Pomegranate trees quality under drought conditions using potassium silicate, nanosilver, and selenium spray with valorization of peels as fungicide extracts

The current study was performed on 8 years old "Succary" pomegranate cultivar (Punica granatum L.) during the 2019 and 2020 seasons. One hundred pomegranate trees were chosen and sprayed three times at the beginning of flowering, full bloom, and 1 month later with the following treatments: water as control, 0.025, 0.05 and 0.1 mg/L Se; 5 mL/L, 7.5 and 10 mL/L Ag NPs, and 0.5, 1 and 2 mg/L K2Si2O5. The results showed that spraying of SE, Ag NPs, and K2Si2O5 ameliorated the shoot length, diameter, leaf chlorophyll content, set of fruiting percentage, and fruit yield per tree and hectare compared to control through studying seasons. Moreover, they improved the fruit weight, length, and diameter, as well as total soluble solids, total, reduced, and non-reduced sugars percent, while they lessened the juice acidity percentage compared to control. The most obvious results were noticed with Se at 0.1 mg/L, Ag NPs at 10 mL/L, and K2Si2O5 at 2 mg/L in both experimental seasons over the other applied treatments. By HPLC analysis, peel extracts showed the presence of several bioactive compounds of catechol, syringic acid, p-coumaric acid, benzoic acid, caffeic acid, pyrogallol, gallic acid, ferulic acid, salicylic acid, cinnamic acid, and ellagic acid. The extracts applied to Melia azedarach wood showed promising antifungal activity against Rhizoctonia solani and were considered wood-biofingicides.


Materials and methods
Experimental design. This study is complied with relevant institutional, national, and international guidelines and legislation. This study does not contain any studies with human participants or animals performed by any of the authors, where Pomegranate cv. Succary trees at the age of 8 years planted at 4 × 5 m at a private orchard at Rashid, Alexandria Governorate, Egypt through 2019 and 2020 in a sandy soil were irrigated with dripping system. The collection of Pomegranate specimens has been done under the permission from the private land owner, at Rashid, Alexandria Governorate, Egypt. Physiochemical analysis for the soil of the experiment was listed in Table 1 50 .
One hundred pomegranate trees were chosen and were similar in their growth and size as possible to apply the following treatments: Control (water only), Selenium (Se) (Alfa aesar®, Alfa Aesar, headquartered in Ward Hill, Massachusetts, United States) at 0.025, 0.05 and 0.1 mg/L; silver nanoparticles (Ag NPs) at 5, 7.5 and 10 mL/L; Potassium silicate (K 2 Si 2 O 5 ) (Alfa aesar®) at 0.5, 1, and 2 mg/L. The chosen trees were foliar treated at the first of flowering, full bloom and 1 month later and were received the same horticultural treatments applied at the orchard. The aforementioned treatments were ordered in Randomized Complete Block Design, where each one of them contained ten replicates/trees. The influence of the aforementioned treatments was evaluated by measuring their impacts on the following: Vegetative parameters. Four main vegetative shoots around the trees from each side were labelled at the start of the vegetative season, and their tallness and diameter were assessed first in April and second at October. Leaf chlorophyll content in fresh leaves was assessed by chlorophyll meter (SPAD-502; Konica Minolta, Osaka, Japan) and the results were expressed in SPAD units. Fruit set percentage was assessed according to this equation: Fruit drop percentage was estimated by accounting dropping fruits number from the middle of June till fruit harvesting time conditions of the experiment, then expressed as a percentage according to this formula: Fruit cracking percent was measured according to the following equation: Fruit cracking(%) = Number of cracking fruits total number of fruits on tree × 100 Preparation of pomegranate extracts. Peels from treated fruit with Se, Ag NPs, and K 2 Si 2 O 5 in April 2020 were air-dried at room temperature for 2 weeks. The dried peels from pomegranate fruits were ground to a fine powder using a small laboratory mill. About 50 g from each of the dried powder peels were extracted by the soaking method 56 with 100 mL of acetone solvent (99%) with stirring for 6 h at room temperature. After the extraction process was finished, the extract filtered through a cotton plug and then with Whatman No. 1 filter paper. The filtered extract was concentrated by evaporating the acetone solvent to have the dried peel extracts. To prepare the concentrations, the extracts were dissolved in dimethyl sulfoxide (10% DMSO), and the concentrations levels of 2%, 4%, and 6% were obtained 57 .
HPLC analysis of phenolic compounds. The phenolic compounds from the acetone extracts of each of the pomegranate peels were identified by HPLC (Agilent 1100) was composed of binary LC pump, a UV/Vis detector, and C18 column (125 mm × 4.60 mm, 5 µm particle size). Chromatograms were obtained and analyzed using the Agilent ChemStation. The separation and identification conditions ca be found in the previous work 58 .
Antifungal property of wood treated with extracts. Wood

Results and discussions
Vegetative and fruit parameters. Table 2 showed that length and thickness of shoots, leaf chlorophyll, were greatly enhanced by spraying Se, Ag NP S and K 2 Si 2 O 5 with respect to control. Besides, the same measured vegetative growth parameters were greatly improved particularly with Se at 0.1 mg/L, Ag NPs at 10 mL/L and K 2 Si 2 O 5 at 2 mg/L compared with the other applied concentrations, and K 2 Si 2 O 5 was the superior treatment in both studying seasons. These results are in parallel with the reported results of a lot of authors, who mentioned that spraying Se is capable of raising the resistance of plants to biotic and abiotic exertion 64,65 , and lessen the oxidation stress in chloroplast 66 , thus it can enhance the development of plants 67 . Selenium plays a crucial role in physiological processes and in improving the growth parameters of orange 68 . reported that the foliar spraying of "Washington" navel orange by selenium at 0, 20, 40, 80 and 160 ppm improved significantly the shoot number, length, secondary shoots, leaf number per shoot and leaf surface area compared with control 69 . Small dose of Se can induces the growth of plant, increases the process of photosynthesis and helps in the balance of the necessary nutrient elements 70 . Foliar application of orange trees by Se at 0, 20, 40, 80 and 160 ppm raised the growth, yield, fruit quality attributes, leaf mineral content and enzymes activity, and the concentration of 40 ppm was the best results compared with the rest applied treatments 69 . The application of selenium at five different concentrations at 0, 10, 20, 40, and 80 mg L −1 on four different olive cultivars: "San Felice", "Canino", "Frantoio", and "Moraiolo". It was noticed that Se concentration between 10 and 40 mg L −1 increased fresh and dry weight of the explants and shoot lengths 71 .
With the same trend, it was reported by many authors that Ag NPs had a good influence on growth, rootshoot ratio, and root prolongation [72][73][74][75] . Spraying of saffron corms with Ag NPs at 20-60 mg/L increased significantly the number of roots, dry weight of leaves 76 , and also the growth of plants, the surface area, length of roots and shoots as well as chlorophyll content 77 . Photosynthesis, chlorophyll content, fresh weight, root and shoot length, as well as developing of seedlings in Brassica juncea seedlings were enhanced by Ag NPs compared with control 78 . Spraying cucumber with Ag NPs raised the number of leaves per plant and plant height 79 . Ag NPs raised leaf area, shoots and growth of plants 24,26,80,81 , content of pigments 27 , and the accumulation of biomass 25 and improved shoot induction and proliferation. Ag NPs-foliar spraying increased plant growth attributes in terms of length of shoot, and root, and leaf area as well as leaf total chlorophyll 16 . The foliar spraying of onion with Ag NPs at 20 ppm increased plant height, total leaf and leaf content from total chlorophyll 15 . Additionally, the foliar application of Ag NPs at 10, 12.5, and 15 mL/L. positively increased the diameter of shoots, leaf surface area, leaf total chlorophyll in leaves in 'Florida prince' peach cultivar 82 .
Silicon plays a great role in increasing photosynthetic rate, cell division, number of pigments, the absorption and transferring of water, and root growth as well as the tolerance against biotic and abiotic exertions 29,33,[83][84][85][86] . Spraying 250 ppm K 2 Si 2 O 5 on 'Flame seedless' grapevines increased the leaf area and the length of main shoot as well as leaf total chlorophyll as compared to control in the two seasons 41 . Moreover, the exogenous application of K 2 Si 2 O 5 at 0.05-0.1% on 'Grandnaine' banana increased greatly pseudostem height, and girth, leaf surface area, green leaves number 38 . Spraying K 2 Si 2 O 5 at 0.05, 0.1 and 0.2% on 'Keitte' mango trees at the start of growth, www.nature.com/scientificreports/ just after fruit setting and 1 month later increased shoot length, leaf number per shoot, leaf area and total chlorophylls 87 . The spraying of orange cv. Olinda Valencia with K 2 Si 2 O 5 increased shoot length, and diameter, leaf number per shoot, leaf area surface, as well as the height, volume and diameter of tree with respect with untreated plants 88 . Potassium silicate plays an important role in minimizing the production of ethylene and chlorophyll degeneration 43 . Spraying orange trees with K 2 Si 2 O 5 at 0.1, 0.2 and 0.3% 89 , induced an obvious improving of shoot length and thickness, leaf area, leaf nutrient, pigment contents and total chlorophyll and the utilization of 0.2% was the superior treatment compared with control and the rest applied treatments. Table 3 clearly showed that fruit set percentage as well as fruit number were statistically enhanced by the spray of Se, Ag NPs and K 2 Si 2 O 5 , while they lessened obviously the fruit drop proportion with the respect of untreated trees. Besides, spraying 0.1 mg/L Se, 10 mL/L Ag NPs and 2 mg/L K 2 Si 2 O 5, extremely increased fruit set percentage and fruit number, and minimized the fruit drop percentage compared with the other applied treatments or control in the two seasons. Spraying of Se, Ag NPs and K 2 Si 2 O 5 reduced statistically the fruit cracking and sunburn proportion, while they increased significantly the fruit yield (Table 4). Additionally, the most positive impact on the forementioned parameters were increased by the foliar application of Se at 0.1 mg/L, Ag NPs at 10 mL/L and K 2 Si 2 O 5 at 2 mg/L with the respect of the other treatments. The most clear results were accompanied with the foliar application of K 2 Si 2 O 5 at 2 mg/L compared with the rest applied treatments and control in both experimental seasons.
These results are in the same trend with the prior results 4,5 , where the application of selenium increased efficiently the yield in horticultural crops. Besides, it was found that Se raised the yield in "Valencia" orange 68 , 'Zaghlol' date palm 90 and in 'Starking Delicious' apple cultivar 91 . Additionally, Se acts as an anti-senescent and has the ability to improve growth and developing of plants 92,93 . Furthermore, it was found that the foliar spraying Table 3. Influence of the foliar spraying of Se, Ag NP S and K 2 Si 2 O 5 on the percentages of fruit set, and fruit drop as well as fruit number of "Succary" pomegranate cultivar 2019 and 2020 seasons. Means not sharing the same letter(s) within each column are significantly different according to LSD at 0.05 level of significance. Spraying Ag ions reduced the abscission of flowers and the flowering buds in ' Alstroemeria' 94 , and in orchid 95 . Ag NP from 20 to 60 ppm raised the yield in Borage 96 . The foliar applications of Ag NPs on cucumber increased number and weight of fruit per plant 79 . Ag NP exogenous spraying at 60 ppm increased the leaf area, length of shoots and roots of Phaseolus vulgaris and Zea mays 77 . It was shown that NPs significantly raised the uptaking and transferring of NPK, thus consequently they could improve the plant growth, chlorophyll content, and grain yield 80 . Spray of Onion with 20 mg/L Ag NPs raised the yield 15 , and with 10, 12.5 and 15 mL/L, pollen viability and flowers percentages of peach cv. Florida prince were improved, and thus the fruit yield 82 .
Silicon plays an important role in rising photosynthesis rate, cell division, pigments in the plants, absorption of water, tolerance of biotic and abiotic stresses and thus the final yield 33,85 . Exogenous spraying of K 2 Si 2 O 5 at 250 ppm raised number of clusters per vine and therefore increased the final obtained yield compared with control in the two experimental seasons 41 . The exogenous spraying of 'Grandnaine' banana with 0.05 and 0.1% K 2 Si 2 O 5 raised obviously the weight of bunch and hands, number of hands per bunch, number of fingers, thus consequently it improved the final yield compared with control 38 . Spraying K 2 Si 2 O 5 at 0.05, 0.1 and 0.2% on 'Keitte' mango trees at the start of growth, just after fruit setting and 1 month later increased the percentages of initial fruit setting, fruit retention, fruit weight and subsequently the yield 87 . Spraying orange cv. Olinda Valencia with K 2 Si 2 O 5 boosted the fruit yield and 2% was the eminent treatment in the two seasons 88 . Spraying loquat trees with K 2 Si 2 O 5 at 1 or 2% improved the percentages of fruit retention, fruit weight, number of fruits per cluster and thus the final yield 43 . K 2 Si 2 O 5 sprayed at 5000 ppm enhanced the fruit weight, depleted the fruit cracking with improving the yield in 'Wonderful' 97 and 'Manfalouty' pomegranates 98 with the respect of untreated trees. Spraying of "Washington Navel" orange trees (by 0.1, 0.2 and 0.3% K 2 Si 2 O 5 enhanced clearly number of fruits per tree, fruit weight, thus consequently the fruit yield 89 . The premier one was K 2 Si 2 O 5 at 0.2% that gave an increment in the average yield than the control. Weight, volume, length, and diameter of fruit, were clearly enhanced by spraying of Se at 0.025, 0.05 and 0.1 mg/L, Ag NPs at 5, 7.5 or 10 mL/L and K 2 Si 2 O 5 at 0.5, 1 and 2 mg/L in comparison to control ( Table 5). The influence of Se, Ag NPs and K 2 Si 2 O 5 was boosted in parallel with the raising of the applied concentrations, where the significant results were obtained with 0.1 mg/L Se, 10 mL/L Ag NPs and 2 mg/L K 2 Si 2 O 5 . The upper treatment was found with the application of K 2 Si 2 O 5 compared with the rest applied treatment.
Fruit firmness, grain weight and juice volume were notably improved by the foliar spraying of Se at 0.025, 0.05 and 0.1 mg/L, Ag NPs at 5, 7.5 or 10 mL/L and K 2 Si 2 O 5 at 0.5, 1 and 2 mg/L ( Table 6). The aforementioned fruit characteristics were improved parallel to the raising of the applied concentrations from Se, Ag NPs and K 2 Si 2 O 5. The significant increments were obtained with the spraying of K 2 Si 2 O 5 as compared to the rest applied treatments in both experimental seasons.
These results are in agreement with the former results on peach 99 , on pear 100 , and on pear-jujube 101 , where Se has a crucial role in increasing the maintenance of flesh firmness and delaying fruit ripening. Selenium works as an anti-senescent and helps maintain the structure and function of the cell in plants 92,93 . Besides, treating "Zaghlol" date palm with Se increased the fruit weight 90 . Spraying Citrus Sinensis trees with Se at 0, 20, 40, 80 and 160 ppm improved markedly pulp weight and thickness, as well as fruit diameter, height and volume and 40 ppm was the predominant one 69 . Spraying apple trees with Se at 0.5, 1, and 1.5 mg/L twice during the enlargement fruit period increased the flesh fruit firmness 91 .
Ag NPs enlarge weight, diameter and length of fruit of cucumber 79 , 20 ppm Ag NPs on onion increased its bulb weight 15 , and peach trees with 10, 12.5, and 15 mL/L. Ag NP on peach improved greatly fruit weight, volume, length, and diameter, flesh weight as well as fruit firmness 82 . www.nature.com/scientificreports/ These results are in the same trend with previous results 102 , where treating grapevines cv. Flame seedless with K 2 Si 2 O 5 at 250 ppm increased weight of berry and cluster over control. Spraying potassium silicate increased the fruit firmness in "Amal" apricot cultivar 103 , "Anna" apple 104 and orange 105 as compared to untreated trees. Additionally, the exogenous sprinkle of K 2 Si 2 O 5 on banana cv. Grandnaine at 0.05-0.1% increased weight, length, and diameter of finger 38 . The foliar application of K 2 Si 2 O 5 at 0.05, 0.1 and 0.2% on 'Keitte' mango trees at the start of growth, just after fruit setting and 1 month later increased fruit length, width, firmness, and the percentage of seeds and peel 87 . The average of fruit weight, volume, dimensions, shape index and juice weight as well as fruit firmness of sprayed orange trees cvs. Washington with potassium silicate were increased 106 and Olinda Valencia 88 . With the same trend, the foliar spray of loquat trees with K 2 Si 2 O 5 at 1 or 2% raised the fruit weight, size, length, diameter and firmness, pulp percentage, thickness, and weight 43 . Moreover, K 2 Si 2 O 5 sprayed at 5000 ppm increased the fruit weight in pomegranate cvs. Wonderful 97 and Manfalouty 98 compared with untreated trees. The exogenous sprinkle of K 2 Si 2 O 5 at 0.1, 0.2 and 0.3% boosted the fruit weight, diameters, height, volume and Fruit peel thickness in orange cv. Washington Navel 89 .
The percent of fruit total soluble solids, TSS/acidity ratio, and fruit content from vitamin C were significantly boosted by the foliar application of Se at and, Ag NPs and K 2 Si 2 O 5 , while they reduced that fruit acidity percentage compared to control ( Table 7). The best results were statistically resulted from the spraying of K 2 Si 2 O 5 followed by Ag NPs at Ag NPs at 10 mL/L.
The proportions of total, reduced and non-reduced sugars, fruit content from anthocyanin were markedly raised by the external application of Se at 0.025, 0.05 and 0.1 mg/L, Ag NPs at 5, 7.5 or 10 mL/L and K 2 Si 2 O 5 at 0.5, 1 and 2 mg/L, with the respect of control ( Table 8). The highest increments in the previous measurements were accompanying to the foliar spraying of Se at 0.1 mg/L, Ag NPs at 10 mL/L and K 2 Si 2 O 5 at 1 or 2 mg/L over the other applied treatments and control. Additionally, the current results exhibited that K 2 Si 2 O 5 at 2 mg/L was Table 6. Influence of the foliar spraying of Se, Ag NPS and K 2 Si 2 O 5 on fruit firmness, grain weight and juice volume in "Succary" pomegranate fruit during 2019 and 2020 seasons. Means not sharing the same letter(s) within each column are significantly different according to LSD at 0.05 level of significance.   16,77 . The foliar applications of Ag NPs on cucumber increased TSS of fruit 79 . Sprinkle of Ag NPs on sunflower at 50 mL/L increased the leaf content from carbohydrate as compared to control 16 . The external application of Ag NPs at 20 ppm on onion increased total soluble solids 15 . Ag NPs improved greatly the percentages of TSS, TSS/acid ratio, total, reduced and non-reduced sugars as well as fruit content from anthocyanin, while they reduced the fruit acidity percentage 82 .
The exogenous sprinkle of grapevines cv. Flame seedless with 250 ppm potassium silicate increased statistically the percentages of TSS, as well as total and reducing sugars compared with control 41 . Spraying of potassium silicate on 'Grandnaine' banana at 0.05 to 0.1% improved the percentages of TSS and total sugars, while it reduced the fruit acidity percentage compared to control 38 . Silicon application improved fruit content from total soluble solids, TSS /acid ratio and vitamin C in "Anna" apple 104 , and in orange cv. Olinda Valencia 88 . The external application of K 2 Si 2 O 5 at 0.05, 0.1 and 0.2% on 'Keitte' mango trees at the start of growth, just after fruit setting and 1 month later increased the percentages of TSS, total, reducing, non-reducing, vitamin C content, while it reduced the fruit acidity 87 . Treating of loquat trees with K 2 Si 2 O 5 at 1 or 2% improved the percentages of TSS, TSS/ acid ratio, total sugars, vitamin C, while they lessened total fruit acidity proportion 43 . The external application of K 2 Si 2 O 5 at 5000 ppm boosted the fruit chemical characteristics in terms of ascorbic acid, anthocyanin and total soluble solids percentages, while reduced the fruit acidity in pomegranate cvs. Wonderful 97 and Manfalouty 98 compared with untreated trees. External application of "Washington Navel" orange trees with and K 2 Si 2 O 5 at 0.2 and 0.3% boosted markedly the fruit content from the percentages of SSC, reducing, total, non-reduced, Vitamin C content, SSC/acidity ratio, while reduced the total fruit acidity % 89 .
The results listed in Table 9 showed that the foliar application of Se, Ag NPs and K 2 Si 2 O 5 improved significantly the leaf mineral composition from N, P, and K macronutrients compared with the control during the two seasons. Additionally, the foliar application of 0.1 mg/L Se, 10 mL/L Ag NPs and 1 and 2 mg/L K 2 Si 2 O 5 exhibited the high percentages from N, P and K compared with the other applied treatments in both experimental seasons. Moreover, the superior treatment was the application of K 2 Si 2 O 5 at 2 mg/L. Low dose of Se can help in the balance of the necessary nutrient elements in the plants 5,70 . Spraying Citrus Sinensis with Se at 20, 40, 80 and 160 ppm improved obviously potassium, nitrogen and phosphorus concentration in the leaves with the respect of control and 40 ppm was the supreme one 69 .The application of nano fertilizers can help the translocation process of nutrients to the desired parts of plant 108 . Nano fertilizers greatly enhanced the uptake of NPK nutrients, which play an important role in increasing the growth, chlorophyll content and yield of wheat 80 .
Spraying 'grapevines with K 2 Si 2 O 5 at 250 ppm four times boosted leaf mineral composition from N, P and K in the two seasons rather than control 41 .External application of K 2 Si 2 O 5 at 0.05, 0.1 and 0.2% on 'Keitte' mango trees at the start of growth, after fruit setting and 1 month later raised the percent's leaf P, K and Mg 87 . External application of orange with K 2 Si 2 O 5 raised leaf N, P, and K, contents and K 2 Si 2 O 5 at 4.0% the premier for leaf N and K content 88 .
Antifungal activity. Figure 1 shows the visual observation of the antifungal activity of wood-treated with peels' acetone extracts from fruits of pomegranate as sprayed with numerous nanoparticles. Antifungal action of wood-treated with numerous acetone extracts from peels of pomegranate fruits as treated with variant nano- Table 8. Influence of the foliar spraying of Se, Ag NPS and K 2 Si 2 O 5 on fruit content from total, reduced and non-reduced sugars, and anthocyanin of pomegranate cv. Succary during 2019 and 2020 seasons. Means not sharing the same letter(s) within each column are significantly different at 0.05 level of significance. www.nature.com/scientificreports/    Table 11 demonstrate that the greatest abundant concentration of catechol was found in acetone extract from peels of fruits treated with 0.05 mg/L Se (12.30 µg/mL) and 5 mL/L Ag NP (8.22 µg/mL) but not noticed in other treatments. Syringic acid was found with high quantity in acetone extract peels of fruits treated with 7.5 mL/L Ag NP (13.30 µg/mL), 0.025 mg/L Se (11.26 µg/mL) and 0.1 mg/L Se (8.66 µg/mL). The highest amount of p-coumaric acid was observed in acetone extract from peels of fruits treated with 0.1 mg/L Se (9.56 µg/mL), 7.5 mL/L Ag NP (9.55 µg/mL), 0.05 mg/L Se (9.22 µg/mL) and in untreated (6.77 µg/mL). Benzoic acid was identified only in acetone extracts of peels from fruits treated with 5 mL/L Ag NP (9.66 µg/mL), 10 mL/L Ag NP (5.47 µg/mL), 0.5 mg/L Si (5.98 µg/mL) and in untreated fruits (5.98 µg/mL). The highest concentration of caffeic acid was seen in acetone extract from peels of fruits treated with 0.025 mg/L Se (12.06 µg/mL), 2 mg/L K 2 Si 2 O 5 (10.77 µg/mL) and 10 mL/L Ag NP (7.88 µg/mL). Pyrogallol Table 10. Antifungal activity of acetone extracts from peels of pomegranate fruits collected from trees sprayed with different nanomaterials against the growth of R. solani. www.nature.com/scientificreports/ compound showed the highest abundant concentrations in acetone extract from peels of fruits collected from trees sprayed with 0.1 mg/L Se (12.39 µg/mL) and 1 mg/L K 2 Si 2 O 5 (12.69 µg/mL) and in untreated (10.23 µg/ mL). Gallic acid with high amount was observed in acetone extract from peels of fruits from trees treated with 10 mL/L Ag NP (12.44 µg/mL) and in untreated (9.44 µg/mL). The highest amount of ferulic acid was identified in acetone extract from peels of fruits treated with 0.025 mg/L Se (13.09 µg/mL), 0.1 mg/L K 2 Si 2 O 5 (11.97 µg/ mL) and 7.5 mg/L Ag NP (6.12 µg/mL). Salicylic acid was found at high quantity in acetone extracts from peels of fruits treated with 0.5 mg/L K 2 Si 2 O 5 (12.44 µg/mL) and 0.05 mg/L Se (11.45 µg/mL). Cinnamic acid showed the highest amount in acetone extracts from fruit peels of trees treated with 5 mL/L Ag NP (14.33 µg/mL) and untreated trees (19.36 µg/mL). The highest concentration of ellagic acid was observed in acetone extracts from peels of treated trees with 0.05 mg/L Se (18.33 µg/mL) and 0.1 mg/L Se (7.69 µg/mL). The full HPLC chromatograms of the isolated and identified phenolic compounds are shown in Fig. 2. Therefore, the bioactivities of acetone treated-wood are linked to the existence of bioactive phenolic compounds. Peel extract has been reported to contain more phenolics than seed or pulp extracts 46,109 . The predominant compounds were gallic acid, ellagic acid, quercetin, caffeic acid, p-coumaric acid, and vanillic acid were found in peel extract 110,111 . Gallic and ellagic acids were presented in the methanolic extract of pomegranate peel 112 . Peel extracts demonstrated power antifungal activity against Aspergillus niger and Trichoderma reesei 113 . Peel extract showed markedly antifungal activity against A. parasiticus and A. parasiticus 114 . Peel extract noticed high activity against A. parasiticus and no activity against A. flavus 115 . The development levels of Alternaria alternata, Stemphylium botryosum, and Fusarium spp. growth rates were significantly inhibited by the peel extracts 116 that were negatively linked to the rates of punicalagins, the major ellagitannins in pomegranate peels. F. oxysporum mycelia development was prevented by 62% (propanol extract) to 78% (water extract) of peel extracts 117 . The current study is in harmony with our previous works related to wood-biofungicides. Acetone extracts of Acer saccharum var. saccharum inner and outer bark in combination with citric acid when applied to wood showed strong bioactivities against Trichoderma viride, Fusarium subglutinans, and A. niger 56 , where, phenolic compounds p-hydroxy benzoic acid, gallic acid, salicylic acid, vanillin and o-coumaric acid, and ferulic acid were identified by HPLC. Wood samples of M. azedarach wood treated with flower aqueous extract of Acacia saligna showed good antifungal activity against Penicillium chrysogenum and moderate activity against Fusarium culmorum and Rhizoctonia solani 59 , and the HPLC showed the presence of benzoic acid, caffeine, and o-coumaric acid as most abundant compounds. F. culmorum and R. solani mycelial growths were inhibited significantly as wood treated with 3% methanolic extract of Musa paradisiaca peel that showed phenolic compounds of ellagic acid and gallic acid 118 .

Conclusion
Spraying Se, Ag NPs and K 2 Si 2 O 5 raised the shoot length , diameter, leaf chlorophyll, fruit set proportion, and fruit yield, fruit weight, length and diameter, total soluble solids, total, reduced and non-reduced sugars, while they minimized the juice acidity percent with the respect to control during our study. Fruit cracking and fruit sunburn were lessened markedly by the application of Se, Ag NPs and K 2 Si 2 O 5 with respect to control. The application of 0.1 Se mg/L, 10 ml/L Ag NPs and 2 mg/L K 2 Si 2 O 5 was more effective than 0.025 or 0.05 mg/L Se, 5 or 7.5 mL/L Ag NPs and 0.5 or 1 mg/L K 2 Si 2 O 5 in improving the developing performance, yield and yielding components through studying times. The supreme treatments, which achieved the best results, was the application of 2 mg/L K 2 Si 2 O 5 over the other applied treatments during our study seasons. Additionally, the extracts from fruit peels identified several bioactive phenolic compounds and the extracts observed good wood-biofungicide.

Data availability
All data generated or analyzed during this study are included in this published article. Table 11. HPLC analysis of phenolic compounds in acetone extract of pomegranate fruit peels treated with different treatments. *ND not detected.  www.nature.com/scientificreports/