Applications of metal oxide nanoparticles in the agriculture sector are being extensively included as the materials are considered superior. In the present work, zinc oxide nanoparticle (ZnO NPs), with a developing fertilizer, is applied in the fortification of rice grain yield and nutrient uptake enhancement. To evaluate the role of ZnO NP, two field experiments were conducted during the 2018 and 2019 seasons. ZnO NPs were small, nearly spherical, and their sizes equal to 31.4 nm, as proved via the dynamic light scattering technique. ZnO NPs were applied as a fertilizer in different concentrations, varying between 20 and 60 mg/L as a foliar spray. The mixture of ZnSO₄ and ZnO NP₄₀ ameliorated yield component and nutrients (N, K, and Zn) uptake was enhanced compared to traditional ZnSO₄ treatment. Nevertheless, the uptake of the phosphorous element (P) was adversely affected by the treatment of ZnO NPs. Thus, treatment via utilizing ZnO NPs as a foliar with a very small amount (40 ppm) with of basal ZnSO₄ led to a good improvement in agronomic and physiological features; eventually, higher yield and nutrient-enriched rice grain were obtained.

In paddy fields, overuse of nitrogen fertilizer to maximize yields can lead to excessive economic loss and degradation of the environment. Therefore, studying the effects of urea–chitosan nanohybrid as a slow released source of nitrogen fertilizer on rice cultivation was the aim of our study. The effects of fertilization applications, namely: CU: control treatment; U1: application of a full recommended dose of classical urea (165 kg N ha⁻¹); U2: adding recommended dose of classical urea by 80% + exogenous urea–chitosan nanohybrid 250 mg N/L; U3: adding recommended dose of classical urea by 80% + exogenous urea–chitosan nanohybrid 500 mg N/L; U4: adding recommended dose of classical urea by 60% + exogenous urea–chitosan nanohybrid 250 mg N/L; U5: adding recommended dose of classical urea by 60% + exogenous urea–chitosan nanohybrid 500 mg N/L; U6: adding recommended dose of classical urea by 40% + exogenous urea–chitosan nanohybrid 250 mg N/L; and U7: adding recommended dose of classical urea by 40% + exogenous urea–chitosan nanohybrid 500 mg N/L on growth indicators, yield-related components, grain productivity, and N uptake status of rice plants were investigated during two successive seasons. As a result, significant achievements concerning growth, yield and yield-related traits were obtained when rice plants were fertilized with exogenous urea–chitosan nanohybrid (i.e., 500 mg N/L) + 60% classical urea without a significant decline in the studied traits compared to the full recommended dose of classical urea. Accordingly, this investigation revealed that chitosan nanohybrid at 500 mg N/L as a compensatory alternative can be used in saving 40% of classical urea requirement.

Plant viruses are a global concern for sustainable crop production. Among the currently available antiviral approaches, nanotechnology has been overwhelmingly playing an effective role in circumventing plant viruses. Alfalfa mosaic virus (AMV) was isolated and identified from symptomatic pepper plants in Egypt using symptomatology, serological tests using the direct ELISA technique, differential hosts and electron microscopy. The virus was biologically purified from a single local lesion that developed on Chenopodium amaranticolor. The AMV infection was further confirmed using an AMV coat protein-specific primer RT-PCR. We further evaluated the antiviral potential of chitosan nanoparticles (CS-NPs) and chitosan silver nanocomposites (CS-Ag NC) in different concentrations against AMV infections in pepper plants. All tested concentrations of CS-NPs and CS-Ag NC induced the inhibition of AMV systemically infected pepper plants when applied 24 h after virus inoculation. The foliar application of 400 ppm CS-NPs or 200 ppm CS-Ag NC produced the highest AMV inhibitory effect (90 and 91%) when applied 24 h after virus inoculation. Treatment with CS-NPs and CS-Ag NC considerably increased the phenol, proline and capsaicin contents compared to the infected plants. Moreover, the agronomic metrics (plant height, fresh and dry pod weights and number of pods per plant) were also significantly improved. According to our results, the potential applications of CS-NPs and CS-Ag NC may provide an effective therapeutic measure for better AMV and other related plant virus management.

Cucumber mosaic virus (CMV) is a destructive viral pathogen of vegetables, fruits, grains, and ornamentals across the globe. This study investigated the comparative antiviral efficacy of chitosan–salicylic acid nanocomposite (Ch/SA NC) and salicylic acid (SA) against CMV in cucumber plants. Transmission electron microscopy (TEM) analyses revealed that Ch/SA NCs can aggregate on the viral coat protein surface, suggesting direct nanoparticle–virus interaction. Greenhouse trials showed that Ch/SA NC, particularly at 90 ppm applied 24 h before CMV inoculation, was the most effective treatment in reducing disease severity and viral load. SA at the same concentration also conferred significant protection when used prophylactically. An RT-PCR analysis confirmed suppression or complete silencing of CMV coat protein gene expression, especially Ch/SA NC-treated plants. Both treatments significantly enhanced the physiological condition of infected plants, including restoration of chlorophyll a, chlorophyll b, and carotenoids, and elevated levels of total phenolics, flavonoids carbohydrates, and proteins. In addition, they boosted the key antioxidant enzymes activities (POX, PPO, SOD) and improved vegetative growth indicators such as plant height, fruit fresh weight, and number of fruits per plant. These results indicate that Ch/SA NC and SA not only inhibit CMV replication but also stimulate host defense responses, improving overall plant health. The strong antiviral effect is likely due to the dual action of Ch/SA NC: direct virus binding and induction of systemic acquired resistance (SAR). Given their efficacy and eco-friendly nature, especially the Ch/SA NC, these treatments offer a promising strategy for integrated viral disease management. Future studies should investigate long-term environmental safety, molecular mechanisms, and field-level applicability.

Solar energy has become an energy source for a wide range of uses, including in solar cookers, due to its availability, cleanliness, environmental friendliness, and sustainability. In this study, an indirect solar cooker was investigated by measuring its thermal performance using a Graphene Oxide (GO) nanofluid. Water, GO (250 ppm)-water, and GO (500 ppm)-water were used as heat transfer fluids. The experimental set-up consisted of the cooking part and a solar collector, which are the two essential elements in indirect solar cookers. The cooking part was a wooden box solar cooker, and the parabolic trough solar collector was a polished stainless steel structure. The solar cooker was assessed using the stagnation test and load test as well as energy and exergy measurements. According to the test results, the averaged F₁ was 0.1 for the base fluid water, 0.11 for GO (250 ppm)-water, and 0.13 for GO (500 ppm)-water. In addition, using a GO nanofluid instead of water in the solar cooker, the system’s thermal performance, energy, and exergy efficiency were improved. The use of the GO (250 ppm)-water and GO (500 ppm)-water nanofluids instead of water in the system improved the overall energy efficiency of the system by 3.3 and 4.2%. Moreover, using GO (500 ppm)-water allowed for achieving superior performance.

The journal retracts the article titled “Green Synthesis of Zinc Oxide Nanoparticles: Fortification for Rice Grain Yield and Nutrients Uptake Enhancement”