Salinity stress is a severe environmental stress that affects plant growth and productivity of potato, a strategic crop moderately sensitive to saline soils. Limited studies are available on the use of combined nano-micronutrients to ameliorate salinity stress in potato plants (Solanum tuberosum L.). Two open field experiments were conducted in salt-affected sandy soil to investigate plant growth, physiology, and yield of potato in response to soil salinity stress under single or combined application of Zn, B, Si, and Zeolite nanoparticles. It was hypothesized that soil application of nanoparticles enhanced plant growth and yield by alleviating the adverse impact of soil salinity. In general, all the nano-treatments applications significantly increased plant height, shoot dry weight, number of stems per plant, leaf relative water content, leaf photosynthetic rate, leaf stomatal conductance, chlorophyll content, and tuber yield, as compared to the untreated control. Furthermore, soil application of these treatments increased the concentration of nutrients (N, P, K, Ca, Zn, and B) in plant tissues, leaf proline, and leaf gibberellic acid hormone (GA3) in addition to contents of protein, carbohydrates, and antioxidant enzymes (polyphenol oxidase (PPO) and peroxidase (POD) in tubers. Compared to other treatments, the combined application of nanoparticles showed the highest plant growth, physiological parameters, endogenous elements (N, P, K, Ca, Zn, and B) and the lowest concentration of leaf abscisic acid (ABA) and transpiration rate. The present findings suggest that soil addition of the aforementioned nanoparticles can be a promising approach to improving crop productivity in salt-affected soils.

Sandy soils with high alkalinity are characterized by low copper (Cu) contents that lead to many deficiency symptoms in plants. Cu deficiency in plants can be corrected using several cheap Cu sources. Nevertheless, the effects that novel sources, such as Cu nanoparticles (NPs), have on plants remain poorly studied. In the present work, we investigated the effect and efficiency of Cu supplementation to onion (Allium cepa L.) plants using Cu sulfate, chelate, or NPs, and compared their effects on bulb quality, yield, and contents of phytochemicals. Two successive seasons (2018/2019 and 2019/2020) of field experiments were conducted in newly reclaimed sandy soils, where plants were sprayed with either 10 ppm CuO NPs, 20 ppm CuSO₄·5H₂O, or 20 ppm of Cu chelates. Overall, Cu deficiency (control) resulted in a significant decrease in yield and all quality traits of onion plants. CuO NPs treatment significantly enhanced growth parameters, including plant height, number of leaves, fresh and dry weight, yield, and bulb quality, compared with Cu sulfate and chelates. This was also the case regarding chemical constituents such as macro- and micro-nutrients, total soluble solids, phytochemical compounds, vitamins, and amino acids. Although Cu sulfate is the cheapest form used for Cu supplementation, results of the present study suggest that CuO NPs was not only safe to use, but also was the treatment that led to the highest onion yield and quality.

A field experiment was conducted to evaluate the effects of calcium (Ca), potassium (K), and silicon (Si) nanoparticles on growth and production under water stress conditions. The combined application of Ca, K, and Si significantly improved the growth of drought-stressed cucumber plants compared to untreated plants. All nanoparticles similarly enhanced total chlorophyll levels, chlorophyll fluorescence (Fv/Fm), photosynthetic rates, and water use efficiency, as well as the accumulation of indole-acetic acid (IAA) and essential nutrients [magnesium (Mg), potassium (K), calcium (Ca), phosphorus (P), and nitrogen (N)] in the leaves of drought-stressed cucumber plants. The foliar application of combined K, Ca, and Si nanoparticles increased the activity of antioxidant enzymes, alleviating drought stress and scavenging reactive oxygen species (ROS). In contrast, the combined application of Ca, K, and Si nanoparticles resulted in a significant reduction in malondialdehyde (MDA) and abscisic acid (ABA) levels compared to the control treatment. Furthermore, the use of K, Ca, and Si nanoparticles, either alone or in combination, notably improved total yield and its components, including fruit weight and the number of fruits. Compared to untreated plants, the combined application of Ca, K, and Si nanoparticles also increased carbohydrates, total soluble solids, ascorbic acid, and total phenol content, while reducing cucurbitacin content.

Background: Peace lily (Spathiphyllum wallisii Regel) is an ornamental indoor plant with promising cut flower market, as well as antiviral, pharmacological and ecological potentials. Water deficiency can have sound effects on the growth performance and aesthetic quality of such plant. The aim of this study was to investigate the consequences of zeolite, biochar, and zeo-char loaded nano-nitrogen application on the growth performance and biochemical components of peace lily under water shortage conditions. An experiment was conducted over two consecutive seasons (2021–2022) at the experimental nursery of Ornamental Horticulture Department, Faculty of Agriculture, Cairo University, Giza, Egypt. Soil amendments; zeolite, biochar, and zeo-char loaded nano-nitrogen were prepared and applied to soil before cultivation. Results: Our results revealed that the new combination treatment (zeo-char loaded nano-N) had an exceeding significant effect on most of the studied parameters. Vegetative traits such as plant height (35.7 and 35.9%), leaf number per plant (73.3 and 52.6%), leaf area (40.2 and 36.4%), stem diameter (28.7 and 27.1%), root number (100 and 43.5%) and length (105.7 and 101.9%) per plant, and fresh weight of leaves (23.2 and 21.6%) were significantly higher than control (commercially recommended dose of NPK) with the application of zeo-char loaded nano-N during the two growing seasons, respectively. Similar significant increments were obtained for some macro- (N, P, K, Mg, Ca) and micro- (Fe, Zn, Mn) elements with the same treatment relative to control. Chlorophyll (18.4%) and total carotenoids (82.9 and 32.6%), total carbohydrates (53.3 and 37.4%), phenolics (54.4 and 86.9%), flavonoids (31.7% and 41.8%) and tannins (69.2 and 50%), in addition to the phytohormone gibberellic acid (GA₃) followed the same trend with the application of zeo-char loaded nano-N, increasing significantly over control. Leaf histological parameters and anatomical structure were enhanced with the new combination treatment in comparison with control. Antioxidant enzymes (catalase and peroxidase), proline and abscisic acid (ABA) exhibited significant declines with zeo-char loaded nano-N treatment relative to control. Conclusion: These findings suggest that incorporating soil amendments with nano- nutrients could provide a promising approach towards improving growth performance and quality of ornamental, medicinal and aromatic species under water deficiency conditions.

Soil salinity causes an annual deep negative impact to the global agricultural economy. In this study, the effects of salinity on early seedling physiology of two Egyptian cotton (Gossypium barbadense L.) cultivars differing in their salinity tolerance were examined. Also the potential use of a low cost mini-rhizotron system to measure variation in root system architecture (RSA) traits existing in both cultivars was assessed. Salt tolerant cotton cultivar ‘Giza 90’ produced significantly higher root and shoot biomass, accumulated lower Na⁺/K⁺ ratio through a higher Na⁺ exclusion from both roots and leaves as well as synthesized higher proline contents compared to salt sensitive ‘Giza 45’ cultivar. Measuring RSA in mini-rhizotrons containing solid MS nutrient medium as substrate proved to be more precise and efficient than peat moss/sand mixture. We report superior values of main root growth rate, total root system size, main root length, higher number of lateral roots and average lateral root length in ‘Giza 90’ under salinity. Higher lateral root density and length together with higher root tissue tolerance of Na⁺ ions in ‘Giza 90’ give it an advantage to be used as donor genotype for desirable root traits to other elite cultivars.