Benefits of nanotechnology in agriculture include reduced fertilizer loss, improved seed germination rate and increased crops quality and yield. The objective of this research was to evaluate the effects of zinc oxide nanoparticles (ZnO-NPs), at 1500 ppm, on tomato (Solanum lycopersicum L.) growth. ZnO-NPs were synthetized to produce either spherical or hexagonal morphologies. In this research, we also studied two application methods (foliar and drench) and nanoparticles’ (NPs) surface modification with maltodextrin. The results obtained indicate that ZnO-NP-treated tomato plants significantly increased plant height, stem diameter and plant organs (leaves, stem and root) dry weight compared to plants without NP treatment.

Nanotechnology has developed materials that can increase food production while reducing the use of conventional fertilizers. In this study, the effect of two forms of application (foliar and drench) as well as covering or non-covering of the surface of titanium dioxide nanoparticles (nTiO₂) with maltodextrin (MDX) at 1500 ppm was investigated on tomato plants. The results show that treatment of tomato with nTiO₂ increased yield (+21%), while covering the surface of the NPs resulted in a further yield increase (+27%). Similar trends were observed in the dry weight of vegetative plant parts. Fruit firmness (+33%) and total soluble solids (+36%) were enhanced by MDX-covered nTiO₂. Application of nTiO₂ resulted in enhanced SPAD index, photosynthesis rate, NO₃⁻, K, and Ca concentration in the petiole sap, whereas in the fruits there was an increase in P and K in MDX-covered nTiO₂. Considering the dilution effect due to the higher fruit yield, N, P, Mg, Cu, and B increased in plants treated with nTiO₂. Covering the surface with MDX resulted in an enhanced response to nTiO₂, as fruit yield and quality increased compared to plants treated with non-covered nTiO₂.

The use of zinc oxide nanoparticles (ZnO-NPs) is a promising strategy to enhance zinc availability and promote plant growth due to their physicochemical properties and biocompatibility. This study evaluated the effects of ZnO-NP morphology (spherical and hexagonal), maltodextrin (MD) surface coating, and a concentration range of 0–2000 mg L⁻¹ on growth and gas exchange in bell pepper seedlings. ZnO-NPs increased seedling height, especially at 750 and 1000 mg L⁻¹ for MD-coated spherical NPs and at 250 and 500 mg L⁻¹ for MD-coated hexagonal NPs. Spherical NPs also enhanced stem diameter, root length, and the dry weight of roots and stems. Leaf dry weight was highest with MD-coated spherical NPs, while hexagonal forms had milder effects. Dose–response analysis revealed that, with the exception of hexagonal MD-coated NPs, the total dry weight of seedlings stabilized at concentrations ranging 219.6 to 313.6 mg L⁻¹. Gas exchange parameters were significantly influenced by the evaluated factors. Uncoated hexagonal NPs at 1500 mg L⁻¹ increased the photosynthetic rate by 239%. MD coating improved performance, particularly in spherical NPs at 750 and 1000 mg L⁻¹. The transpiration rate rose with MD-coated hexagonal NPs at 500–2000 mg L⁻¹, and SPAD units increased with both morphologies. Overall, this study confirms that ZnO-NP morphology and surface coating play key roles in enhancing growth and physiological responses in bell pepper seedlings.

Salinity is a major abiotic constraint limiting strawberry (Fragaria × ananassa) productivity by disrupting water relations, nutrient uptake, and photosynthetic processes. Biopolymer-based biostimulants have emerged as a sustainable strategy to enhance crop performance under stress conditions. The objective of this study was to evaluate the effect of a chitosan–maltodextrin (CHTMD) formulation on growth, physiological response, and fruit quality in strawberry plants under saline conditions at the Universidad Autonoma Agraria Antonio Narro in Saltillo, Mexico. A randomized complete block design with a 2 × 4 factorial arrangement was established, including two salinity levels (0 and 45 mM NaCl) and four CHTMD concentrations (0, 250, 500, and 1000 mg L⁻¹). The application of CHTMD significantly mitigated the adverse effects of salinity and improved plant growth, biomass accumulation, gas exchange, yield, and fruit quality. Under saline conditions, 250 mg L⁻¹ increased total fresh weight by 148.5% compared with the saline control, while root length increased by up to 58.5% under non-saline conditions. Yield was enhanced by 87.3% and 71.4% with 250 and 1000 mg L⁻¹, respectively, whereas fruit number increased by up to 63.8% under salinity. Photosynthetic rate increased from 12.58 to 16.19 μmol CO₂ m⁻² s⁻¹ and stomatal conductance from 0.235 to 0.325 mol H₂O m⁻² s⁻¹. Fruit quality was also enhanced, with soluble solids increasing from 5.9 to 7.1 °Brix, vitamin C from 50.58 to 115.42 mg 100 g⁻¹ FW, and total anthocyanins from 65.7 to 106.2 C3G 100 g⁻¹ FW, indicating a substantial enhancement to the fruit’s nutraceutical quality, particularly at 500 mg L⁻¹ and 1000 mg L⁻¹. These findings demonstrate that the CHTMD system is an effective biostimulant capable of improving tolerance to salt stress by modulating key physiological and biochemical responses, as well as enhancing the functional quality of the fruit. This approach represents a promising and sustainable strategy for strawberry production in agricultural systems affected by salinity.

In soils and substrates, the bioavailability of Zn2+ is generally low. The use of zinc oxide nanoparticles (ZnO-NPs) has emerged as a promising strategy in agriculture to improve zinc availability and stimulate plant growth. Their physicochemical properties and biocompatibility promote greater micronutrient uptake and the regulation of physiological processes in plants. In this study, the effects of five concentrations of ZnO-NPs (0, 100, 250, 500, and 1000 mg L−1) and two application methods (foliar or drench) on the growth, gas exchange, and flowering quality of marigold were evaluated. ZnO-NPs significantly influenced plant growth; plant height and total dry weight increased by 28.6% and 35.2%, respectively, at a concentration of 100 mg L−1. Similarly, the flower diameter increased by 28.6%. The number of inflorescences increased 1.6-fold at 1000 mg L−1, whereas photosynthesis, stomatal conductance, and transpiration increased at 250 mg L−1 (84.4, 242.8, and 168.8%, respectively). Intercellular carbon increased by 79.3% with the application of 100 mg L−1, and SPAD units increased by 27.2% with the application of 1000 mg L−1. The application of ZnO-NPs significantly improved plant growth and physiological processes, demonstrating their potential as an efficient strategy to optimize crop productivity and quality.