The application of green methods in the synthesis of nanoparticles using plants is a cost-effective and eco-friendly approach. Zinc oxide nanoparticles are of great importance due to their versatile properties. The conditions of synthesis strongly influence the characteristics and functionality of the nanoparticles. The present work studied the biological, green synthesis of zinc oxide nanoparticles (ZnONPs) in the presence of different concentrations of ethanolic extract of Larrea tridentata (10, 20, and 30 mg/mL). The time of the formation of nanoparticles was evaluated at different temperatures and pH values of the reaction medium. The formation of ZnONPs was confirmed by ultraviolet-visible (UV-Vis) and Fourier transform infrared spectroscopies (FT-IR), as well as scanning electron microscopy (SEM). X-ray diffraction analysis (XDR) determined the crystallographic structure of the nanoparticles. Obtained ZnONPs had a size range of 18 to 40 nm. The temperature, reaction time, and pH significantly influenced the nanoparticles’ morphology, size, and aggregation. The impact of chosen ZnONPs was tested on the germination of serrano chili seeds (Capsicum annuum). At 100 ppm, the nanoparticles improved germination percentage, vigor, and seedlings’ growth parameters.

Zinc oxide nanoparticles have gained attention in the last decades due to their versatile applications; in agriculture, they have been used for their multiple benefits. In this study, the effects of zinc oxide nanoparticles, obtained via chemical and biological synthesis and of 70–80 nm in size, on the germination and seedling growth of Capsicum annuum and Solanum lycopersicum seed were determined. The physiological parameters, photosynthetic pigments, the content of total phenols, total flavonoids, as well as the antioxidant capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH), and the enzymatic activity of catalase, peroxidase, and polyphenol oxidase were evaluated. The results indicated that treatment with zinc oxide nanoparticles obtained via green synthesis improved seed germination rate, while chemically synthesized nanoparticles at higher concentrations decreased germination percentage. In general, the parameters of enzymatic and nonenzymatic antioxidants in treated plants showed significant differences with respect to the control. However, the treatments with the bionanoparticles resulted in more beneficial parameters. Zinc oxide nanoparticles obtained via green synthesis are more effective in generating bioactive compounds and activating the enzyme defense system due to being more biocompatible.

Emerging or alternative crops are those that have been recently introduced in response to new demands and commercial opportunities. The fig has been introduced as an alternative fruit crop in Mexico due to its high nutritional, nutraceutical, and antioxidant capacity. A total of 644 points of presence were downloaded and filtered according to climatic ranges and agricultural areas, leaving 68 records. The MaxEnt algorithm was used to develop the habitat suitability models for current and future climate. The bioclimatic variables of the global circulation models, Hadley Centre Global Environment Model version 2-EarthSystem (HADGEM2-ES) and Max Planck Institute for Meteorology-Earth System Model Low Resolution (MPI-ESM-LR), were used under scenarios 2.6 and 8.5. The changes in the fig area for Mexico were analyzed based on the generated models. Under the current climate, 359,575.76 km² were estimated for 2050, and a loss of area for the excellent category was estimated for both models and scenarios; however, for the MPI-ESM-LR model projected to 2070, an increase of 5.51% and 0.39% was estimated for scenarios 2.6 and 8.5, respectively. The effect of climate change on agronomic species such as figs will be expressed in variations in climatic ranges and areas suitable for their development. The results of this study reveal the negative and positive effects of climate change on fig habitat suitability in Mexico. The dynamics of changes in surface area will be reflected mainly in northern and central Mexico.

The low availability of micronutrients in the soil leads to a deficit of these micronutrients in crops, causing malnutrition in the population. Approximately 3,000 million people in the world have health problems caused by inadequate Zn intake. Agronomic biofortification is a way to produce crops rich in micronutrients and mitigate malnutrition problems. Nano biofortification with zinc oxide nanoparticles (NPs-ZnO) is a good strategy to mitigate and increase the nutritional content of the edible part of the plant. The aim was to determine the effect of foliar spraying with NPs-ZnO on yield and biosynthesis of enzymatic and non-enzymatic antioxidant compounds and their bioaccumulation. In this study, the effect of foliar fertilization with NPs-ZnO: 0, 25, 50, 75, and 100 mg L-1, on yield, the content of bioactive compounds and their bioaccumulation in grapevine berries was evaluated. The distribution of the treatments was under a completely randomized design, each treatment consisted of 10 plants, each representing one experimental unit. The treatments were applied by foliar sprays at fruit formation, in veraison and 15 days before harvest. Foliar spraying with NPs-ZnO positively modifies yield, the content of bioactive compounds, and their bioaccumulation. Doses of 50-75 mg L-1 of NPs-ZnO increased crop yield, and oenological parameters. In addition, all doses evaluated modified enzymatic and non-enzymatic antioxidants, and improving Zn concentration in grapevine berries. Foliar spraying of NPs-ZnO is an alternative to improve grape quality and yield, in addition to enriching its nutritional and antioxidant content.

The application of zinc oxide nanoparticles prepared by green synthesis (GS-ZnONPs) has demonstrated essential benefits in boosting the clean and sustainable production of agricultural crops worldwide. In this part of the study we evaluate the effect of GS-ZnONPs foliar spraying on the yield, nutraceutical quality, capsaicin concentration, and antioxidant metabolism of chili fruit (Capsicum annuum L., CHISER-522 variety) grown under greenhouse conditions. GS-ZnONPs treatments were applied at concentrations of 10, 20, 30, 40, and 50 ppm every 15 days post-transplant, with the control group treated only with distilled water. The results indicated that treatments with 40 and 50 ppm of GS-ZnONPs significantly improved fruit yield, length, and fruit amount. At the same time, the concentrations of 30 and 40 ppm significantly increased the levels of vitamin C, bioactive compounds, and antioxidant capacity, indicating a better nutraceutical quality of the fruit. In addition, an increase in the catalase activity and the content of macro and micro-minerals in the fruit treated with GS-ZnONPs was observed. Our results suggest that the foliar application of GS-ZnONPs acts as a nanobioestimulant, offering an excellent biotechnological tool for developing agroecological strategies to increase the nutraceutical and antioxidant quality of chili pepper fruit.

This research aimed to evaluate the effectiveness of the biosynthesized spherical zinc oxide nanoparticles (BZnONPs) applications on morphological and physiological indices of serrano pepper plants cv. ‘Chiser-522’. The treatments applied by foliar spray every 15 days from 20 days after transplantation consisted of 10, 20, 30, 40, and 50 ppm of BZnONPs and control (distilled water). A completely randomized design was used with six treatments and fifteen replicas per treatment. Morphological and physiological characteristics such as crop growth rate (CGR), net assimilation rate (NAR), leaf area index (LAI), photosynthetic pigments, and phytochemical compounds were evaluated. The results indicated that the plants treated with 30 and 40 ppm of BZnONPs had higher height, thicker stems, longer roots, and higher CGR, NAR, and LAI than control. Their amounts of photosynthetic pigments and antioxidant compounds were also increased compared to those of the other treatments. Therefore, we conclude that BZnONPs are promising technology that significantly influences chili pepper cultivation's physiological and morphological development at low-level exposures.