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D UE to the importance of the process of fruit waxing in Valencia orange especially for exportation, the current study aimed to evaluate the effect of bee wax, gum arabic, paraffin oil and chitosan in different concentrations as coating materials on the quality of Valencia orange fruits during cold storage at 5 • C and 90-95% relative humidity for 90 days. Chitosan at 1 or 2% and paraffin at 99% showed the lowest significant decay percentages. Moreover, chitosan at 2% showed the lowest rates of weight loss and pectin methylesterase activity, also it maintaining fruit colour brightness and hardness of fruits compared with uncoated ones. In addition to, the different applied films affected significantly respiration rate and ascorbic acid content compared with untreated ones.

This study was carried out on pomegranate fruits cv. “Wonderful” with the aim of maintaining fruit quality and water content, reducing weight loss, chilling injury and browning symptoms during cold storage at 5 °C and 90% RH for 60 d followed by simulated shelf life at 20 °C for 14 d. Coating treatments included gum arabic at 5% and 10%, paraffin at 10% and 20%, chitosan at 1% and 2%, and beeswax at 5% and 10%. All conducted coatings treatments significantly maintained fruit quality as compared to the control (uncoated ones). Chitosan at 2% significantly preserved fruit quality, firmness, visual appearance, husk colour, ascorbic acid and anthocyanin content, furthermore it reduced browning, peroxidase enzyme activity and decay incidence. Paraffin at 10% and beeswax at 10% were effective in maintaining fruit water content, in addition to the significant preservation of husk distention using paraffin at 20%, moreover, application of gum arabic at 5% maintained moderate rates of fruit respiration and total soluble solids content as compared to control.

I N RESPECT to enhancing productivity and fruit quality of Le-Conte pear, a field study was carried out during two successive seasons (2015 and 2016). The solutions of amino acids treatments including arginine (100 and 200 ppm) and tryptophan (50 and 100 ppm), in addition to salicylic acid (100 and 200 ppm) and control (water only) were sprayed on mature trees untill run off twice, first at full bloom stage and second at initial fruit set stage (after 21 days of full bloom phase). The productivity and different fruit quality parameters were assessed, as well as, measurements of total phenols, total amino acids and antioxidant capacity during fruit development stages. Applying tryptophan, arginine and salicylic acid treatments attained a valuable effect on productivity and fruit quality of pear cv. Le-Conte. Moreover, tryptophan at 100 ppm showed the highest fruit set percentage, yield, fruit weight, L/D ratio, specific gravity, lightness of flesh colour, fruit peel colour, TSS and improved total sugars, total phenols and total amino acids content of pear fruits cv. Le-Conte, whereas salicylic acid at 200 ppm showed the lowest significant fruit abscission percentages, and maintained the highest significant values of antioxidant capacity, ascorbic acid and firmness of Le-Conte pear fruits.

Maximizing food production through integrated management of vegetative and root growth is a major challenge to food security and sustainability in the face of population growth, salinity stress conditions and climatic changes specially in arid and semi-arid regions. This study was conducted to evaluate the effect of foliar application with proline (Pro) at 5 mM, calcium (Ca) at 1.5% or control supplemented with soil application of humic acid (Hc) at 0, 15 g/tree on the nutrition status, osmoregulatory mechanisms and productivity of ‘Wonderful’ pomegranate trees growing under salt stress conditions. Soil and foliar treatments were applied three times: at flowering stage (April), 2 months after fruit set (June) and at fruit maturity (August). Individual application of either Hc or Pro or Ca alleviated the adverse effects of salt stress. Moreover, supplemented soil application of Hc with Pro or Ca as foliar application increased significantly leaf Pro, total carbohydrates, N, P, Ca and K contents, as well as K/Na and Ca/Na ratio. While it significantly decreased leaf Na and Cl concentration. Furthermore, supplemented application of Hc resulted in the highest decrease in leaf Na and Cl concentrations by 94.59%, 44.79% when combined with Pro and by 51.35%, 31.28%, when combined with Ca. In addition, Hc treatment led to the highest mean fruit yield by 139.56% and 90.73%, respectively as mean of both seasons for Pro and Ca treatments, respectively. The results suggest that, exogenous Pro and Ca supplemented with Hc can mitigate salt stress in ‘Wonderful’ pomegranate through enhancing osmoprotectants accumulaton.

No abstract

Extending postharvest fruit life demand cold storage period prolongation with reasonable marketing life. In this scope, quality of Olinda orange was determined in response to arabic gum, bee wax, paraffin oil and chitosan coatings during simulated marketing life at 20 • C for 12 days after cold storage at 5 • C and 90-95% relative humidity for 90 days. All applied coatings had desirable effects on fruit quality compared with the control, where the best treatment was chitosan at 1 and 2% that were effective in maintaining ascorbic acid content compared to the uncoated ones. Chitosan coating at 2% attained the lowest significant weight loss and decay percentages. Also, it delayed changes associated with fruit aging such as colour changes, softening and pectin the methylesterase activity, in addition to valuable means of respiration rate compared to the uncoated ones. Coatings are easily applied tools that could be suitable for extending Olinda orange postharvest marketing life.

The present study aimed to extend fresh-cut guava life and retain quality using safe compounds without affecting quality or palatability. Different concentrations of ascorbic acid, citric acid and calcium lactate were used before storage at 5°C for 12 days in two successive seasons. It has been found that citric acid at 2% was the most effective in the case of fresh-cut guava compared to untreated ones in different traits under study in terms of general appearance, total soluble solids/acid ratio, colour changes, browning index and decay percentage. Citric acid and ascorbic acid treatments showed significant impacts on fresh-cut guava content of total phenols and ascorbic acid. While, calcium lactate at 2% showed the least significant values of weight loss and the highest significant firmness compared with the control.