Impact of Foliar-Applied Iron (Fe) and Zinc (Zn) Nanoparticles on Quinoa Growth and Biochemical Characteristics under Drought Stress

Amaranthaceae annual Chenopodium quinoa Willd seeds have more protein, fiber, B vitamins, and minerals than most seeds. In recent years, the cultivation area and consumption of quinoa have increased in the country due to its nutritional properties and ability to grow in harsh environmental conditions. Based on climate change scenarios, long periods of drought are expected, which emphasizes the need for planting and developing new plants that are adapted to these conditions. Quinoa's morphological, biochemical, and physiological responses to nanoparticle Fe and Zn foliar treatment during drought stress were examined. Quinoa development was also compared to zinc and iron. With nutrient supplementation, a 2019 drought experiment assessed quinoa growth and quality. Quinoa (Giza1 cultivar) was evaluated for morphological, biochemical, and physiological parameters throughout two reproductive stages (50 and 100% blooming stage) and two drought stress levels (85% and 85% soil water). Foliar micronutrient applications (control, Zn(ZnSO4), Fe(FeSO4), Zn+Fe, nano-Zn, nano-Fe, nano-Zn + nano-Fe) were studied. Drought stress greatly reduced plant height, main and lateral branch numbers, leaf number, inflorescence length, leaf, stem, and seed dry weight, wet and dry plant weights, and seed output. Foliar fertilizer increased plant height, main and lateral branch numbers, leaves, inflorescence length, stem, seed dry weights, and plant wet and dry weights. Iron and zinc nanoparticles were better for nutrition. Drought stress affects quinoa production less with fertilizer. Also, most metrics were negatively affected by drought stress; however, foliar nano-Fe and nano-Zn at 50% flowering minimized its negative effects. High protein, proline, soluble carbohydrates, water, photosynthetic pigments, antioxidant enzyme activity, and low malondialdehyde. Drought stress-application time-nutrient correlations were significant in most parameters. At 50% blooming, nano-Fe and nano-Zn treatments had the highest protein, proline, soluble carbohydrates, and antioxidant enzyme levels under drought stress.