Introduction

As a result of the increasing interest and desire to acquire ornamental plants for the aesthetic appearance they provide, scientific attempts have increased to solve the problems of trading these plants1,2,3. Researchers are interested in finding effective ways to improve the productivity and quality of ornamentals to extend their life spam4,5,6. For enhancing the productivity and quality, plants should receive the appropriate amounts and types of nutrients7,8,9,10,11. The inappropriate nutrients supply could expose the plants to stress hazards, suppressing growth and development12,13,14,15. In particular, nutritional stress resulting from nutrient deficiencies leads to physiological dysfunction due to oxidative damage, reducing crop yield and quality16,17,18,19.

The Solanaceae family includes the genus Brunfelsia, which provides several flowering plants20. About 50 species of shrubs and small trees can be found in Brazil. The leaves are simple and often oval21. Brunfelsia species are sold under “yesterday-today-tomorrow” and “lady of the night”; the phrase “Yesterday-Today-Tomorrow” refers to the blossom’s change from a deep purple color yesterday to a lavender color today before turning white tomorrow22. It is nocturnally performed and color-changing flowers from dark purple over mauve to white23,24. Thickets and light woodland are the typical habitats for these plants. Numerous Brunfelsia species contain toxic alkaloids and medicinal. For instance, B. grandiflora is the source of the most significant native remedies used to treat arthritis, rheumatism, and snake bites in the upper Amazon region25. According to the phytochemical analysis, steroids, flavonoids, tannins, and saponins were found in the methanol leaf extract26. However, terpenoids, anthraquinones, and cardiac glycosides were absent. DPPH activity of leaf extract and ascorbic acid standard was found. The studies found that this plant has a high level of antioxidant activity. Other Brunfelsia species including B. calycinaand B. grandiflora have been cultivated for their ornamental properties for pot plants and a common garden due to their vast blue flowers and appealing aroma21,22.

Although micronutrients are required in small quantities, their abundance is absolutely essential for plants to complete their healthy growth and produce high-quality, marketable products27,28,29. In this respect, silicon (Si) is a crucial beneficial element for high-yield cultivation of ornamentals, and other economic crops30,31,32. Si deficiency causes suboptimal growth and induces stress, reducing photosynthetic efficiency and increasing susceptibility to pests and pathogenic diseases33,34. Contrariwise, the abundance of Si promotes the growth, making plants healthier by enhancing structural integrity and facilitating key physiological processes involved in cell development and differentiation35. This is because various plant species have differing abilities to absorb Si, largely determined by the presence and efficiency of specific Si transporters in their roots36,37. Furthermore, previous studies have shown that Si plays a crucial role in the tolerance of plants to heavy metal stress, primarily through mechanisms such as metal immobilization in the soil, compartmentalization within plants, and the upregulation of antioxidant defenses38,39. Similarly, Si is critical for mitigating biotic stress, as its deposition in plant tissues creates a physical barrier that deters pests and pathogens and primes the plant’s jasmonic acid and ethylene-mediated defense pathways40,41.

Utilization of natural sources of nutrients is considered a promising practice to enhance plant growth and yield with high quality42,43,44,45. Herein, diatomite de Mozambique is a naturally occurring sedimentary rock mostly made up of the fossilized remains of freshwater diatoms. Chemically, it comprises several elements and soluble SiO2 (86–89%) available to plants. Diatomite (DM) achieves a multifaceted positive influence on plant growth, flowering, and development. It showed a positive response for number, weight, and tonnage of melon fruits to diatomite application46. Studies on various flowering plants have shown that substrate amendment with DM can lead to earlier flowering, increased flower number, and prolonged bloom duration, attributed to the overall improvement in plant health and nutrient availability47.

Potassium silicate (PS) is a highly soluble potassium and Si source. It is used in agricultural production systems primarily as Si amendment source and uses a small amount of potassium (K) to improve the quality of flowers48. K-silicate is a source of highly soluble K and Si. PS does not volatile organic compounds49. The use of PS improved vegetative parameters and led to earlier flowering, increased flower number of Tagetes patula50. Application of PS increased carotenoids, total phenols, flavonoids, and anthocyanin and K content, while decreased malondialdehyde content at all salinity levels on Cichorium intybus51.

Fertilizers prepared in nano form exhibited beneficial role for efficiently utilization of nutrients and induction of plants to be more tolerant to adverse conditions52,53,54. Herein, silica-nanoparticles (SNP) are ultra-small particles made primarily of silicon dioxide (SiO2). It significantly affects plant growth, protection of plants, and physiology. SNP can dramatically enhance the processes of water absorption and nutrient supply, positively regular photosynthesis and gas exchange, and active metabolic processes, improving the antioxidant defense system and nitrogen metabolism55,56. Further, Using SNP reduces the harmful effects of stresses such as UV radiation, salinity, drought, metal toxicity, and biotic stress57,58. Additionally, SNP can act directly as nano-fertilization, nano pesticides, and nano–herbicides59.

Si was used on bushy growing plants such as Glycyrrhiza uralensis and Glycyrrhiza inflata60, and Thunbergia erecta61. Practically, B. grandiflora have not received any studies regarding the importance of Si and its various forms in regulating metabolic processes and stimulating growth and flowering. Therefore, the current research hypothesized that the different types of Si fertilizers could influence the biochemical constituents, nutritional status, growth and flowering of plants. To prove this assumption, the effects of three Si sources at three rates each on B. grandiflora were investigated.

Materials and methods

Location and plant materials

The present research was conducted under open-field conditions at the experimental site of the Ornamental Horticulture Department, Faculty of Agriculture, Cairo University, Giza, Egypt. The experiment spanned the growing seasons from March to September in 2022 and 2023 seasons. The region experiences a Mediterranean climate characterized by arid summers and negligible precipitation. Throughout the primary growth period, the mean ambient temperature, relative humidity and mean daily solar radiation were 25.0 °C, 52.4%, 28.7 MJ m⁻² day⁻¹, respectively. The study tested the impact of different silicon sources (diatomite DM, potassium silicate, PS, and silica-nanoparticles, SNP) on biochemical constituents, nutritional status, growth and flowering of B. grandiflora. The seedlings of B. grandiflora were obtained from a commercial farm in Giza, Egypt. The seedlings were cultivated in 40 cm lengths in plastic pots (40 cm diameter). Each pot involved one seedling, and the soil mixture medium was peat moss, perlite, and compost 1:1:1 by volume (totally, 25 kg).

The applied treatments and design

The treatments were arranged in randomized complete block design with three replicates. DM was added to the soil medium a week before transplanting at three levels (2.5%, 5%, and 10%, denoted DM2.5, DM5 and DM10, respectively). PS (K2SiO3) was applied at three concentrations (1, 2, and 3 g L− 1 abbreviated as PS1, PS2 and PS3, respectively), as a foliar spray. SNP were sprayed at three concentrations (100, 200, and 300 mg L-1 coded as SNP100, SNP200 and SNP300, respectively), applied as leaf application. The control plants (CK) were treated with distilled water. For PS and SNP, the plants received the spray solutions three times until the runoff point, the first spray applied 30 days after planting, then in four-week intervals, “Tween 20” was applied at one ml L− 1 as a surfactant substance.

Specification of SNP

The Electron NRC microscopy unit was used to characterize SNP that were obtained from Sigma Cor. in the USA. According to Zafar et al. 201662, SNP are suspended in uniformly dispersed and distilled water. The specification of SNP is illustrated in Table 1; Fig. 1.

Table 1 Specification of used silica oxide nanoparticles.
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Fig. 1
figure 1

Scanning electron microscopy image of silica-nanoparticles at 100 nm.

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Assessments

Plant pigments

The photosynthetic pigments, i.e. chlorophyll a, chlorophyll b, and carotenoids were determined as explained by Saric et al. 196763 in mature leaves. According to the method of Fuleki and Francis 196864, an ethanol hydrochloric acid solution (15 ml 1.5 N HCl + 85 ml ethanol 95%) was used for extraction to determine the anthocyanin pigment in fully open flower at full bloom; four months after beginning of the treatments.

Biochemical constituents

Using fresh leaves sample, flavonoids content65 and total phenolics content66 were assessed. Total antioxidant activity (DPPH) in terms of hydrogen-donating or radical-scavenging ability, using the stable radical method described by Brand-Williams et al. 199567 was estimated.

Nutrients content

Nitrogen (N) content of dried shoots was performed by the modified Kjeldahl method68. Phosphorus (P) content was determined by the method of the ammonium molybdate in dry shoots69. The extract for determination of potassium (K) content was prepared from a digested solution in the dry shoot according to Chapman and Pratt 196170.

Application inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine Si content utilizing the microwave-assisted digestion technique71. The concentrations of magnesium (Mg) and iron (Fe) were assessed by an atomic absorption spectrophotometer with air acetylene and fuel (PyeUnicam, model SP-1900, US) as explained by Cheng and Bray 195172.

Plant growth and flowering

After 6 months from transplanting, plant height (measured from the base of plant to the tip of the plant by measuring tape), branches number plant–1, leaves number plant–1, leaf area (estimated as total leaf dry weight × disks area / disks dry weight), and flowers number plant–1 were recorded.

Statistical analysis

The results were statistically analyzed by employing COSTATV-63 program73. One way analysis of variance (ANOVA) was used to evaluate the significance by Duncan’s new multiple-range tests at p < 0.05. Pearson correlation coefficients matrix between the studied traits expressed in heat map was prepared using excel program, and COSTATV-63 program was employed to estimate the significance test at p < 0.05, p < 0.01 and p < 0.001.

Results

Plant pigments

The impacts of DM, PS and SNP on the concentration of plant pigments were significant. In this concern, data illustrated that the concentration of chlorophyll a (Fig. 2), chlorophyll b (Fig. 3), and carotenoids (Fig. 4) decreased and anthocyanin (Fig. 5) increased gradually with increasing the application rate of all silicon forms. For diatomite rates, application of DM2.5 outperformed DM10 in chlorophyll a as well as DM5 and DM10 in carotenoids in both seasons. Also, PK1 application showed greater values of chlorophyll a, chlorophyll b, and carotenoids that of PK2 or PK3 in both seasons. SNP100 increased chlorophyll a by 24.0 and 23.0%, chlorophyll b by 22.3 and 22.1%, and carotenoids by 15.2 and 14.1% in the first and second seasons, respectively, as compared to SNP300. Among the potassium sources overall, SNP100 was the potent treatment for improving all photosynthetic pigments in both seasons, significantly leveling SNP200 for chlorophyll b.

Fig. 2
figure 2

Effect of diatomite, potassium silicate and silica-nanoparticles on chlorophyll a content (mg g–1 FW) of Brunfelsia grandiflora in 2022 and 2023 seasons. DM2.5, DM5 and DM10 are application 2.5, 5 and 10% of diatomite, respectively; PS1, PS2 and PS3 are application of potassium silicate at a rate of 1, 2 and 3 g L–1, respectively; SNP100, SNP200 and SNP300 are application of silica-nanoparticles at a rate of 100, 200, and 300 mg L− 1, respectively; CK is check treatment. Values are means of 3 replicates ± SE; the same alphabets means that statistically non-significant by Duncan’s new multiple range test at p < 0.05.

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Fig. 3
figure 3

Effect of diatomite, potassium silicate and silica-nanoparticles on chlorophyll b content (mg g–1 FW) of Brunfelsia grandiflora in 2022 and 2023 seasons. DM2.5, DM5 and DM10 are application 2.5, 5 and 10% of diatomite, respectively; PS1, PS2 and PS3 are application of potassium silicate at a rate of 1, 2 and 3 g L–1, respectively; SNP100, SNP200 and SNP300 are application of silica-nanoparticles at a rate of 100, 200, and 300 mg L− 1, respectively; CK is check treatment. Values are means of 3 replicates ± SE; the same alphabets means that statistically non-significant by Duncan’s new multiple range test at p < 0.05.

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Fig. 4
figure 4

Effect of diatomite, potassium silicate and silica-nanoparticles on carotenoids content (mg g–1 FW) of Brunfelsia grandiflora in 2022 and 2023 seasons. DM2.5, DM5 and DM10 are application 2.5, 5 and 10% of diatomite, respectively; PS1, PS2 and PS3 are application of potassium silicate at a rate of 1, 2 and 3 g L–1, respectively; SNP100, SNP200 and SNP300 are application of silica-nanoparticles at a rate of 100, 200, and 300 mg L− 1, respectively; CK is check treatment. Values are means of 3 replicates ± SE; the same alphabets means that statistically non-significant by Duncan’s new multiple range test at p < 0.05.

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Fig. 5
figure 5

Effect of diatomite, potassium silicate and silica-nanoparticles on anthocyanin content (mg 100 g–1 FW) of Brunfelsia grandiflora in 2022 and 2023 seasons. DM2.5, DM5 and DM10 are application 2.5, 5 and 10% of diatomite, respectively; PS1, PS2 and PS3 are application of potassium silicate at a rate of 1, 2 and 3 g L–1, respectively; SNP100, SNP200 and SNP300 are application of silica-nanoparticles at a rate of 100, 200, and 300 mg L− 1, respectively; CK is check treatment. Values are means of 3 replicates ± SE; the same alphabets means that statistically non-significant by Duncan’s new multiple range test at p < 0.05.

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Concerning the anthocyanin pigment, SNP300 showed the highest values surpassed the other treatments in both seasons, except SNP200 in the first season. Compared to the check treatment, SNP300 increases the concentration of anthocyanin by about 4.32 and 5.2 times in 2022 and 2023 seasons, respectively.

Biochemical constituents

Remarkable influences of DM, PS, and SNP on the total flavonoids (Fig. 6), phenolics (Fig. 7), and DPPH (Fig. 8) in the leaves of Brunfelsia grandiflora were obtained in both seasons. SNP100 gave the maximum values of total flavonoids, phenolics and DPPH%, significantly equaling DM2.5, SNP200 and SNP300 for phenolics in the first season as well as DM2.5 and SNP200 for DPPH in both seasons. The increases in flavonoids, phenolics, and DPPH due to application of SNP100 were 2.81 and 2.85 folds, 1.84 and 1.97 folds and 1.25 and 1.23 folds, greater than the check treatment in the first and second seasons, respectively. It should be noted progressive decreases in all measured biochemical constituents with increasing the application rates of any potassium source. Thus, DM10, PK3 and SNP300 exhibited lower values of flavonoids, phenolics, and DPPH as compared DM2.5, PK1 and SNP100, respectively.

Fig. 6
figure 6

Effect of diatomite, potassium silicate and silica- nanoparticles on flavonoids content (mg 100 g–1 FW) of Brunfelsia grandiflora in 2022 and 2023 seasons. DM2.5, DM5 and DM10 are application 2.5, 5 and 10% of diatomite, respectively; PS1, PS2 and PS3 are application of potassium silicate at a rate of 1, 2 and 3 g L–1, respectively; SNP100, SNP200 and SNP300 are application of silica-nanoparticles at a rate of 100, 200, and 300 mg L− 1, respectively; CK is check treatment. Values are means of 3 replicates ± SE; the same alphabets means that statistically non-significant by Duncan’s new multiple range test at p < 0.05.

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Fig. 7
figure 7

Effect of diatomite, potassium silicate and silica-nanoparticles on phenolics content (mg g–1 FW) of Brunfelsia grandiflora in 2022 and 2023 seasons. DM2.5, DM5 and DM10 are application 2.5, 5 and 10% of diatomite, respectively; PS1, PS2 and PS3 are application of potassium silicate at a rate of 1, 2 and 3 g L–1, respectively; SNP100, SNP200 and SNP300 are application of silica-nanoparticles at a rate of 100, 200, and 300 mg L− 1, respectively; CK is check treatment. Values are means of 3 replicates ± SE; the same alphabets means that statistically non-significant by Duncan’s new multiple range test at p < 0.05.

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Fig. 8
figure 8

Effect of diatomite, potassium silicate and silica-nanoparticles on total antioxidant activity (DPPH) (%) of Brunfelsia grandiflora in 2022 and 2023 seasons. DM2.5, DM5 and DM10 are application 2.5, 5 and 10% of diatomite, respectively; PS1, PS2 and PS3 are application of potassium silicate at a rate of 1, 2 and 3 g L–1, respectively; SNP100, SNP200 and SNP300 are application of silica-nanoparticles at a rate of 100, 200, and 300 mg L− 1, respectively; CK is check treatment. Values are means of 3 replicates ± SE; the same alphabets means that statistically non-significant by Duncan’s new multiple range test at p < 0.05.

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Nutrients content

The rates of DM, PS, and SNP affected the concentration of N, P, K, Mg, Si and Fe in Brunfelsia grandiflora leaves. Data results in Table 2 showed that the lowest application rates of each potassium form concentrations were more effective for increasing nutrients content. Among the different forms of Si, SNP100 exhibited the highest efficiency for raising the leaf content of N, P, Mg, Si and Fe in both seasons. However, there were no significant differences between SNP100 and SNP200 or DM2.5 for Mg and SNP200 for Si in both seasons. On the other hand, PK1 was the efficient treatment for elevating K content surpassing the other treatments in both seasons.

Table 2 Effect of diatomite (DM), potassium silicate (PS), and silica-nanoparticles (SNP) on nutrients content of Brunfelsia grandiflora leaves in 2022 and 2023 seasons.
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Plant growth and flowering

According to the results of Table 3, different silicon sources (DM, PS and SNP) significantly influenced growth and flowering yield of Brunfelsia grandiflora. All Si sources and their concentrations remarkably enhanced plant height, branches number plant–1, leave number plant–1, leaf area and flowers number plant–1 comparing to the check treatment in both seasons, except PS and its rates for branches number plant–1, which equaled the check treatment in this respect. SNP100 was the most effective practice for promoting plant growth and flowering traits in both season. However, there were no significant variations between SNP100 and each of SNP200 and SNP100 for enhancing branches number plant–1 and plant leaf area in both season, in addition to SNP100 and SNP200 for leave number plant–1, in the first season.

Table 3 Effect of diatomite (DM), potassium silicate (PS), and silica-nanoparticles (SNP) on growth and flowering of Brunfelsia grandiflora in 2022 and 2023 seasons.
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Correlation analysis

The correlation coefficients matrix between different biochemical and morphological parameters of B. grandiflora are illustrated in a heat map (Fig. 9). In this respect, the correlation coefficients between each pairs of chlorophyll a, chlorophyll b, carotenoids, anthocyanin, flavonoids, phenolics, total antioxidant activity, nitrogen, phosphorus, potassium, silicon, magnesium, iron, plant height, branches number plant− 1, leaves number plant− 1, leaf area and flower number plant− 1 were estimated. All possible combinations between the studied pairs of traits showed a highly significant (p < 0.01) positive correlation, except for the pairs involved potassium with all other traits. In this concern, there was significant (p < 0.05) and negative correlation between potassium and anthocyanin. Also, there were no significant correlation relationships between potassium and each of chlorophyll a, chlorophyll b, carotenoids, flavonoids, phenolics, total antioxidant activity, nitrogen, phosphorus, silicon, magnesium, iron, plant height, branches number plant− 1, leaves number plant− 1, leaf area and flower number plant− 1. Furthermore, the correlation between phenolics and leaf area was not significant.

Fig. 9
figure 9

Heat map illustrates the correlation analysis between different pairs of Brunfelsia grandiflora traits. Cha: chlorophyll a, Chb: chlorophyll b, Caro: carotenoids, Anth: anthocyanin, Flav: flavonoids, Phen: phenolics, DPPH: total antioxidant activity, N: nitrogen, P: phosphorus, K: potassium, Si: silicon, Mg: magnesium, Fe: iron, PH: plant height, BNP: branches number plant− 1, LNP: leaves number plant− 1, LA: leaf area and FNP: flower number plant− 1. ns: not significant, *: significant at P < 0.05, **: significant at P < 0.01 and ***: significant at P < 0.001.

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Discussion

Plant growth, development, and flowering productivity are critical for economic ornamental trees and shrubs. Si application showed positive effects on the growth and flowering of the ornamental plants74. Si fertilizers can enhance nutrient uptake by maximizing soil fertility and plant water absorption, while improving soil physical and chemical characteristics46. Additionally, Si is an abundant, practical, and non-toxic element involved in various plant functions75. Physiologically, Si can enhance photosynthesis at the expense of reduced transpiration, which will help with carbon build-up and nitrogen metabolism. Better leaf architecture and increased capacity for light absorption are made possible by Si absorption and subsequent formation of a double silicate layer on the leaf epidermis76.

The current research study was performed to examine the influence of different silicon sources (DM, PS, and SNP) on growth, flower yield as well as the chemical composition of B. grandiflora. Photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoids) and anthocyanin significantly were increased by application different silicon treatments. In this regard, DM, PS, and SNP enhanced chlorophyll a, chlorophyll b, and carotenoids concentrations as well as anthocyanin comparing to the check treatment. Treating plants with DM at 30% gave the greatest increase in chlorophyll a, chlorophyll b, and carotenoids in Moringa oleifera77. Foliar application of nano silicon at 75 mg L− 1 increased chlorophyll index (46%), stomatal conductance (34.6%), and relative water content (46.3%) in Lathyrus sativus78.

Interestingly, we observed a strong correlation between the morphological and flowering production and the secondary metabolite accumulation obtained in the leaves. For this reason, abundance of Si is essential to enhance the levels of total phenolics and flavonoids, increase the antioxidant activity, and stimulate the carbohydrates transportation to different sections of plant organs, leading to improved growth and flower production79. SNP at 300 mg L− 1 as foliar application increased total sugars, total phenolics, and total free amino acids80. As well, treating marigold seedlings with silicon enhanced carbohydrate contents and total flavonoids81.

The findings also depicted that the contents of N, P, K, Si, Mg and Fe, in response to different applications of Si, were improved comparable with control. Uses of DM improved NPK% on Zea mays plants compared to other treatments and the control82. The treatment of SNP in Polianthes tuberosa increased leaf P and Si contents74. Furthermore, treating chrysanthemum plants with PS significantly increased the content of K, P, Mg, Fe, S and Zn83. In another study, it was observed that spraying of Si on marigold seedlings enhanced N, P, and protein81. Si has a function in preventing an imbalance of nutrients during the growth and production of plants84. The higher nutrient content resulting from the use of Si as a fertilizer can also be attributed to the fact that it reduces the leaching of minerals such as N and K away from the root medium85.

Concerning the growth and flowering, it has been reported that DM increases morphological and flowering parameters in Antirrhinum majus plants86. In another study, Zaman et al. 202287 revealed that applying DM increased the morphological yield of Cicer arietinum. Obklin et al. 202388 illustrated that treated plants with DM at the rate of 5 t ha− 1 had a significant effect on plant height and dry weight of maize plants. It has been documented that Si increases the endogenous gibberellin formation in seedlings leading to stem elongation89. In addition, PS foliar application at 12 ml L− 1 on Rosmarinus officinalls showed increases in growth characteristics compared to control90. Moreover, using of PS at 1 to 3 g L− 1 as foliar application enhanced the growth and flowering traits of Antirrhinum majus91. Additionally, it should not be neglected that PS fertilizer contains K which has a stimulatory effect and crucial function in plant growth92,93. As for SNP, their application at 1000 mg L− 1 in Rosa chinensis had improvements of growth traits80. SNP spraying at 200 mg L− 1 and 400 mg L− 1 enhanced leaf fresh weight, root and bulblet dry weight, and root valium in tuberose plants74. In addition, using foliar application of silica nanoparticles boosted leaf area and relative chlorophyll content while improved all morphological and flowering properties of carnation plants94.

For economic ornamental plants, flower number is a critical parameter for beautiful aspects. More significant flowers number are essential, particularly in B. grandiflora because they are commonly used in landscape gardening and easily identified by the color change (violet to white) of their flowers and fragrance, and difficult to be distinguished22. In the current study, the flower numbers were improved significantly by the application of different silicon sources (DM, PS, and SNP) compared to the check treatment (Fig. 10). Since DM is typified by minute sized-particle with high permeability and porosity95, the improvements in growth and flowering of DM-treated plants are expected. Previous studies on Polianthes tuberosa74, Antirrhinum majus86,91, Rosa chinensis80, Tagetes erecta L96. , and Lilium orientalis97 cited an increase in flower yield by treating with Si as a result of increase its content in the leaves. Such findings could be ascribed to the Si’s potential impact on sugar metabolism, which could raise the concentrations of soluble carbohydrates in PS-sprayed leaves98. As for Si in nano from, SNP with diameters of 5–20 nm can readily penetrate the cell wall and reach the plasma membrane. They may enter through stomatal openings or at the base of trichomes, allowing foliar-applied particles to move into various tissues. Following their accumulation and translocation, SNP induce alterations in multiple cellular and physiological functions of the plant99. In rice, SNP have been shown to enter the xylem via active transport pathways100.

Fig. 10
figure 10

The best concentration of different silicon sources on morphology and flowering of Brunfelsia grandiflora, (A) check treatment, (B) diatomite 2.5%, (C) potassium silicate 1 g L–1, and (D) silica-nanoparticles 100 mg L− 1.

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Conclusions

Supplying Brunfelsia grandiflora plants with the appropriate form of silicon is so crucial for high flower yield and quality. In this connection, modification of plant pigments, nutrient contentment and biological molecules via application of silicon achieved substantial enhancements in growth and flowering. Herein, the tested various silicon sources, especially silica-nanoparticles and diatomite improved photosynthetic and anthocyanin pigments, total contents of phenolics, flavonoids and antioxidant activity, hence, morphological and floral traits were improved. Eventually, in Brunfelsia grandiflora the cultivation system, farmers have distinctive options involving silica-nanoparticles at 100 mg L− 1 (if available) or diatomite at 2.5% to be applied to modify the physiological and nutritional status for high yield and quality flowers.