Salt stress significantly impacts plant morphological structure and physiological processes, resulting in decreased plant growth. Salicylic acid (SA) is a key signal molecule that protects plants from the negative impacts of salinity. Under natural conditions, the pomegranate plant generally exhibits salt-tolerant characteristics. The objective of this study was to elucidate the salt-tolerance level of pomegranate (Punica granatum L. cv. Wonderful) and the effect of the regulating strategy of SA foliar spray on growth, morphological structure, and physiological processes. SA levels were 0, 0.25, 0.50, and 1 mM in the presence of salinity levels of 10, 35, and 70 mM NaCl, respectively. Vegetative growth indices, including stem cross-sectional area, leaf area, and total dry weight, were lowered by salinity treatments. However, SA applications greatly improved morphological characteristics and plant growth under salt stress. The effects of salinity were effectively reversed by SA treatment at 1 mM compared to control and other treatments. Interestingly, SA applications enhanced the chlorophyll, total phenolic, carbohydrate, and proline contents of leaves while decreasing electrolyte leakage (EL), Na, and Cl levels. Moreover, the foliar SA treatments enhanced the nutrient content in the leaves and increased the activities of peroxidase (POD) and catalase (CAT), with a decrease in malondialdehyde (MDA) content. This study suggests that the alleviation of the salinity stress by SA may be due to the activation of the antioxidant enzymatic mechanism and decrease in the lipid peroxidation of the pomegranate plant.

The synergistic effect of dipping in 55 °C for 5 min of hot water (HW) and 1% chitosan coating during the storage of mango at 13 ± 0.5 °C and 85%–90% relative humidity for 28 days was investigated. The combined treatment significantly suppressed the fruit decay percentage compared with both the single treatment and the control. In addition, the specific activities of key plant defense-related enzymes, including peroxidase (POD) and catalase (CAT), markedly increased. The increase occurred in the pulp of the fruits treated with the combined treatment compared to those treated with HW or chitosan alone. While the control fruits showed the lowest values, the combination of pre-storage HW treatment and chitosan coating maintained higher values of flesh hue angle (h°), vitamin C content, membrane stability index (MSI) percentage, as well as lower weight loss compared with the untreated mango fruits. The combined treatment and chitosan treatment alone delayed fruit ripening by keeping fruit firmness, lessening the continuous increase of total soluble solids (TSS), and slowing the decrease in titratable acidity (TA). The results showed that the combined application of HW treatment and chitosan coating can be used as an effective strategy to suppress postharvest decay and improve the quality of mango fruits.

Peaches are grown in many Egyptian orchards for local and global fresh market sales. The interior fruit tissue breakdown (IFTB), often resulting in decayed peaches, is a severe problem during marketing. Therefore, to minimize FTB of peaches, in this study, gum arabic (GA) and polyvinylpyrrolidone (PVP) were mixed with different concentrations of salicylic acid (SA) (0, 1, and 2 mM) and were applied as edible coating to extend the shelf life of peach fruits. Mature peaches were selected and harvested when peaches reached total soluble solid content (SSC: 8.5%) and fruit firmness of about 47 N. Fruits were coated and stored at room temperature (26 ± 1 °C and air humidity 51 ± 1%) for 10 days during two seasons: 2020 and 2021. Fruit coated with GA/PVP-SA 2 mM showed a significant (p < 0.05) inhibition in degrading enzyme activities (CWDEs), such as lipoxygenase (LOX), cellulase (CEL), and pectinase (PT), compared to uncoated and coated fruits during the shelf-life period. Hence, cell wall compartments were maintained. Consequently, there was a reduction in browning symptoms in fruits by inhibiting polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) activities. Thus, the fruit skin browning index showed almost no symptoms. The lipid peroxidation process and ionic permeability declined as well. The result suggests that, by applying GA/PVP-SA 2 mM as an edible coating, fruit tissue breakdown can be minimized, and the shelf life of peach can be extended up to 10 days without symptoms of tissue breakdown.

The postharvest quality of ‘Zaghloul’ date palm cultivar was investigated to study the effects of ozone on weight loss rate, electrolyte leakage (EL), total soluble solids (TSS), titratable acidity (TA), ascorbic acid, total phenol content and antioxidant activity at harvest and during cold storage at 0 ± 1°C for up to 30 days. Moreover, the study aimed to elucidate the efficiency of ozone application on controlling microbial growth. The fruits were exposed to 150 ppb ozone (O3) by using ozone generator (biofresh OZ80, UK).The results indicated that ozone application reduced the yeasts and molds and mesophilic aerobic bacteria compared to control. Ozone treated fruits had higher weight loss than control but the differences were not significant. However, Ozone treated fruit showed lower total soluble solid, electrolyte leakage, and rutab% compared to non-ozone treated ones. Ozone treated fruits had higher ascorbic acid and total phenol contents as well as antioxidant activity, while did not significantly affect fruit titratable acidity. Thus, ozone application could be an effective strategy for maintaining post-harvest quality of dates and provide a longer storage life.

The present investigation was conducted during 2014 and 2015 growing seasons in order to study the effects different drought stress levels in particular; 100%, 50% and 25% of the soil field capacity (FC) as well as the effects of arbuscular mycorrhizal (AM) inoculation on morphological and physiological performance and drought resistance of pomegranate seedlings. Drought stress decreased arbuscular mycorrhizal (AM) colonization. In both the AM and non AM, growth rate, leaf area, trunk cross sectional area and total dry weight decreased with increasing drought stress levels. AM colonization significantly stimulated plant growth indices and biomass production regardless of water status. Increasing drought stress levels tended to increase the proline accumulation, while the chlorophyll content, leaf total carbohydrates, and catalase activity (CAT) decreased. By contrast, AM colonization increased chlorophyll content, proline, total carbohydrates and CAT activity. A gradual decrease in leaf water potential (Ψ) and relative water content was evident with increasing drought stress levels. However, the seedlings inoculated with AM fungus had significantly higher leaf water potential (- 1.5MPa) compared to the non-inoculated seedlings (- 2.0MPa).

The present investigation was conducted during the 2018 and 2019 growing seasons on one-year-old persimmon seedlings cv. “Costata” grafted on “Seedy” and “Tarabouls” rootstocks in order to improve its survival percent and orchard perfoprmance. The Seedlings were treated with K-NAA or IBA either by dipping at 3000 mg l-1 for 5 seconds or soaking at 500 mg l-1 for 24 hours. Obtained results generally showed significant increase in vegetative growth, root biomass and leaf chlorophyll and mineral content by all K-NAA and IBA applications compared to the water treated ones. A highest values of sprouting buds percent (during April, June and August), average shoots number, trunk cross-sectional area, leaf area and canopy volume were recorded with the K-NAA soaking at 500 mg l-1for 24 h. Leaf chlorophyll content was highest with K-NAA and IBA soaking in the first season, while K-NAA soaking at 500 mg l-1 for 24 h gave the highest values of leaf N, P, K, Fe, Mn and Zn in both seasons. Also, the K-NAA soaking or dipping applications recorded the highest values of average shoot length, increment percnts of shoot length and stem diameter and highest seedlings survival in both seasons. The K-NAA soaking at 500 mg l-1 for 24 h gave the highest significant values of root biomass in the first season. Results also showed that seedlings on “Seedy” rootstock surpassed the ones on “Tarabouls” rootstock in all vegetative growth parameters and root biomass, but contained lower leaf N, P, Mn and Zn.