Although chemical fertilization has gained a lot of attention due to its ability to increase the yield of fruit trees, it has been known to cause numerous environmental problems such as soil deterioration, alleviating beneficial microorganisms, and reducing fruit quality and safety. Hence, today, we aim to reduce these problems by using eco-friendly and sustainable biostimulants to promote nutritional status, yield, and quality. The effect of wood vinegar (WV) on mango production has yet to be investigated. Therefore, a field trial was conducted during the 2023 and 2024 seasons to evaluate the regulatory effect of individual and combined application of wood vinegar (WV), seaweed extract (SW), and humic acid (HA) on the performance of mango (Mangifera indica L.) cv. Ewais. The results revealed that all treatments had a pronounced effect and significantly improved the total chlorophyll content (107.7 and 106.6%), leaf N (2.02 and 2.23%), P (0.38 and 0.4), and K (1.07 and 1.13%), as well as enhancing the quality of mango fruits by increasing fruit length (11.68 and 12.38 cm), fruit width (7.8 and 8.59 cm), total sugars (40 and 37.3%), and TSS (21.9 and 20.8%) while reducing the total acidity (64.3 and 69.0%) in the 2023 and 2024 seasons, respectively, compared with the control. Based on this study, the treatment of 2 L/ha seaweed + 2 L/ha humic acid + 2 L/ha wood vinegar combined had the greatest effect on enhancing Ewais mango fruit yield by up-regulating leaf mineral acquisition, antioxidant response, and sugar accumulation. This study supports the application of HA and SW in combination with WV to improve mango fruit yield and quality.

The current investigation represents of the synergistic effects of application of potassium nitrate (KNO₃) in combination with putrescine (Put) on flowering, productivity, and fruit quality on Ewais mango (Mangifera indica L.) trees during the seasons 2021/2022 and 2022/2023. The selected trees were sprayed at three different stages, including flower bud differentiation, full bloom, and beginning of the fruit set, with one of the following treatments: control, 2% KNO₃, 4% KNO₃, 50 ppm Put, 75 ppm Put, 2% KNO₃ + 50 ppm Put, 2% KNO₃ + 75 ppm Put, 4% KNO₃ + 50 ppm Put, 4% KNO₃ + 75 ppm Put. Results showed that all treatments were successful in improving the productivity of mango trees by increasing flowering terminal shoots, fruit set, fruit retention, number of fruits/tree, yield, and fruit yield increment while reducing the percentage of fruit drop, as well as improving the quality of mango fruits cv. Ewais by increasing fruit length, fruit diameter, TSS, total sugars, V.C, and total phenol and carotenoid content, but at the same time, diminishing the total acidity, as compared with control. Based on this research, the application of 4% KNO₃ in conjunction with 75 ppm Putrescine has shown the most prominent advances in enhancing Ewais tree productivity and fruit quality. The investigation successfully highlighted the synergistic effect of using KNO₃ and putrescine to improve mango fruit yield and quality.

This work conducted to investigate the effect of NAA and CPPU on fruit set and retained/panicle, accumulative and relative fruit drop %, fruit quality and yield, changes in total soluble sugars on Bacon avocado (Persea Americana Mill.) trees. The selected trees were foliar sprayed twice, at full bloom and beginning of fruit set, with one of the following treatments, water (control), NAA at 15 or 30 ppm, CPPU at 5 or 10 ppm, and their combinations. Avocado trees treated with 30 ppm NAA + 5 ppm CPPU resulted in the highest fruit set/panicle, fruit retained/panicle and significantly reduced the peak of fruit drop happen 2 weeks after fruit set. Also, 30 ppm NAA + 5 ppm CPPU and 5 ppm CPPU produced the highest fruit weight, fruit dimension and yield. All the treatments with NAA or CPPU significantly decreased the content of total soluble sugars in the leaves from the 3rd to 8th weeks after fruit set and starch from the 1st to 3rd week after fruit set. Based on this study, NAA and CPPU promoted the mobilization of carbohydrate from the leaves to the fruitlet. Hence, NAA or CPPU suppressed fruit drop in avocado by increasing the availability of carbohydrate in fruitlet and thus improved fruit retention.

This investigation was conducted to assess the regulatory effect of hydrogen peroxide (H2O2) on the growth, development,yield and fruitquality of mango cv. Ewais grown under sandy soil during 2017 and 2018 seasons.The trees received five foliarsprays ofwater (control), 5, 10, 20 and 50 mM H2O2 under field conditions. Results showed that 5mM H2O2 treatment has significantly increasedtotal chlorophyll content of the leaves, fruit set / panicle, fruit retention/panicle, peel weight, pulp/fruitpercentage and reduced fruit drop of the fruits of mango (Mangifera indica linnaeus). Using 20 mM H2O2 was reasonable in enhancing vegetative growth (number of leaves / shoot and leaf area), resulting in large fruit length and fruit width, increasing number of fruits/ tree,fruit weight and yield as compared with control. Regarding to fruit quality, it was observed that the application with 20 mM H2O2 treatment significantly improved total sugar, phenol and carotenoids content. It wasconcluded that spraying 5 and 20 mM H2O2 once a week, two times before anthesis (5th of March and 13th of March) and eight times after anthesis (from 20th of April to 15th of June)maximized the yield, productivity and fruit quality of Mango fruits under field conditions.

Avocado fruit drop after fruit set causes avocado orchards to suffer significant losses in the fruit yield, oil yield, and quality parameters of fruits. An insufficient crop load, as a result of excessive fruit drop, can reduce avocado orchard profitability. Hence, this study aimed to mitigate these problems using 1-methylcyclopropene (1-MCP), aminoethoxyvinylglycine (AVG), and N-(2-Chloro-4-pyridyl)-N′-phenyl urea (CPPU) as an environmentally friendly and cost-effective strategy to reduce accumulative fruit drop and enhance the productivity and quality of Fuerte avocado fruits. The experiment was conducted over two consecutive seasons using a randomized complete block design with eight treatments: control, 1-MCP (200 ppm), AVG (200 ppm), CPPU (5 ppm), 1-MCP + AVG, 1-MCP + CPPU, AVG + CPPU, and 1-MCP + AVG + CPPU. These treatments were applied twice, at full bloom and at the beginning of the fruit set. Avocado trees treated with 5 ppm CPPU significantly reduced accumulative fruit drop. Additionally, treatments with 1-MCP + AVG + CPPU and CPPU at 5 ppm notably improved the yield and quality of Fuerte avocado fruits by increasing fruit weight, length, width, dry matter content, total carbohydrates, crude protein, total soluble solids (TSSs), and fruit mineral content (P, K, Ca, Mg, and Fe). In contrast, treatments with 1-MCP or/and AVG had a negative impact on fruit TSSs, acidity, and carotenoid content, while producing the highest levels of chlorophyll a, b, and total chlorophyll. Treatments with CPPU alone or combined with 1-MCP and/or AVG significantly enhanced avocado oil content, with slight effects on peroxide, iodine, and saponification values. Based on the results, 1-MCP + AVG + CPPU treatment is recommended for avocado growers to enhance fruit growth, yield, quality, and oil production.