The Keitt mango tree has a low canopy that leads to an increase in sunburned fruits. Hence, the fruit quality is markedly reduced due to the fruit being exposed to physiological disorders. The sunburn injury problem is common due to high levels of solar radiation and the low number of leaves, which minimizes the protection of small, newly formed fruits. Kaolin spray has emerged as a promising approach for mango trees since it improves vegetative growth, yield, and fruit quality in new lands. This search aimed to study the influence of spraying kaolin on Keitt mango trees grafted on ‘Succary’ rootstock. The treatments were as follows: control, 2%, 4%, and 6% of kaolin. Our results indicated that the applications of kaolin significantly improved leaf area, tree canopy volume, photosynthesis pigments such as chlorophyll-a and b, carotenoids of leaf and yield (kg/tree), and the physical and chemical characteristics of Keitt mango cultivar in comparison with the control. A higher concentration of kaolin decreased the leaf content of antioxidants such as total phenolic, total flavonoid, CAT, POX, and PPO enzyme activities. Furthermore, the number of sunburned fruits was significantly reduced after the application of kaolin in comparison to control fruits. Regarding vegetative growth, our results indicated that adding kaolin at 6% enhanced the leaf surface area and tree canopy volume compared to the control and other treatments. A similar trend was noticed regarding yield and fruit quality, whereas the best values were obtained when kaolin was sprayed at a concentration of 6%. In conclusion, the application of kaolin can improve the production and fruit quality of Keitt mango trees by reducing the effects of adverse summer conditions.

Many techniques have been and are being made to find alternatives to water-saving practices. Among them, Partial root drying (PRD), one effective approach, plays a major role in reducing the harmful effects of water deficit stress. Field experiments were carried out on mango trees for a private farm in Egypt over the course of two years, 2020/2021 to 2021/2022, in an area with sandy soil, hot summer conditions, and cold and rainy winter conditions. In the experiment that was carried out, the experimental design included using different irrigation strategies (I1, 100% full irrigation “FI”; I2, 75% FI; I3, 50% FI; and I4 (PRD), 50% FI) in the main plot and different amounts of organic mulch in the soil (L0, no layers of organic soil mulch, used as a control; L1, a single layer of organic soil mulch; L2, two layers of organic soil mulch; and L3, three layers of organic soil mulch) in subplots of the main plot in order to inspect the impact of the treatments on yield, water productivity, and energy usage under arid conditions. To meet the study’s objective, two field experiments were carried out at a private farm. Our results demonstrate a general decrease in water stress and salt accumulation inside the root-zone area with PRD and L3. During the 2020/2021 and 2021/2022 seasons the PRD strategy increased fruit yields by 3.7 and 7.3% and water productivity by 51.9 and 53.1%, respectively, compared with the control treatment (I1) while reducing the amount of applied irrigation water by 50%. The PRD strategy along with organic mulching showed superior results with respect to increasing mango yields and water productivity. In general, PRD can be used as a good technique to save water and energy by up to 50% while enhancing productivity, ultimately improving mango yields under arid climatic conditions. Thus, it may prove a good adaptation strategy for current and future water shortage scenarios involving climate change.

Nowadays, the production of new mango cultivars is increased in many countries worldwide. The soil application of hydrogel represents a novel approach in the fruit trees industry. This investigation aims to study the effect of adding hydrogel (as soil conditioner) on the growth and yield of Shelly cv. mango trees. The experimental groups were assigned to a control group and three other treated groups, including 250, 500, or 750 g hydrogel∙tree⁻¹. The results demonstrated that all applications of hydrogel composite had higher vegetative growth parameters, yield, and fruit quality characteristics of Shelly cv. mango trees compared to the control. The treatment of 750 g hydrogel∙tree⁻¹ had higher values of vegetative growth parameters such as the leaf area, shoot length and tree canopy volume, compared to the control group and the other treatments. Similarly, higher values for yield and fruit quality were observed in the treatment of 750 g hydrogel∙tree⁻¹. In conclusion, different amounts of hydrogel agent can improve the production and fruit quality of Shelly cv. mango trees in arid and semi-arid conditions in a dose-dependent manner.

Pruning is an essential practice that helps control branch growth, optimize fruit size, and enhance fruit tree productivity. This study focused on ‘Valencia’ orange trees, which had experienced a decline in productivity after being cultivated on reclaimed lands for several years. The aim was to explore the impact of pruning intensity on vegetation growth, fruit yield, productivity, and fruit quality in these orange trees. The study involved 35-year-old ‘Valencia’ orange trees, which were subjected to four different levels of pruning. The pruning treatments included: T1—no pruning (control group), T2—light pruning (removal of 25% of main branches), T3—moderate pruning (removal of 50% of main branches), and T4—heavy pruning (removal of 75% of main branches). Each season, these pruning measures were consistently carried out on 15 February. The results indicated that the severity of pruning directly influenced vegetative growth parameters, such as shoot length and leaf area. As the pruning intensity increased, so did the growth of the vegetation. However, the overall volume of the tree’s canopy decreased compared to the control group. These findings provide insights into the relationship between pruning practices and the growth and productivity of ‘Valencia’ orange trees. The highest fruit yields were observed when pruning was carried out at a severity level of 75%, followed by 50 and 25%. These pruning treatments had a positive impact on various aspects of fruit quality, including weight, size, firmness, juice content, TSS (°Brix), TSS/acid ratio, and vitamin C content. Additionally, pruning contributed to a greater fruit yield per tree and an overall increase in the yield percentage. In essence, the findings suggest that pruning performed at different severity levels in February effectively promotes vegetation growth and enhances the physical and chemical properties of ‘Valencia’ orange trees. Notably, it resulted in a nearly 20% rise in fruit yield compared to the control group.

In years with unfavorable weather, winter frost during the blossoming season can play a significant role in reducing fruit yield and impacting the profitability of cultivation. The mango Naomi cultivar Mangifera indica L. has a low canopy that is severely affected by the effects of frost stress. As a result of the canopy being exposed to physiological problems, vegetative development is significantly inhibited. The current investigation aimed to study the influence of spraying nitric oxide and fogging spray systems on Naomi mango trees grafted on ‘Succary’ rootstock under frost stress conditions. The treatments were as follows: nitric oxide (NO) 50 and 100 μM, fogging spray system, and control. In comparison to the control, the use of nitric oxide and a fogging system significantly improved the leaf area, photosynthesis pigments of the leaf, the membrane stability index, yield, and physical and chemical characteristics of the Naomi mango cultivar. For instance, the application of 50 μM NO, 100 μM NO, and the fogging spray system resulted in an increase in yield by 41.32, 106.12, and 121.43% during the 2020 season, and by 39.37, 101.30, and 124.68% during the 2021 season compared to the control, respectively. The fogging spray system and highest level of NO decreased electrolyte leakage, proline content, total phenolic content, catalase (CAT), peroxidases (POX), and polyphenol oxidase (PPO) enzyme activities in leaves. Furthermore, the number of damaged leaves per shoot was significantly reduced after the application of fogging spray systems and nitric oxide in comparison to the control. Regarding vegetative growth, our results indicated that the fogging spray system and spraying nitric oxide at 100 μM enhanced the leaf surface area compared to the control and other treatments. A similar trend was noticed regarding yield and fruit quality, whereas the best values were obtained when the fogging spray system using nitric oxide was sprayed at a concentration of 100 μM. The application of fogging spray systems and nitric oxide can improve the production and fruit quality of Naomi mango trees by reducing the effects of adverse frost stress conditions.

Pomegranate is one of the most important and widely distributed trees. Boron and zinc are important nutrients for plant growth and fruit quality. Nanotechnology has emerged as one of the most innovative scientific fields in agriculture. This study was conducted to describe the changes in the physiochemical characteristics (weight, diameter, length, firmness and color), as well as the phytochemicals attributes (total phenolics, total flavonoids, ascorbic acid, anthocyanin and antioxidant %) and minerals contents, of pomegranates fruits of the ‘Wonderful’ cultivar as a result of spraying pomegranate trees using nanomaterials (zinc oxide (ZnONPs) and boron oxide (B₂O₃NPs)). In three successive developmental stages (full bloom, 6 weeks after full bloom and one month before harvest time), the trees were sprayed with 0.25, 0.5 and 1 g/L ZnONPs, as well as 0.25, 0.5 and 1 g/L B₂O₃NPs during the 2021 and 2022 seasons. The application of ZnONPs and B₂O₃NPs influenced the qualitative characteristics of the fruits in the studied seasons. The highest marketable % was observed for the 0.50 and 1 g/L ZnONPs and 1 g/L B₂O₃NPs compared to the other treatments. Also, a positive effect was recorded for the ZnONPs and B₂O₃NPs on the fruits’ physical properties. All of the ZnONP and B₂O₃NP treatments resulted in increasing the total phenolic, flavonoid, anthocyanin and ascorbic acid contents and the antioxidant activity in the pomegranate juices. In conclusion, our results suggest that spraying pomegranate trees with ZnONPs and B₂O₃NPs improves the marketable fruit, enhances the fruit quality and increases the bioactive components and antioxidant activity.