Mesbah Babalar

Selenium (Se) is a beneficial element that enhances plant antioxidant capacity, improves fruit quality, and contributes to the biofortification of horticultural crops. However, information regarding its effects on mineral nutrient balance and antioxidant metabolism in pomegranate remains limited. This study investigated the effects of foliar selenium (Se) application on fruit yield, mineral nutrient balance, antioxidant metabolism, and fruit quality of pomegranate (Punica granatum L.) cv. ‘Malas Saveh’ during the 2022 and 2023 growing seasons under orchard conditions in Iran. Trees were treated with sodium selenate at different concentrations using a randomized complete block design. In 2022, Se was applied at 0, 2, 4, and 6 mg L⁻¹, while in 2023, based on the results of the first-year screening phase, the concentration range was expanded to 0, 6, 8, and 10 mg L⁻¹ to further investigate plant responses to higher Se levels. Foliar Se application significantly increased fruit yield, fruit number, and Se accumulation in both leaves and fruits, confirming the effectiveness of Se biofortification. Selenium treatments also improved the nutritional composition of pomegranate fruits by increasing the concentrations of nitrogen (N), phosphorus (P), potassium (K), iron (Fe), and zinc (Zn), whereas manganese (Mn) concentrations declined, suggesting an antagonistic interaction between Se and Mn uptake. Significant improvements were observed in fruit quality traits, including soluble solids content, titratable acidity, vitamin C, total phenolics, anthocyanins, and antioxidant activity. The 6 mg L⁻¹ treatment in 2022 and the 8–10 mg L⁻¹ treatments in 2023 resulted in the most pronounced physiological and biochemical responses, with 10 mg L⁻¹ showing no further significant improvement for several key traits. Selenium application also enhanced the antioxidant defense system through increased activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia-lyase (PAL), and ascorbate peroxidase (APX), while reducing hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and membrane ion leakage. Principal component analysis further confirmed the strong positive association between higher Se concentrations and improved mineral and biochemical characteristics. Overall, foliar Se application effectively enhanced pomegranate productivity, nutritional quality, antioxidant capacity, and physiological performance, highlighting its potential as a sustainable agronomic practice for the production of high-quality Se-enriched fruits.

The arbuscular mycorrhizal fungi (AMF) form symbiotic, mutually beneficial relationships in the rhizosphere, and modulate phosphorus’ (P) availability to regulate plant growth, nutrient uptake, and quality. However, their roles in cut-flower species remain poorly understood. The aim of this study was to evaluate the effects of single and dual inoculation with Glomus intraradices and G. mosseae on Lisianthus (Eustoma grandiflorum) grown under three P levels (10, 20, and 40 mg kg⁻¹) in greenhouse conditions. Under intermediate P, dual-inoculated plants exhibited the greatest above-ground vigor, with increases in stem length (+31%), dry shoot weight (+67%), and highest shoot P (+54%) and N (+23%) content, compared with non-inoculated controls. Under low P, dual inoculation maximized dry root weight (+63%) and mycorrhizal colonization, whereas AMF effects diminished at high P. Principal component analysis showed that there were distinct mycorrhizal interactions (PCA2, 20.3% variance) and a close integration between vegetative growth and nutrient accumulation (PCA1, 54.3% variance). For the first time, this study demonstrates that Lisianthus exhibits a strong response to dual AMF inoculation, offering a novel strategy to enhance growth, nutrition, and ornamental quality when P fertilization is optimized. By reducing chemical fertilizer use, this dual AMF–P management offers a sustainable framework for high-quality cut-flower production.

With the world’s population and pollutants on the rise, it is crucial to find sustainable and environmentally friendly solutions that increase production efficiency. Organic horticulture is an effective strategy for creating a harmless and sustainable crop production system. Arbuscular mycorrhizal fungi (AMF) have been proposed as reliable biofertilizers for sustainable agriculture, and inoculum production is a rapidly expanding market. AMF can enhance plant nutrition and growth, but their efficacy varies depending on the plant species, inoculum type, and available P concentrations. This study evaluates the response of ornamental statice (Limonium sinuatum [L.] Mill.) to mycorrhizal inoculation (first factor) with Glomus mosseae (M1), G. intraradices (M2), or their mixture (M3), plus non-inoculation (M0), and varying available P concentrations (second factor) of 10 (control, P1), 20 (P2), and 40 (P3) mg kg⁻¹ soil in greenhouse conditions in a factorial experiment based on randomized complete block design with three replications. Root colonization, growth parameters, some ornamental traits, and the absorption of P, N, K, Ca, Zn, and Fe were measured. Root colonization was estimated as 30–65% and was reduced approximately by 32.4% with increasing P concentration in the soil. The lowest colonization percentage was recorded in P3 (45.69, 39.31, and 30.18 for M1, M2, and M3, respectively). Statice plants were positively influenced by inoculation, especially with G. mosseae in moderately available P (P2), which was also confirmed by the results of the principal component analysis. Overall, inoculated plants exhibited better nutritional status, growth, and ornamental traits than non-inoculated plants. Furthermore, mycorrhization delayed the time to the flowering of statice by 12, 7, and 9 days in M1, M2, and M3, respectively, compared to non-mycorrhizal (M0) plants. In conclusion, mycorrhizal inoculation can improve the plant nutrition, growth, and ornamental value of statice by selecting appropriate inoculum and optimal P concentrations. The results of this study suggest that mycorrhizal inoculation can be effectively used in the future to increase the quantity and quality of statice production.

The shelf life of horticultural commodities depends on pre‐ and postharvest factors, such as soil fertilization and postharvest handling. The current study aimed to evaluate fresh‐cut celery's postharvest quality as affected by the rate and type (organic and chemical) of nitrogen (N) fertilizer and postharvest treatments. Celery (‘Tall Utah’) crop was grown in a field in Karaj, Iran. The experimental design was a randomized complete block with three replications and seven preharvest (fertilizer), and five postharvest treatments. Organic fertilizers were vermicompost (VER) and bio‐organic fertilizer [farmyard and livestock manure plus Trichoderma harzianum (COM)]. Chemical fertilizers were urea (46% N) at high rate [322 kg·ha¹ N (UREA_HIGH)], optimal rate [196 kg·ha⁻¹ N (UREA_OPT)], and low rate [138 kg·ha⁻¹ N (UREA_LOW)]; ammonium nitrate [35% N (AN)] at 196 kg·ha⁻¹ N; and treatment without fertilization was used as a control. Postharvest treatments included plastic packaging (PP), hydrocooling (HC), blanching (B), and edible coating of psyllium seed mucilage (EC). After postharvest treatments, celery petioles were stored (0–2°C, 85%–90% RH) for 4 weeks and evaluated weekly for quality attributes. Organic fertilizers and UREA_LOW were the most effective treatments in reducing the changes in color, weight loss, titratable acidity (TA), pH, and total soluble solids (TSS) of fresh‐cut celery. Organic fertilizers enhanced the vitamin C content, total phenols, and antioxidant activity in celeries. As postharvest treatments, hydrocooling, plastic packaging, and blanching maintained chroma and hue values. Blanching had the greatest effect on the L* value. Hydrocooling increased celery's TA, TSS, and vitamin C content and reduced weight loss and pH during storage. Thus, celery quality was improved when grown under low or adequate N fertilization. Hydrocooling was an effective postharvest treatment for preserving fresh‐cut celery quality during storage.

Fertilizer type and rate may influence the quality of fruits and vegetables. This study compared plant growth, yield, minerals concentration, and postharvest quality of celery as affected by fertilizer type (organic and chemical) and nitrogen rate. Organic fertilizers were vermicompost (VER) and bio-organic fertilizer [compost plus Trichoderma harzianum (COM)]. Chemical fertilizers were urea (46% N) at high rate [322 kg·ha⁻¹ N (UREA_HIGH)], optimal rate [196 kg·ha⁻¹ N (UREA_OPT)], and low rate [138 kg·ha⁻¹ N (UREA_LOW)]; ammonium nitrate [35% N (AN)] at 196 kg·ha⁻¹ N, and an unfertilized treatment used as a control. Plants fertilized with UREA_HIGH had the highest plant height and yield. Yields with VER and COM were similar to those of UREA_OPT, UREA_LOW, and AN. Celery fed with organic fertilizers had reduced petiole nitrate accumulation and improved mineral content (N, P, and K). Organic fertilizer treatments were the most effective in maintaining celery quality (petiole color, weight loss, titratable acidity, pH, and total soluble solids). There was an enhancement of phytochemical compounds such as vitamin C, total phenols, and antioxidant activity in celery grown with organic fertilizers. Organic fertilizers released N more slowly into the soil, resulting in reduced plant growth and yields but increased celery's nutritional quality. Celery quality attributes with organic fertilizers were similar to those with the UREA_LOW treatment suggesting that the improved celery quality with the organic fertilizers may be attributed to reduced soil N.

Nowadays the importance of selenium for human health is widely known, but most of the plants are poor in terms of selenium storage and accumulation because of the low selenium mineralization potential of the soil. For this purpose, foliar application of different sodium selenate concentrations (0, 5, 10, 15, 20 mg/L) was used to treat the cauliflower cultivars “Clapton” and “Graffiti”. Higher yields and other related vegetative attributes were improved at 10 and 15 mg/L sodium selenate application. At a concentration of 10 mg/L sodium selenate, photosynthetic pigments, total phenolic compounds and antioxidant capacity were enhanced in both cultivars, but the “Graffiti” cultivar responded stronger than the “Clapton” cultivar. The glucosinolates were accumulated in response to selenium fortification and the highest amounts were found in the “Graffiti” cultivar at 10 mg/L. Selenium accumulated concentration-dependently and rose with higher fertilization levels. In general, foliar application of selenium at 10 mg/L led to an accumulation of secondary metabolites and also positively affected the growth and yield of florets.

Considering the importance of spice plants and their shelf life, as affected by various factors, the current study considered Summer savory plants (Satureja hortensis cv. Saturn) for evaluation under the application of different concentrations of ammonium sulfate (0, 40, 60, 80, and 100 kg/ha) as primary treatments. Based on the plant response, the control group and 100 kg/ha ammonium sulfate were selected as suitable treatments for storage experiments (i.e., storage at ambient, refrigerator, and freezer temperatures for 8 months). Based on the results, the highest percentage and yield of S. hortensis essential oil and biomass occurred in response to 100 kg ammonium sulfate, whereas the lowest amounts were observed in the control group (i.e., in the absence of ammonium sulfate). During the storage period, the essential oil content decreased, but the carvacrol content of the essential oil increased. During the different durations and conditions of storage, the stability of secondary metabolites varied. Essential oil, rosmarinic acid, and carvacrol contents maintained greater stability in plants treated with ammonium sulfate (100 kg/ha), compared with the control group during the storage period. It can be concluded that the preharvest application of ammonium sulfate on S. hortensis improved plant growth and quality indices at preharvest time, while also maintaining the stability of its active ingredients at the postharvest stage and storage time. It also led results to recommend storing Summer savory in the freezer to better preserve its secondary metabolites.