Iron (Fe) is required for most metabolic processes, including DNA synthesis, respiration, photosynthesis, and chlorophyll biosynthesis; however, Fe deficiency is common in arid regions, necessitating additional research to determine the most efficient form of absorbance. Nano-fertilizers have characteristics that are not found in their traditional equivalents. This research was implemented on Washington navel orange trees (Citrus sinensis L. Osbeck) to investigate the effect of three iron forms—nano (Fe-NPs), sulfate (FeSO₄), and chelated (Fe-chelated)—as a foliar spray on the growth, fruiting aspects, and nutritional status of these trees compared to control. The highest values of the tested parameters were reported when the highest Fe-NPs level and the highest Fe-chelated (EDTA) rate were used. Results obtained here showed that the spraying of the Washington navel orange trees grown under similar environmental conditions and horticulture practices adopted in the current experiment with Fe-NPs (nanoform) and/or Fe-chelated (EDTA) at 0.1% is a beneficial application for enhancing vegetative growth, flower set, tree nutritional status, and fruit production and quality. Application of Fe-NPs and Fe-chelated (EDTA, 0.1%) increased yield by 32.0% and 25% and total soluble solids (TSS) by 18.5% and 17.0%, respectively, compared with control. Spraying Washington navel orange trees with nano and chelated iron could be considered a significant way to improve vegetative growth, fruit production, quality, and nutritional status while also being environmentally preferred in the arid regions.

Nano fertilization is a precision approach to sustain economically viable and environmentally compatible crop production. The objective of our study was to evaluate the effects of different sources and rates of iron (Fe) fertilization as an essential micronutrient on the growth, physiological processes, and yield of greenhouse-grown tomatoes (Solanum lycopersicum cv. Bigdena F1). A factorial experiment in randomized complete block design with four replications was conducted using three sources (Conventional, FeCl_3.6H₂O [Conv-Fe]; Chelated with 6% Fe [Che-Fe]; and Nano Fe₂O₃ [Nano-Fe], alpha, 99%, 30–50 nm) and rates of Fe (0, 50, and 100 mg/kg soil) during 2015 and 2016 growing seasons. Averaged across Fe rates, the Nano-Fe significantly increased plant height, leaf number and area, shoot and root fresh and dry weights, and Soil Plant Analysis Development (SPAD) readings. Nano-Fe at 100 mg/kg significantly increased plant height, leaf number and area, fresh and dry weights of shoot and roots, gas exchange parameters i.e., photosynthesis (Pn), stomatal conductance (gs) and transpiration (E) rates, total yield, and yield components of tomatoes in comparison to the other rates. While there were no significant simple and interactions of Fe on plant physiological processes, the Nano-Fe had the highest Pn with an associated decrease in E and an increase in gs. Nano-Fe, when applied at 100 mg/kg, produced the highest fruit diameter, fruit numbers/plant, total fruit weight/plant, mean fruit weight/plant, total fruit numbers/ha, and total fruit weight/ha, followed by Nano-Fe at 50 mg kg as compared with other Fe sources and rates. In conclusion, Nano-Fe fertilization is more effective than Conv-Fe and Che-Fe fertilizations across growing seasons to improve growth characteristics and metabolic processes of tomato plants, as Fe plays an important role in photosynthates accumulation and translocation. Nano-Fe increased tomato yield by 11% compared to Conv-Fe and Che-Fe fertilizers and will greatly improve farmers’ profitability.

Two filed experiments were carried out at a private farm in Behaira Governorate, Egypt during 2012 and 2013 summer seasons. Experiments aimed to study the effect of two widely marketing (commercial safe compounds). First, is a seaweed extract (with commercial name of sea weed) at 1, 2 and 4 ml/l while the second is a mixture of free amino acids (with plant origin and commercially name is sway) at 2,4and 8 ml/l and seaweed at 2 ml/l + amino acids at 4 ml/. The two compounds were applied as foliar spray three times on common bean plant (Phaseolus vulgaris L.) starting at 25 days of plant age with 10 days intervals between each spray and others. The obtained results clearly indicate that different applied treatments increased estimated or measured growth characteristics i.e., plant height, stem diameter, number of branches and leaves/ plant, total leaf area /plant, dry weight of shoots and specific growth rate as well as paralley increase of photosynthetic pigments and total chlorophyll SPDS with increasing seaweed and amino acid sprayed levels at the age of 65 days after sowing during 2012 and 2013 seasons. As for the yield and yield components i.e., number of pods/plant, pod weight (g) , number of seeds per pod, number of fully seeds /plant, , weight of 100 seeds (g), number of seeds/ plant, seed yield (g) /plant and the harvest index. Also, biochemical constituents of N, P, K, Mg, Ca, Fe, Zn, Total carbohydrates and crude protein in leaves at 65 days of plant age were existed in the two assigned seasons. In addition, the most effective treatments was that of sea weed at 2 ml/l combined with the amino acids at 4 ml/l was the most effective treatment in this respect.

Micronutrient additives for sugar beet growth and development are very important, especially in the alkaline Egyptian soil. A two-year (2017 and 2018) field experiment was conducted in the Sakha Agricultural Research Station of Agricultural Research Center, Egypt, to study the effect of the foliar treatments with micronutrients including zinc (Zn) at rates of 50 and 100 mg L⁻¹, boron (B) at rates of 50 and 100 mg L⁻¹, and molybdenum (Mo) at rates of 20 and 40 mg L⁻¹ on the morphological and physiological features as well as root characteristics of sugar beet (Beta vulgaris L.). Results showed that the Zn, B, and Mo foliar treatments at the two concentrations increased the growth parameters of roots, that is, root diameter, root length, root fresh weight, and root dry weight. Likewise, the foliar applications with Zn, B, and Mo at the two applied concentrations significantly increased nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) contents in the treated sugar beet leaves and roots. The high concentration of Zn (100 mg L⁻¹) and Mo (40 mg L⁻¹) yielded the highest of sucrose percentage, TSS percentage, purity percentage, sugar yield, root yield, and improved yield quality as well. The foliar treatments with Zn at a rate of 100 mg L⁻¹ and Mo a rate of 40 mg L⁻¹ showed a high capacity for enhancing growth and yield characteristics of sugar beet in the alkaline Egyptian soil probably due to balancing nutrients uptake and translocation.

Sweet pepperincludes several vitamins and is regarded as a great source of bioactive nutrients, such as carotenoids and phenolic compounds, for human growth and activities. This work aimed to investigate the effects of the soil addition of growth stimulants, namely, effective microorganisms (EM), compost tea, fulvic acid, and yeast extract, and foliar applications of seaweed extract, on the vegetative growth, enzyme activity, phytohormones content, chemical constituents of plant foliage, fruit yield, and fruit quality of sweet pepper plants (Capsicum annuum L. cv. Zidenka) growing under greenhouse conditions. The results showed that the tallest plant, largest leaf area/plant, and heaviest plant fresh and dry weights were recorded after combining a soil addition of yeast extract and foliar spray with seaweed extracts at 3 g/L in two growing seasons. The highest number of fruit/plant, fruit yield/m², fruit values of vitamin C (VC), total sugars, total soluble solids (TSS), and carotenoids, along with the highest leaf of cytokines, P, K, Fe, and total carbohydrates values, were obtained using a soil addition of fulvic acid and spray with seaweed extract at 3 g/L in the two seasons of study. These treatments also provided the lowest abscisic acid, peroxidase, and super oxidase dismutase values in the same conditions. Sweet pepper plants supplemented with compost tea and seaweed extract foliar spray at 3 g/L were the most promising for inducing the highest values of fruit fresh and dry weights, fruit length and diameter, and the leavesrichest in N, Zn, and Mn; inversely, it induced the lowest catalase levels in both seasons. The applications of EM, yeast extract, and seaweed extract could be applied for high growth, mineral levels, enzymatic activity, fruit yield, and nutritional value of sweet pepper fruit and minimizing environmental pollution.

Phytoremediation is a natural approach to use plants for decontaminating soil. A pot-culture factorial experiment in completely randomized design was conducted to evaluate the effects of four levels [0, 25, 50, and 100 mg/kg] of chromium (Cr) with three levels [0, 0.5, and 1-M solution) of plant defense inducer salicylic acid (SA) on growth, physiological processes, and biochemical responses of Malabar spinach (Basella alba). Results showed that Cr significantly decreased vine length (VL), leaf number (LN), leaf area (LA), fresh- (FBM), and dry-biomass (DBM), root length (RL), and dry-matter ratio (DMR). Cr also significantly decreased SPAD (chlorophyll contents), by 9% to 29% and net photosynthesis (Pn) rates, by 36% to 71%, but increased transpiration (E) rates, by 1.5 to 2.7 times and stomatal conductance (C), by 1.7 to 3.5 times, as compared with the control. Proline contents increased with an associated decrease in oxidative enzyme activities such as peroxidase, (POD) and catalase, (CAT) with increasing Cr levels. Cr significantly reduced the Dry Matter Ratio (DMR) (12% to 42%) and LA (10% to 35%), RL -stress (11% to 27%), and SPAD (10% to 28%) stress tolerance indices. The integrated stress tolerance index (IST_Index) of Malabar spinach was reduced (by 6% to 23%) by Cr stress, as compared to the control. SA application, in contrast, partially alleviated the severity of Cr toxicity effects on VL, LN, LA, FBM, DBM, RL, and DMR and increased the SPAD (by 12%), Photosynthesis Net (Pn) (by 53% to 68%), and stomatal conductance (C) (by 35% to 50%), respectively. Furthermore, SA increased plant stress tolerance indices by increasing antioxidant enzymatic functions. SA application recovered the IST_Index at all Cr levels, and the recovery effect on plants was more pronounced by 0.5-M SA than by other SA treatments. The mechanism of stress tolerance as induced by SA application may help plants to better survive and maintain growth in presence of higher Cr contents in soil. Results suggested that SA, as a plant defense inducer, can be exploited for improving Cr phytoremediation potential of Malabar spinach to decontaminate soil.