Effect of Graft and Nano ZnO on Nutraceutical and Mineral Content in Bell Pepper

The objective of this experiment was to evaluate the effects of grafting, zinc oxide nanoparticles (ZnO NPs), and their interaction on the nutritional composition of bell pepper plants. The treatments evaluated included grafted and non-grafted pepper plants with four concentrations of ZnO NPs (0, 10, 20, 30 mg L^-1) applied to the foliage. The following parameters were evaluated: content of N, P, K⁺, Ca²⁺, Mg²⁺, Mn²⁺, Zn²⁺, Fe²⁺, Cu²⁺, total antioxidants, ascorbic acid, total phenols, glutathione, total proteins, fruit firmness, and total soluble solids. Grafting increased the content of N 12.2%, P 15.9%, K⁺ 26.7%, Mg²⁺ 20.3%, Mn²⁺ 34.7%, Zn²⁺ 19.5%, Fe²⁺ 18.2%, Cu²⁺ 11.5%, antioxidant capacity 2.44%, ascorbic acid 4.63%, total phenols 1.33%, glutathione 7.18%, total proteins 1.08%, fruit firmness 8.8%. The application of 30 mg L^-1 ZnO NPs increased the content of N 12.3%, P 25.9%, Mg²⁺ 36.8%, Mn²⁺ 42.2%, Zn²⁺ 27%, Fe²⁺ 45%, antioxidant activity 13.95%, ascorbic acid 26.77%, total phenols 10.93%, glutathione 11.46%, total proteins 11.01%, and fruit firmness 17.7% compared to the control. The results obtained demonstrate the influence of the use of grafts and ZnO NPs as tools that could improve the quality and nutrient content in fruits of bell pepper crops.