Chrysanthemum is one of the most consumed and most valuable cut flowers worldwide. In this study, the effectiveness of three concentrations of either thyme oil (300,400 and 500 mg/l) or clove oil (150,250 and 500 mg/l) as additives in holding the postharvest solutions of chrysanthemum ‘‘Arctic Queen White’’ cut flowers were investigated. The experiments were carried out as a completely randomized design in three replicates. Many postharvest characteristics have been evaluated, such as the vase life of cut flowers, diameters of head flowers and stem, dry matter of flowers, total vase water uptake, total loss of water, relative fresh weight. Additionally, the chlorophyll contents, total sugar, and bacterial counts were determined. The results showed that the longest vase life of cut chrysanthemum was 36.50, 33.40 days, and 35.88, 31.33 days by addition of either the thyme oil (500 mg/l) or clove oil (250 mg/l) in holding solution as compared with distilled water (18.09 and 17.22 days) in both seasons. The highest total vase water uptake and relative fresh weight were (225.00, 211.05 g/flower/day) and (79.89, 70.37 %) of cut chrysanthemum treated with 500 mg/l thyme oil in both seasons. Whereas the lowest total water loss in the two seasons was 155.11 and 156.60 g/flower/day was found with 400 mg/l thyme oil. The greatest chlorophyll a, b, carotenoids, and total sugar contents obtained from treated cut chrysanthemum with 500 mg/l thyme oil (6.89, 2.37, 5.99 mg/g, and 0.88 mg/gm D.W, respectively). Furthermore, the treatment of cut flowers with selected oils has significantly decreased the bacterial growth compared to the control. Whereas the minimum bacterial activities were <1 C.F.U/ml with cut chrysanthemum fortified with 500 mg/l thyme and clove oils. Moreover, the superlative treatments with thyme (500 mg/l) and clove (250 mg/l) showed a prime state of xylem vessels comparable with the control.thus, the usage (addition) of thyme and clove oils as a natural preservative in holding solutions instead of chemicals would be of great economic and environmental impact (Values).

Purpose: Medicinal plants show a relevant importance in human life and health. The use of natural substances in crop management is not only significant for the plant healthy growth and yield, but also for obtaining safe products. The study aimed to examine the effect of seaweed extract (SW) as a natural source of nutrition and salicylic acid (SA) on plant health, physiology and essential oil profile of French marigold (Tagetes patula L.). Methods: Three levels of salicylic acid, SA50, SA100 and SA200, (50, 100, and 200 mg L^− 1) and three levels of seaweed extract, SW2, SW4 and SW6 (2.0, 4.0, and 6.0 ml L^− 1), in comparison with control treatment (tap water) were applied as foliar sprayings. The seven treatments were arranged in randomized complete block design and were replicated thrice in two growing seasons (2020 and 2021). Results: Findings pointed out that SA200 increased plant height, branches number plant^− 1, stem diameter, leaf area, leaves number plant^− 1, plant fresh weight, and plant dry weight by 32.9, 112.2, 59.2, 34.4, 44.3, 33.0 and 56.9% (averages of the two seasons), respectively, compared to the control treatment (tap water). SW6 increased carotenoids content by 34.8 and 46.4% in 2020 and 2021 seasons, respectively. Salicylic acid at the rate of 200 mg L^− 1 along seaweed extract at 6 ml L^− 1 gave the highest values of total sugars and free amino acids. SA200 alone recorded the maximal value of peroxidase activity surpassing the other treatments. SW6 possessed the greatest essential oil content in both seasons, statistically equaling SA200 in the first season. Huge variations in essential oil profile were recorded under the tested trial treatments. Conclusion: It could be concluded that salicylic acid and seaweed extract foliar application unveiled their involvement in diverse physiological and developmental responses; pigment formation, enzyme activities, flower induction, nutrient uptake, essential oil metabolism, and overall plant growth and development. It is recommended to use the highest concentrations of the tested substances (SA at 200 mg L^− 1 or SW at 6.0 ml L^− 1) for achieving distinctive improvements in physiological responses of French marigold plant.

Although goldenrod (Solidago canadensis) is considered an invasive plant in many countries, it is a global cut-flower species. In addition, demand for goldenrod has increased significantly in recent years. Thus, the present study aimed to evaluate the response of Solidago canadensis cv. Tara to brassinosteroids (BRs) at levels of 0.10⁻³, 10⁻⁶, and 10⁻⁸ M, and chitosan at 0, 100, 150, and 200 mg/L as a foliar application to increase the quality and quantity of production, and its polyphenolic compounds. Moreover, antibacterial activity and genetic polymorphism for both untreated and the optimally treated goldenrod were investigated. The results showed that the highest mean of growth characteristics was found when plants were treated with BRs at 10⁻⁸ M, whereas the longer vase life was obtained using 200 mg/L chitosan. Furthermore, higher pigment values, N, P, K, and total phenolic content, antioxidant capacity, chlorogenic acid, and rutin content were detected on plants treated with 200 mg/L chitosan. In addition, foliar application with 200 mg/L chitosan caused higher antibacterial activity among the control and BRs. The optimal treatment of BR at 10⁻⁸ M (89%) showed a low genetic similarity, based on sequence-related amplified polymorphism (SRAP) analysis, comparable with the control and 200 mg/L chitosan. BR at 10⁻⁸ M and 200 mg/L chitosan showed a significant enhancement of growth parameters. As a result, it can be concluded that goldenrod, as a herb extract, shows significant promise as a natural preservative in pharmaceutical, food, and cosmetic products.

Nanoparticles present innovative solutions for postharvest applications, allowing for the development of compounds that effectively extend the vase life of cut flowers by reducing ethylene production and preventing bacterial growth. As a leading choice among cut flowers, Tulips encounter common issues such as neck bending and a limited display life, which can severely impact their marketability. This experiment aims to evaluate the effectiveness of nano chitosan (CHS-NPs) at 3.5 and 7.0 mg L ^− 1 , nano copper (Cu-NPs) at 15 and 30 mg L ^− 1 , and Cymbopogon flexuosus essential oil (LG) at 150 and 300 mg L ^− 1 as innovative, eco-friendly solutions for improving the quality and extending the vase life of cut tulip flowers. The findings reveal that CHS-NPs and Cu-NPs significantly prolong the vase life of cut tulip flowers, with optimal concentrations determined to be 30 mg L ^− 1 Cu-NPs (15.56 and 16.33 days) and 7.5 mg L ^− 1 CHS-NPs (13.01 and 14.00 days), respectively. The greatest RFW% was 110.97 and 112.30% on day 7 in both seasons of cut tulip flowers treated with 30 mg L ^− 1 Cu-NPs. These treatments enhance water uptake and relative fresh weight (RFW%), effectively inhibit microbial growth at the stem base, and prevent bacterial blockages in the xylem for up to seven days. Moreover, they substantially increase chlorophyll levels, total soluble carbohydrates, and proteins while decreasing hydrogen peroxide (H ₂ O ₂ ) production, thereby enhancing membrane stability. At the same time, the highest SOD and CAT activity were 1.77 and 1.92 Units mg ^− 1 protein and 2.82 and 2.98 Units mg ^− 1 protein with the 30 mg L ^− 1 Cu-NPs in the first and second seasons, respectively. In conclusion, CHS-NPs at 7.5 mg L ^− 1 and Cu-NPs at 30 mg L ^− 1 significantly enhance the vase life of cut tulips by improving water balance and antioxidant activity, with Cu-NPs demonstrating better effectiveness. Adopting Cu-NPs at the recommended concentration should be prioritized in the tulip floral industry.

Purpose: The loss of flower quality after harvesting is a major concern in the floriculture industry. Because cut flower solutions are quickly contaminated with microbes, causing flower damage, they must be modified to enhance and extend the life of the vase. Methods: Eco-friendly preservative solutions were examined to investigate the efficiency of natural essential oils of eucalyptus, neem and rosemary at concentrations of 200 and 400 mg L^–1 each on the biological, physiological, and anatomical traits and vase life of solidago (Solidago canadensis) cut flower. Results: Using different essential oils at both concentrations showed significant impact on cut flower longevity. The maximum vase life was obtained by solidago placed in a preservative solution containing 400 mg L^–1 of neem essential oil, which enhanced water uptake and relative fresh weight and reduced both water loss and microbial count when compared to other treatments and control treatment. The chlorophyll, total phenol, flavonoid, and carotenoid content of the spikes increased in solidago cut-flower placed in a preservative solution containing neem essential oil 400 mg L⁻¹. Results also showed decreased malondialdehyde (MDA), hydrogen peroxide (H₂O₂) levels and total antioxidant activity (DPPH radical-scavenging activity) with the application of all natural oils supply. Anatomically, cut flowers that treated with essential oils had considerably clearer vessels and significantly fewer bacteria than untreated cut flowers. Conclusion: The higher concentration of different essential oils gave better results than the lower concentration. These results suggest that for the floriculture industry, natural phyto-oils provide a clear viable method to extend the vase life of solidago cut flowers. Thus, neem oil at a concentration of 400 mg L^–1 added to a preservative solution is considered the most promising practice for prolonging the vase life and maintaining high quality of Solidago.

Recently, several countries have been using silicon (Si) fertilization in agricultural plants. The application of Si has a beneficial role on plant growth via affecting the cellular metabolites and physiological events. However, there are little findings that interpret the impact of different Si sources on physiological and agronomical traits of Brunfelsia grandiflora. Along the two seasons of 2022 and 2023, this study examined the impact of different Si sources (diatomite (DM), which comprises several elements and soluble SiO₂ (86–89%), potassium silicate K₂O₅Si₂ (PS), and silica-nanoparticles (SNP)) at different rates on biochemical constituents, nutritional status, growth and flowering of B. grandiflora. In addition to check treatment (no Si application), three levels of each of DM (2.5%, 5%, and 10%; DM2.5, DM5, and DM10, respectively), PS (1, 2 and 3 g L^–1; PS1, PS2 and PS3, respectively), and SNP (100, 200, and 300 mg L^− 1; SNP100, SNP200 and SNP300, respectively) were sprayed three times at four-week intervals, initiating 30 days after planting. The estimated data showed that DM and SNP as sources of Si had remarkable potential for ameliorating photosynthetic pigments, anthocyanin, nutrients content and secondary metabolites, hence the morphological and flowering traits of B. grandiflora. SNP had a positive impact comparable with DM or PS. Foliar application of SNP100 exhibited the maximum increases in plant pigments concentration with high healthy status and flower production. However, the supplementation of DM as a natural Si fertilizer should not be neglected where DM2.5 had acceptable growth and flowering potential compared to PS and untreated plants. Si supplementation, particularly with SNP and DM, improved morphological and floral traits by boosting pigment content (photosynthetic and anthocyanin), increasing phenolics and flavonoids level, and enhancing overall antioxidant capacity. The growers are advised to insert Si in fertilization programs of B. grandiflora to obtain high flower yield and quality. According to the availability, application of silica-nanoparticles at 100 mg L^− 1 or diatomite 2.5% are costless and good practices to nourish B. grandiflora plants.