A field experiment was conducted on date palm trees (Phoenix dactylifera ‘Succary’) cultivated on sandy loam soil from 2017 to 2018. This study investigated the effects of providing water of three different qualities, namely freshwater (FR) and two saline water sources: reclaimed wastewater (RW) and well-water (WE) applied through three irrigation levels representing 50% (I₅₀), 100% (I₁₀₀), and 150% (I₁₅₀) of crop evapotranspiration (ET_c), on the soil water and salt distribution patterns, yield, water productivity (WP), and fruit quality of the ′Succary′ date palm. The electrical conductivity (EC_w) of FR, RW, and WE were 0.18, 2.06, and 3.94 dS m⁻¹, respectively. Results showed that WE applied by the I₁₅₀ treatment had the highest soil water content, followed by RW used in the I₁₀₀ irrigation level and FR with I₅₀, whereas the soil salt content was high for WE applied in the I₅₀ level and low for FR applied by the I₁₅₀ treatment. Deficit irrigation (I₅₀) of date palms with either RW or WE reduced date yields on average 86 kg per tree, whereas the yield increased under over-irrigation (I₁₅₀) with FR to 123.25 kg per tree. High WP values were observed in the I₅₀ treatments with FR, RW, or WE (on average 1.82, 1.68, and 1.67 kg m⁻³, respectively), whereas the I₁₅₀ treatment with each of the three water types showed the lowest WP values. Fruit weight and size were the lowest in the full irrigation (I₁₀₀) with WE, whereas the I₁₅₀ treatment with RW showed the highest values. There were no significant differences in either total soluble solids (TSS) or acidity values when the irrigation level decreased from 100% to 50% ET_c. Compared with both I₅₀ and I₁₀₀ treatments, reduced values of both TSS and acidity were observed in the I₁₅₀ treatment when EC_w decreased from 3.94 to 0.18 dS m⁻¹,. Fruit moisture content decreased with the application of saline irrigation water (i.e., RW or WE). Total sugar and non-reducing sugar contents in fruits were found to be decreased in the combination of RW and I₁₅₀, whereas the 50% ET_c irrigation level caused an increment in both parameters. These results suggest that the application of deficit irrigation to date palm trees grown in arid regions, either with FR or without it, can sufficiently maximize WP and improve the quality of fruits but negatively affects yield, especially when saline water is applied. The use of saline water for irrigation may negatively affect plants because of salt accumulation in the soil in the long run.

Ficus palmata is an important fig species that produces edible and nutritious fruit and possesses several therapeutic uses. This study reports an effective method for the micropropagation of F. palmata using nodal explants. In vitro shoots were cultured for 7 weeks onto MS medium fortified with different concentrations of cytokinins, light intensities, sucrose concentrations, and light/dark incubation treatments. Optimal axillary shoot proliferation (10.9 shoots per explant) was obtained on a medium containing 30 g/L sucrose and supplemented with 2 mg/L 6-benzylaminopurine (BAP) under 35 μmol/m²/s light intensity. Dark incubation limited the foliage growth but favored shoot elongation and rooting compared with light incubation. Elongated shoots, under dark conditions, were rooted (100%; 6.67 roots per explant) onto MS medium containing 1 mg/L indole-3-acetic acid (IAA) and 1.5 g/L activated charcoal. The micropropagated plantlets were acclimatized with a 95% survival rate. In this study, the genetic fidelity of micropropagated F. palmata clones along with their mother plant was tested using randomly amplified polymorphic DNA (RAPD), inter-simple sequence repeats (ISSR), and start codon targeted (SCoT) molecular markers. The genetic similarity between the micropropagated plantlets and the mother plant of F. palmata was nearly 95.9%, assuring high uniformity and true-to-type regenerated plants. Using micropropagated F. palmata plantlets as a rootstock proved appropriate for the grafting F. carica ‘Brown Turkey’. These findings contribute to the commercial propagation and production of the fig crop.

Zinc deficiency is common under heat stress, and further research is needed to determine how to enhance the fruit quality of mango trees through the use of three forms of zinc, namely Zn-NPs, zinc sulfate (ZnSO₄), and chelated zinc (Zn-chelated), as a foliar spray. This research was carried out using ten treatments to investigate the effect of zinc forms on the fruit quality of Timor mango trees. With a few notable exceptions, every fruit quality measurement (physical characteristics, chemical properties, mineral contents, and antioxidant compounds) responded to every treatment looked into; however, the extent of the reaction differed depending on the fruiting measurement. Furthermore, the Zn-NPs created a larger difference in the fruiting measurements than the ZnSO₄ and Zn-chelated forms. ZnO NPs at 100 ppm ranked first, followed by ZnO NPs in the first spray and zinc EDTA in the second spray, followed by ZnO NPs in the first spray and ZnSO₄ in the second, for all mineral content and antioxidant compound measurements and most of the fruit physico-chemical characteristics. In contrast, the lowest levels of minerals and antioxidant compounds and most of the fruit physico-chemical characteristics were found in the controls. The outcomes of the other treatments after the three treatments lay somewhere between these two extremes, and this pattern was detected throughout two seasons. Spraying Timor mango trees with nano, chelated, and sulfate zinc can be considered a safe and environmentally friendly natural method for improving fruit quality in abiotic stress regions.

This study comprised of five different integrated fertilizers of calcium nitrate Ca(NO₃)₂ with ammonium sulphate (NH₄)₂SO₄ ratios (0%:100%, 10%:90%, 20%:80%, 30%:70%, and 40%:60%) to enhance the physico-chemical properties, and the antioxidant and nutritional compounds of pomegranate fruits cv. ‘Wonderful’. The results discovered that the application of Ca(NO₃)₂:(NH₄)₂SO₄ in different ratios significantly affected all measured parameters. Among integrated fertilizers, the 30%:70% combination showed an increment of 10.8% in fruit weight, 2.9% in fruit length, 11.8% in fruit volume, and 7.0% in fruit diameter. Similarly, total soluble solids, vitamin C, anthocyanin, total sugars, and reduced sugars, were also increased by 11.2%, 14.6%, 20.2%, 7.4%, and 5.2%, respectively. Likewise, values of both color variations from green to red (a*) and from blue to yellow (b*), and chroma, were also increased by 13.8%, 16.6%, and 14.4%, respectively. Moreover, the application of Ca(NO₃)₂:(NH₄)₂SO₄ at a ratio of 40%:60% showed 25.1% decrease in titratable acidity, and 45.4% and 27.0% increase in maturity index and peel luminosity, respectively. Additionally, the 30%:70% combination showed an increment of 30.9% in total phenolic content, 70.5% in total tannin content, and 43.6% in total flavonoid content. Additionally, it showed 25.8% and 1.7% decrease in pH and moisture content, respectively. Moreover, P, K, Ca, Mg, Na, Fe, Mn, Zn, Cu, and Ni in fruit increased by different increments by application of the 30%:70% with an increasing range of 28% to 175%. A non-reducing sugar increase was observed at an application of Ca(NO₃)₂:(NH₄)₂SO₄ at a ratio of 20%:80% by 47.0%. The findings of this study suggest that using calcium nitrate with ammonium sulphate at a ratio of 30%:70%, using the fertigation approach during the growth season, could be a safe, natural, and novel method for the pomegranate cv. ‘Wonderful’ to improve fruit quality, and its amount of antioxidants—specifically, phenolics, vitamin C, anthocyanin, and fruit minerals—with health benefits at harvest.

In order to improve the resistance of apples to stresses (abiotic stresses) during hot and dry summers to enhance their productivity and marketability, Anna apple trees were treated with aminoethoxyvinylglycine (AVG), 1-methlcyclopropene (1-MCP), and naphthalene acetic acid (NAA), alone, or in combination, in two successive seasons. All treatments significantly increased the yield per tree, the average fruit volume, fruit diameter, and fruit weight compared to the control (growing under hot and dry summers without any treatments). All treatments significantly reduced the apple size, total soluble solid (TSS) content, anthocyanin content, carotenoid content, total sugar solids, and sugar percentage, and they led to fruit softening, loss of fruit weight, firmness, breakdown percentage, as well as a decreased polyphenol oxidase and peroxidase activity at one-week post-harvest (except for 20-ppm NAA) in comparison with the control. Trees treated with 320-ppm 1-MCP + 250-ppm AVG exhibited maximum yield per tree, fruit firmness, and no-reducing sugars or starch. On the other hand, the 20-ppm NAA produced the maximum TSS content, total sugars, with a reduced sugar percentage, carotenoid and anthocyanin fruit content, and (TSS)/acidity ratio. The application of 320-ppm 1-MCP + 250-ppm AVG effectively delayed the harvest for 14 days compared to the control. Our results show that the sprays of NAA and inhibitors of ethylene had a significant effect on the productivity and marketability of Anna apples under abiotic stresses.

The management of mango orchards is beset with a number of issues, including micronutrient deficits and significant fruit drop, which both contribute to decreases in mango tree output. Among these micronutrients, zinc is vital for increasing agricultural productivity, ensuring crop sustainability, and improving plant nutritional status during the growing season. To overcome zinc (Zn) deficiencies, this study was carried out during two successive seasons in an expected “Off” year (2022) and an expected “On” year (2023) on mature mango trees cv. Timor. To ameliorate this Zn deficiency, the effect of zinc in three forms—zinc oxide nanoparticles (ZnO NPs), sulfate (ZnSO₄), and chelated (Zn-chelated)—as a foliar sprayon leaves’ mineral, chlorophyll, total carotenoids, and total carbohydrate contents and productivity were studied. Ten spray treatments were used in this study, including nano zinc (100 ppm), zinc sulfate (0.1%), and chelated zinc (0.2%) on two occasions, 7 January and 4 weeks after the first application, either alone or in combination with each other as compared to the control. In both study seasons, the results showed that all the zinc forms in mineral, chelated, or nano form had a positive effect on the number of flowers per panicle, the percentage of fruit set, the number of fruits per panicle, and the number of fruits per tree, and it decreased the percentage of fruit drop. Furthermore, all zinc forms significantly increased the leaf N, P, K, Ca, Mg, Cu, Fe, Mn, B, and Zn contents (%), and all the treatments improved the chlorophyll, total carotenoid, and total carbohydrate contents compared with the other treatments. The most effective treatment was two applications of nano zinc at 100 ppm in terms of the nutritional status and productivity of Timor mango trees.