 EU gr berry⁻¹), and glucose-6-phosphate dehydrogenase (208.25–241.86 EU gr berry⁻¹) enzymes presented the highest antioxidant activity in the samples. Raisins obtained after drying by immersion in OA presented higher indol-3-acetic acid (IAA), ABA, salicylic acid (SA), cytokinins (CK), and zeatin contents; glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), glutathione S-transferase (GST), 6 glucose phosphate dehydrogenase (6GPD), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) enzymatic activity; vitamin B1, B2, B6, C, and A contents; and nitrogen (N), phosphorus (P), manganese (Mn), calcium (Ca), sulfur (S), potassium (K), iron (Fe), sodium (Na), and magnesium (Mg) levels compared to the grapes dried after PC applications. (4) Conclusions: Drying Gök Üzüm grapes after the application of OA dipping solution promotes a higher content of hormones, minerals, vitamins, and antioxidant enzymes compared to PC treatments. These results could help raisin producers to make decisions when using a dipping solution to dry grapes.