Background: At present, agricultural production management techniques focus on greater commitment to environmental sustainability. As such, this study was carried out during two successive seasons (2018 and 2019) to investigate the impact of two natural bio-stimulant substances: humic acid (H) and milagro (M) on vegetative growth and nutritional status of Nonpareil almond young trees grown in Experimental Research Station of National Research Centre, Nubaria, El Behera governorate, Egypt. Three-year-old uniform trees were treated at the beginning of growth season by soil application of humic acid (H) and foliar spray of milagro (M) bio-stimulant. There were ten treatments as follows: control (untreated seedlings),10 g humic acid plus 10 ml/l milagro, 20 g humic acid plus 10 ml/l milagro, 30 g humic acid plus 10 ml/l milagro,10 g humic acid plus 20 ml/l milagro, 20 g humic acid plus 20 ml/ l milagro, 30 g humic acid plus 20 ml/l milagro, 10 g humic acid plus 30 ml/l milagro, 20 g humic acid plus 30 ml/l milagro, and 30 g humic acid plus 30 ml/l milagro. Results: The results showed that different treatments improved the vegetative growth of seedlings, stem length, diameter, number of branches and leaves, leaf area, leaf fresh and dry weight, and specific leaf dry weight as well as leaf chlorophylls and minerals content comparing with untreated young trees. Conclusions: Soil application of 30 g humic acid along with 30 ml/l milagro per young tree as foliar spray was the promising treatment as a new fertilization technique that is non-chemical, low-cost, and environmentally safe for improving growth and nutritional status of Nonpareil almond young trees under Nubaria conditions.

Micro-propagation of olive provides the possibility of mass production true to type plants with appropriate attributes in short period of time, compared to conventional methods. Micropropagation of olive requires optimization of protocols adapted to specific cultivars requirements. This experiment was carried out during 2020 and 2021 seasons in tissue culture laboratory of Pomology Department, Faculty of Agriculture, Cairo University in order to evaluate the potential effects of Nano silver at 0, 5, 10 and 20 mg L -1 to improve sprouting percentage and shoot growth of Picual olive cv. The effect of nutrient media composition (MS modified, OM and OM modified) and cytokinins (BAP and Zeatin) on multiplication rate and shoot growth were examined. IBA and NAA (2 and 4 mg L -1 ) were examined during rooting stage. The obtained results cleared that silver Nanoparticles (AgNPs) at 5 mg L -1 recorded the highest percentage of bud sprouting, shoot length, number of shoots/explant and number of leaves/ shoot. Olive medium (OM) recorded the highest shoot length, number of shoots/explant and number of leaves/ shoot compared with OM modified and MS modified media. Also, Zeatin at 4 mg L -1 recorded the highest shoot growth parameters during in vitro multiplication stage. During in vitro rooting stage, both the type and concentration of auxins have a significant influence on number of roots, root length and rooting % of Picual olive cultivar. In conclusion, it is recommended that very low concentrations of Nano silver particles to be used in plants tissue culture on olive media (OM) supplemented with Zeatin at 4mg L -1 .

Background Plum fruit has a short shelf life with a rapid deterioration in quality after harvest. The main aim of this study was to evaluate the effect of preharvest treatments by moringa leaf extract (MLE), boric acid (B), and chelated calcium (Ca EDTA) on Hollywood plum fruit quality attributes bioactive compounds and antioxidant activity during cold storage. Plum trees were sprayed twice: at full bloom stage and 1 month later with T1, 5% MLE + 1% B + 2% Ca EDTA; T2, 5% MLE + 2% B + 3% Ca EDTA; T3, 10% MLE + 1% B + 2% Ca EDTA; T4, 10% MLE + 2% B + 3% Ca EDTA; and T5, water only as control. At maturity stage, fruits were harvested and stored at 0 ± 1 °C and RH 85–90% for 8 weeks. Results At the end of storage, all studied treatments exhibited significantly higher sensory quality: firmness, color, soluble solid content:titratable acidity ratio, total anthocyanin content, total flavonoids content, total phenolic content, and antioxidant activity than control. Conclusions It could be concluded that preharvest treatment with moringa leaf extract, boric acid, and chelated calcium could be a safe and eco-friendly to improve and maintain plum quality attributes and especially their content of antioxidant compounds during cold storage periods.

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