The experiment was carried out in two consecutive seasons (2017/18 and 2018/19) on 'Sukkary' and 'Gahrawy' mango root-stocks seedlings and the purpose of the research was to investigate the effectiveness of applying Nano-silica to increase the tolerance of 'Gahrawy' and 'Sukkary' mango rootstocks. The tested treatments were tap water irrigation (TWI),TWI and spraying Nano silicon (SNSi) at 1.0g/L,Sea water irrigation (SWI) at 1750ppm, SWI at 1750ppm and SNSi, SWI at 3500ppm, and SWI at 3500ppm and SNSi. Foliar sprays of Nano-silicon were done four times;the first at the beginning of the experiment, and then three times at 45-days intervals.The effect of treatments on the behavior of the seedlings of the two rootstocks including vegetative characteristics (new leaf area, seedling height increase%, seedling stem diameter increase, root length and width, number of lateral and secondary roots and root growth coefficient), physiological parameter "Leaf pigments, total phenols and soluble carbohydrates contents",leaf mineral contents " N, P, K, Na, Ca and Mg" and Non-enzymatic antioxidants"proline content and DPPH" as well as salinity symptoms parameters were studied. Increasing levels of salinity caused a decrease in most parameters and an increase in the sodium and proline content, and salinity symptoms of the leaves. Irrigation with salty water at 1750ppm together with foliar spraying Nano-silicon enhanced leaf content of pigments, soluble carbohydrate and total phenols, Mg, N, P, K and decreasing of salinity symptoms parameters.The results confirmed that the effects of Nano-silicon on the behavior of treated seedlings differ according to the variety under salinity conditions.

Egypt to study the effects of Gum Arabic and /or calcium chloride on postharvest storage life and fruit quality of 'Maamoura' guavas during two consecutive seasons (2016 and 2017). Guava fruits were dipped for 3 min. into distilled water (control), Gum Arabic (GA, 10%), CaCl 2 (CC 1 , 2%), CC 2 (4%), GA (10%) + CC 1 (2%) and GA (10%) + CC 2 (4%). Treated and control fruits were stored at 7±1°C and 90±5% relative humidity (RH) for 24 days. The changes in physical and chemical characteristics of guava fruits were determined every eight days of cold storage. Results of this study indicated that, all postharvest treatments reduced the deterioration in physical and chemical characteristics compared to untreated fruits (control). In addition, combined treatments of 10 % of Gum Arabic with 2 or 4% of calcium chloride were superior to individual treatments. These treatments minimized the fruit weight loss and decay percentages and maximized fruit marketable percentage as well as maintained fruit firmness and visual appearance score during storage. Moreover, these applications delayed color development by retained total chlorophyll content as well as maintained fruit contents in ascorbic acid and total acidity and reduced the total soluble solids and total soluble solids/acid acidity ratio during cold storage period. Ultimately, these applications increase total phenolic and antioxidant contents; also, 706 USAMA EL-ABBASY et al. prolonged shelf life period of guava fruits at (25±2°C and 65±5% RH) after end of cold storage period (24 days) as compared to control. Conclusively, combined treatments of 10 % of Gum Arabic with 2 or 4% of calcium chloride reduced the deterioration in physical and chemical characteristics compared to untreated fruits (control).

The present study was conducted during the two seasons of 2020 and 2021 to determine the effects of pre-harvest treatment with thyme oil on grape (Vitis vinifera) Flame seedless cv. fruit quality during cold storage conditions (0±1°C and 90±5% RH).Clusters were sprayed with thyme oil at 0.2% 48 hours before harvest, while the control was sprayed by water. Fruit quality was measured at harvest time and then every 15 days of cold storage. This experiment was arranged in a factorial design with three replicates. The results in this study confirmed that grape clusters treated with thyme oil at 0.2%recorded the highest marketable percentages and visual appearance of clusters. In addition, this treatment recorded the highest berry contents of ascorbic acid and total soluble solids (TSS/TA) comparable to the control. Thus, it could be recommended to use thyme at 0.2% as safe pre-harvest treatment maintains the quality of Flame Seedless grapes during cold storage.

Persimmons (Diospyros kaki L.) cv. "Costata" were treated with hot water at 20 o C for 60 min (control) or 47 o C for 120 min or 50 o C for 60 min in the presence of sodium chloride or calcium chloride at 200 mM for each. Treated fruits were stored at 0 o C & 90-95 %RH for 8 weeks plus 5 days at 20 o C & 70-75 % RH as shelf life period. In general, marketable persimmon fruits percentage were decreased after storage. Combined treatment of hot water at 47 o C for 120 min and NaCl at 200 mM showed higher fruit dry matter content. A gradual decrease in fruit firmness was significantly observed after storage, whereas NaCl and CaCl2 treatments maintained clearly fruit firmness. SSC: acid ratio was significantly increased after storage, and the highest value was obtained by hot water at 47 o C for 120 min accompanied with CaCl2 treatments. Fruit skin color was significantly increased by 14.47 and 16.88 % after storage and the highest fruit skin color was obtained by hot water at 47 o C for 120 min. Fruit skin color might depended upon Chlorophyll a content and carotene content. Tannins content was significantly decreased after storage. Fruit treated with 47 o C for 120 min and CaCl2 resulted in low tannins content. Total chlorophyll content was significantly decreased, on the other hand, carotene content increased after period of cold storage. Treated fruit by hot water at 47 o C for 120 min showed the highest total chlorophyll.

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