Microsoft Word - p9-20 Agricultural Science; Vol. 7, No. 1; 2025 ISSN 2690-5396 E-ISSN 2690-4799 https://doi.org/10.30560/as.v7n1p9 9 Published by IDEAS SPREAD Effect of Different Nutrient Solutions and Multiple Bio-Stimulant Dosages on Yield and Growth of Capsicum Annuum in Soilless System Edouard Tabet1, Lynn Samia1, Suzy Rouphael1, Chadi Hosri2, Elie Awad3 & Dalida Darazy4 1 Faculty of Agriculture, Department of Plant Production, Lebanese University, Dekwaneh, Lebanon 2 Faculty of Agriculture, Department of Animal Production, Lebanese University, Dekwaneh, Lebanon 3 Faculty of Agriculture, Department of Basic Sciences, Lebanese University, Dekwaneh, Lebanon 4 Faculty of Agriculture, Department of Plant Protection, Lebanese University, Dekwaneh, Lebanon Correspondence: Edouard Tabet, Faculty of Agriculture, Department of Plant Production, Lebanese University, Dekwaneh, Lebanon. Tel: 61-365-5178. E-mail: Received: January 21, 2025 Accepted: February 10, 2025 Online Published: February 11, 2025 Abstract This study evaluates the impact of two nutrient solutions (F1 and F2) and varying dosages of the plant bio-stimulant Atomes F.D.Inc. Bio Sciences PHP®, (D1 = 50 mL, D2 = 100 mL, D3 = 150 mL, and D0 = control) on the growth and yield of Capsicum annuum in a hydroponic system. The results demonstrate that F2 significantly enhanced overall plant growth and yield compared to F1, with notable increases in fruit count (25±10 vs. 24±9), average fruit width (8.31±1.02 cm vs. 8.03±1.00 cm), average fruit length (11.79±1.19 cm vs. 11.55±0.89 cm), and total yield weight (2.85±0.89 kg vs. 2.68±0.91 kg). Plants treated with D3 exhibited the highest yield, with a total fruit weight of 3.90 kg, compared to 1.69 kg in the control group (D0). D3-treated plants also produced an average of 37 fruits, while D0 produced only 13. Conversely, D0-treated plants resulted in larger individual fruit sizes, with an average fruit width of 8.98 cm and a length of 13.20 cm, compared to 7.89 cm and 10.91 cm in D3-treated plants. These findings underscore the importance of precise nutrient management and bio-stimulant applications in optimizing hydroponic bell pepper production. Future research should focus on long-term economic feasibility and large-scale implementation strategies. Keywords: Capsicum annuum, hydroponics, nutrient solutions, bio-stimulants, soilless agriculture 1. Introduction Capsicum annuum L., widely recognized as bell pepper, is a crop of global significance due to its high nutritional value and economic importance. In addition to its prominent role in culinary applications, bell peppers are rich in antioxidants and vitamins, offering numerous health benefits (Swamy, 2023; Kelley et al., 2009). Global demand for Capsicum annuum has led to an expansion in its cultivation area, with a harvested area of 2.055 million hectares reported in 2021 (FAOSTAT, 2023). Hydroponics has emerged as an efficient and sustainable cultivation method, allowing precise control of nutrient supply, reduced water usage, and year-round production (Sardare & Admane, 2013). However, optimizing hydroponic systems for Capsicum annuum requires the integration of suitable nutrient solutions and bio-stimulants. Bio-stimulants, such as plant growth-promoting rhizobacteria (PGPR) and other natural extracts, enhance nutrient absorption, root biomass, and crop yield (Rouphael & Colla, 2020). Despite its advantages, hydroponics adoption in Lebanon faces barriers such as technical challenges and financial constraints (Tabet et al., 2020). This study investigates the effects of different nutrient formulations and bio-stimulant dosages on the growth and productivity of Capsicum annuum, providing actionable insights into optimizing hydroponic pepper cultivation. 2. Materials and Methods 2.1 Description of the Work The experiment took place between April and August 2024 at the Lebanese University's Agricultural Research and Training Center (CRFA) in Ghazir, Keserwan District, situated 550 meters above sea level. The greenhouse covered 224 m² and contained 48 substrate bags, each planted with three Capsicum annuum seedlings. The plants underwent seven harvests, with the first on July 2, 2024, and the final on August 13, 2024. as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 10 Published by IDEAS SPREAD 2.2 Meteorological Data According to an online resource (Timeanddate.com), the temperature during the production phases ranged from 15 to 34 degrees Celsius, with an average maximum humidity of 66 to 72%. 2.3 Variety of Bell Pepper, Type of Substrate and Bio-Stimulant The experiment used Sweet Pepper Sultan F1, a bell pepper variety from the United States, for its robust development and significant green fruits. It was recommended to plant after the final frost in April, ensuring nighttime temperatures exceed 13 degrees Celsius. Three-plant coco peat bags were purchased from Hawa Agri, and BioSciences PHP®, a rhizobacterial-based bio-stimulant from Atomes F.D. Inc. Company, was used to promote root growth and overall plant growth. 2.4 Substrate Bags and Planting The coco peat bags were submerged in water for over 24 hours to expand the substrate. After being removed, they were placed in a greenhouse to install an irrigation system, complete with spaghetti and main pipes, and bell pepper seedlings were planted in the bags. 2.5 Fertigation The fertigation of Capsicum annuum was executed using a Dosatron at the irrigation station of the center, with drippers at a 12 l/h flow rate. Fertilizers were made independently and weighed using a precision balance. Fertilizers were mixed with consideration of element compatibility to prevent precipitation and ensure nutrient availability. One tank contained calcium nitrate and iron chelate, while the other housed phosphates and sulfates. The production cycle included two phases: vegetative development (0-6 weeks) and blooming and fruiting (6-16 weeks). The ingredients for the two fertilization recipes are listed in Table 1. Table 1. Components of F1 and F2 nutrient recipes during the two phases of the production cycle in ppm Components of fertilization formulas Phase I 0-6 weeks Phase II 6 – 12+ weeks F1 F2 F1 F2 Nitrogen (N) 237.50 224.00 376.18 189.00 Phosphorus (P) 140.70 47.00 125.00 47.00 Potassium (K) 216.60 281.00 434.00 351.00 Calcium (Ca) 57.00 212.00 171.00 190.00 Magnesium (Mg) 39.72 65.00 75.85 60.00 Iron (Fe) 12.53 2.00 13.95 2.00 Manganese (Mn) 4.97 0.55 4.46 0.55 Zinc (Zn) 1.02 0.33 5.84 0.33 Boron (B) 2.44 0.28 2.20 0.28 Copper (Cu) 0.13 0.05 0.85 0.05 Molybdenum (Mo) 0.11 0.05 0.10 0.05 2.6 Bio-Stimulant The bio-stimulant was administered in three doses: 50 mL, 100 mL, and 150 mL, applied to two bags using the same fertilization recipe within the same block. It was applied once a week for the first month and twice every two weeks for the rest of the experiment. The bio-stimulant was mixed in water and rested for 30 minutes before application. The solution was manually administered to the seedlings, ensuring uniform distribution of the bio- stimulant to each seedling. as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 11 Published by IDEAS SPREAD 2.7 Experimental Design The experiment involved 48 bags divided into two groups based on fertilization recipes (F1 and F2) and dosages (D1, D2, D3, and D0). The setup followed a split-split plot design with three repetitions. Each block had two fertilization recipes and three dosages, with two bags acting as the control group (D0). The harvest period was also considered as a sub-factor. The temperature recorded from the first day of harvest to the last day is shown in the graph. Daily measurements of electrical conductivity (EC) and pH were taken throughout the experiment, as shown in table 2. 0 5 10 15 20 25 30 35 2- Ju l- 24 9- Ju l- 24 16 -J ul -2 4 23 -J ul -2 4 30 -J ul -2 4 6- A ug -2 4 13 -A ug -2 4 T em pe ra tu re in ° C Harvest Dates Average High Average Low Graph 1. Forecast chart showing average high and low temperatures from the 1st harvest till the 7th harvest 48 Bags Block 1 F1 (6 bags) 2 bags D1 2 bags D2 2 bags D3 2 bags D0 F2 (6 bags) 2 bags D3 2 bags D0 2 bags D2 2 bags D1 Block 2 F1 (6 bags) 2 bags D0 2 bags D3 2 bags D1 2 bags D2 F2 (6 bags) 2 bags D1 2 bags D2 2 bags D3 2 bags D0 Block 3 F1 (6 bags) 2 bags D3 2 bags D0 2 bags D2 2 bags D1 F2 (6 bags) 2 bags D0 2 bags D3 2 bags D1 2 bags D2 Figure 1.The experimental design used as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 12 Published by IDEAS SPREAD Table 2. Daily measurements of EC and pH Fertilization recipe Production phase Ec pH F1 Phase I (0-6 weeks) 1.69 6.5 Phase II (6-12+ weeks) 2.2 6.76 F2 Phase I (0-6 weeks) 2.33 6.54 Phase II (6-12+ weeks) 2.49 6.99 2.8 Measured Parameters The parameters were categorized into two groups: those related to fruits at each harvest and those related to the plant at the end of the experiment. Data collection included number of fruits, average fruit length (cm) and width (cm), total yield weight (kg), dry root weight (g) and stem length (cm). Measurements were taken using a measuring tape, and yield and roots were weighed using a precision balance. 2.9 Statistical Analysis The study used General Linear Model and Sigma stat software to analyze data. Three-way ANOVA with repeated measures was applied to compare the effects of Harvesting, Fertilization, and Dosage on Capsicum annuum fruits, considering a split-split plot design. The analysis included relative parameters like fruit number, relative average width (cm), relative average length (cm), and total yield weight (kg). Two-way RM ANOVA was used to compare fertilization and dosage effects on dry root weight (g) and stem length (cm). The Duncan test was used to differentiate significant differences between treatments at 0.05%. 3. Results and Discussion 3.1 Effect of Variations in Harvests on Parameters Taken at Each Harvest Graph 2. Effect of variations in harvests on number of fruits, average width and average length of fruits (cm), and total yield weight (kg) In graph 2, results showed that the first harvest H1 yielded the best results regarding number of fruits, average width and average length of fruits, and total yield weight. Data analysis showed that harvesting had a significant effect on all parameters (P-values < 0.001). The average number of fruits dropped from 28 in the first harvest (H1) to 23 in the final. Increased temperatures in July and August most likely caused flower and fruit abortions, which is why this drop occurred. Erickson and Markhart (2001) and Díaz-Pérez (2010) both reported similar findings. Similarly, the average fruit width decreased from 8.49 cm (H1) to 8 cm during the last harvest, presumably due to high temperatures throughout the harvest time. Thuy and Kenji (2015) discovered that high temperatures greatly alter morphological features such as fruit width. Regarding the average length, it declined from 12.13 cm (H1) to 11.46 cm, most likely due to temperature fluctuations in July and August. Saha et al. (2010) found that high temperatures severely restrict fruit growth and length. The overall yield weight also reduced considerably, corresponding with research demonstrating that heat 28.00 8.49 12.13 3.15 23.00 8.00 11.46 2.50 0.00 5.00 10.00 15.00 20.00 25.00 30.00 Number of fruits Average width of fruits (cm) Average length of fruits (cm) Total yield weight (kg) H1 H2 H3 H4 H5 H6 H7 as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 13 Published by IDEAS SPREAD stress causes fruit physiological difficulties and flower and fruit abortion, resulting in losses (Olle, 2009; Angmo et al., 2022). Across all parameters, H1 produced the best results. 3.2 Effect of Variations in Nutrient Recipes on Parameters Taken at Each Harvest In table 3, results showed that F2 produced the best results in terms of number of fruits, average width and average length of fruits, and total yield weight. Table 3. Effect of variations in nutrient recipes on number of fruits, average width and average length of fruits (cm), and total yield weight (kg) The ANOVA findings showed that nutritional recipes had a substantial impact on all examined parameters (P- values < 0.001). F2 produced more fruits (25±10) than F1 (24±9), probably due to F1's lower potassium levels in Phase I (216.60 ppm < 281.00 ppm), which is crucial throughout the blooming and fruiting stages. Potassium has been shown to have a significant impact on plant growth, quality, and yield (Imas and Bansal, 1999; Lester et al., 2006; El-Bassiony et al., 2010), with research showing that bell peppers' parameters are improved by higher potassium fertilization (Fawzy et al., 2005; Sabli and Zamri, 2012). A wider average width (8.31±1.02 cm) was also seen in F2 fruits compared to F1 fruits (8.03±1.00 cm), which may have been caused by F1's lower calcium levels in Phases I and II (57 ppm and 171 ppm < 212 ppm and 190 ppm, respectively). Fruit size and mass are impacted by calcium's effects on cell division and growth (Jing et al., 2024; Norton, 2013; Ali et al., 2021). The average fruit lengths of F2 were longer (11.79±1.19 cm compared to 11.55±0.89 cm), most likely because Phase I had higher potassium levels. Potassium has been shown to have significant effects on the length of fruits and plant development traits (Kusumiyati et al., 2008), and it is essential for crop yield and quality (Pettigrew, 2008), and studies have confirmed its considerable impact on fruit length and plant development characteristics (Kusumiyati et al., 2022; Somapala et al., 2015). Finally, F2 had a larger overall yield weight (2.85±0.89 kg) than F1 (2.68±0.91 kg), which might be attributed to its lower nitrogen levels in Phases I and II (224.00 ppm and 189.00 ppm < 237.50 ppm and 376.18 ppm). According to research, too much nitrogen does not always boost yields or water use efficiency (Ayankojo, 2020), and a balanced nitrogen application is crucial for productivity (FAO, 2002; Aluko, 2015). Overall, F2 had better performance across all parameters. 3.3 Effect of Variations in Bio-Stimulant Dosages on Parameters Taken at Each Harvest: In graph 3, results showed that D3 (150 ml) produced the best results in number of fruits and total yield weight. While D0 (control) outperformed the other options in average width and average length of fruits. Mean ± Standard deviation of: Source of variation: F1 F2 Number of fruits 24±9 25±10 Average width of fruits (cm) 8.03±1.00 8.31±1.02 Average length of fruits (cm) 11.55±0.89 11.79±1.19 Total yield weight (kg) 2.68±0.91 2.85±0.89 as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 14 Published by IDEAS SPREAD Graph 3. Effect of variations in bio-stimulant dosages on number of fruits, average width and average length of fruits (cm), and total yield weight (kg) Data analysis showed that the bio-stimulant doses had significant effects on all tested parameters (P-values < 0.001). In terms of number of fruits, D3 (150 ml) produced the most, its efficiency in enhancing the fruit set, whereas the control group (D0) had the fewest. This is consistent with previous studies demonstrating the involvement of bio-stimulants' in improving blooming, growth, fruit set, and nutrient efficiency (Colla and Rouphael, 2015; Ricci et al., 2019). Ertani et al. (2015) found that bio-stimulants considerably boosted the fruit yield in C. annuum. Conversely, the control group (D0) had the largest average fruit width, with D3 generating the smallest fruits. Higher bio-stimulant doses may produce excessive vegetative growth, limiting the resources available for the fruit development and increasing shading under the canopy (Cmanneri, 2010). According to research, pruning can prevent excessive vegetative growth while also improving fruit size and quality. Similarly, the average fruit length was highest in the control group D0 (12.6 cm) and lowest in D3 (10.91 cm), indicating that vigorous plant development might result in smaller fruits (Kumar et al., 2019). However, PGPR has been shown to increase fruit size, including length and diameter, in many studies (Zapata-Sifuentes et al., 2022; Camacho-Rodríguez et al., 2022). In terms of total yield weight, D3 (150 ml) had the greatest yield (3.90 kg), whereas the control group (D0) had the lowest yield (1.69 kg), most likely owing to the larger number of fruits produced with appropriate bio-stimulant administration. This conclusion aligns with previous studies where a greater fruit count is a primary driver of higher production (Ombódi et al., 2019; Zapata-Sifuentes et al., 2022). Despite the limitations in fruit size parameters, D3 was shown to be the most effective dose for increasing fruit output. 3.4 Effects of Interactions Between Different Nutrient Recipes, Harvests, And Bio-Stimulant Dosages on Parameters Taken at Each Harvest In table 4, the results show that the F2D3 yielded the best results in terms of the number of fruits and total yield weight, while F2D0 produced the greatest results regarding the average width and length of fruits. 13.0 8.8 12.6 1.7 20.0 8.5 12.3 2.7 28.0 7.9 11.1 2.9 37.0 7.7 10.9 3.9 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 Number of fruits Average width of fruits (cm) Average length of fruits (cm) Total yield weight (kg) D0 D1 D2 D3 as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 15 Published by IDEAS SPREAD Table 4. Effect of interactions between nutrient recipes and bio-stimulant dosages on number of fruits, average width and average length of fruits (cm), and total yield weight (kg) The ANOVA table revealed that only the Recipe × Dosage Treatment interaction was significant for all assessed parameters. F2D3 (37.67±4.93) produced the most fruits, while F1D0 (control) had much lower fruit counts. This emphasizes the significance of coupling optimum nutrient formulations with bio-stimulant doses, as fertilizers alone are insufficient to maximize efficiency (Anton-Herrero et al., 2023). These findings are in accordance with a study proving that bio-stimulant treatment increased fruit numbers and overall yield (Golian et al., 2024). Regarding the average fruit width, F2D0 generated the largest average fruit width (8.98±1.78 cm), while F1D2 resulted in smaller fruits (7.69±0.24 cm). This may be linked to plant size and the balance of fruit load and photosynthetic resources (Raharris, 2023). Ding et al. (2017) highlighted the need of maintaining a sustainable crop load for consistent production and quality. However, the control group's greater width contradicts a previous study that PGPR treatment often improves fruit size (Zapata-Sifuentes et al., 2022). For average fruit length, F2D0 yielded the longest fruits (13.20±1.32 cm), while F1D2 produced shorter fruits (10.87±0.28 cm). The decline in fruit size observed with greater bio-stimulant dosages might be attributed to resource competition caused by excessive fruit production (Cmanneri, 2010). A similar experiment on C. annuum found longer fruits in the control group with reduced fruit yield (Chaitra et al., 2024). Finally, for the total yield weight, F2D3 had the largest yield (4.05±0.49 kg), while F1D0 had the lowest (1.52±0.24 kg). This is in accordance with studies confirming the efficacy of PGPR in increasing fruit yield and nutritional value (De Andrade et al., 2023; Ertani et al., 2014; Pereira et al., 2016). Across all parameters, other interactions showed minor but statistically insignificant differences. The interaction between the recipe and the dosage treatment had a significant effect on the fruit production parameters. F2D3 consistently outperformed in most measurements, whereas F2D0 excelled in fruit size. This emphasizes the significance of balancing fertilizer content and bio-stimulant treatments to improve hydroponic bell pepper development. 3.5 Effect of Variations in Nutrient Recipes on Parameters Taken at The End of the Experiment In table 5, results showed that F2 outperformed F1 in both dry root weight and stem length. Table 5. Effect of variations in nutrient recipes on dry root weight (g) and stem length (cm) Mean ± Standard deviation of: Source of variation: F1 F2 Dry root weight (g) 194.33±117.42 205.33±127.33 Stem length (cm) 135.08 ± 9.90 136.79±10.07 The ANOVA results revealed that the different nutrient recipes did not significantly influence the dry root weight and stem length (P-value > 0.05). Despite a lack of statistical significance, F2 performed slightly better than F1, with average dry root weights of 205.33±127.33 g compared to 194.33±117.42 g. Similar experiments on C. annuum L. found no significant influence of the NPK fertilizer on the root dry weight (Ichwan et al., 2023). For stem length, F2 had a small edge in stem length with no statistically significant effect, measuring 136.79±10.07 cm compared to 135.08±9.90 cm in F1. However, the lack of statistical significance might be attributed to Source of variation: Mean ± Standard deviation Number of fruits: Average width of fruits (cm): Average length of fruits (cm): Total yield weight (kg): F1D1 20.33±2.50 8.45±0.34 12.32±0.54 2.68±0.43 F1D2 27.19±3.12 7.69±0.24 10.87±0.28 2.80±0.39 F1D3 34.95±3.75 7.96±0.24 11.17±0.25 3.74±0.64 F1D0 13.24±2.34 8.01±1.90 11.86±1.22 1.52±0.24 F2D1 19.19±2.40 8.59±0.24 12.14±0.41 2.68±0.29 F2D2 28.33±2.94 7.77±0.22 10.91±0.25 2.90±0.32 F2D3 37.67±4.93 7.89±0.19 10.91±0.24 4.05±0.49 F2D0 13.57±2.06 8.98±1.78 13.20±1.32 1.79±0.32 as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 16 Published by IDEAS SPREAD nutritional imbalances or a high plant load, which could hinder stem development (Kaarsemaker, 2018). Furthermore, a study of increasing NPK levels in bell pepper development discovered no significant influence on stem length (Toungos, 2017). F2 had a marginal advantage in both parameters, although the differences were not statistically significant, emphasizing the necessity of balanced nutrient treatments and the possibility of bio- stimulants to improve plant growth. 3.6 Effect of Variations in Bio-Stimulant Dosages on Parameters Taken at The End of the Experiment In graph 4, results showed that D3 outscored the other options in terms of dry root weight and stem length. The data analysis revealed a significant effect of bio-stimulant dosages on both dry root weight and stem length (P-value < 0.001). Among the treatments, D3 (150 ml) generated the highest dry root weight at 386.33 g, whereas D0, the control group, produced the lightest roots, averaging 83.33 g. This result can be related to the effect of Biosciences PHP in transferring helpful bacteria into the root zone (Atomes F.D. Inc., 2023). Such bacteria, particularly plant growth-promoting rhizobacterium (PGPR), have been found to change the root architecture, increasing the total surface area accessible for nutrient and water absorption, resulting in improved plant growth and health (Barnawal et al., 2019). Grover et al. (2021) demonstrated that several PGPR species alter the root architecture by creating phytohormones, volatile organic compounds, and secondary metabolites, which improve the rhizosphere's nutrition exchange capacity. Similarly, D3 (150 ml) produced the longest stems, measuring 148.12 cm compared with 123.03 cm in the control group (D0). PGPR stimulates plant growth and development by secreting regulatory compounds into the rhizosphere (Nehra and Choudhary, 2015). Bai et al. (2007) found that bio-stimulants had a significant impact on plant height and other physical features. Furthermore, Mahmood (2017) found that the beneficial effects of bio-stimulants are proportional to their concentration, with higher concentrations resulting in increased plant height and leaf area. In every parameter, D3 (150 ml) outperformed the other doses, highlighting the importance of bio-stimulants in optimizing plant development by improving root architecture and plant height. 3.7 Effects of Interactions Between Different Nutrient Recipes and Bio-Stimulant Dosages on Parameters Taken at the End of Experiment In table 6, results showed that F2D3 outperformed the other options, having the greatest numbers regarding dry root weight and stem length. 83.00 123.03129.00 131.77 200.00 140.83 386.00 148.12 0.00 50.00 100.00 150.00 200.00 250.00 300.00 350.00 400.00 450.00 Dry root weight (g) Stem length (cm) D0 D1 D2 D3 Graph 4. Effect of variations in bio-stimulant dosages on dry root weight (g) and stem length (cm) as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 17 Published by IDEAS SPREAD Table 6. Effect of interactions between nutrient recipes and bio-stimulant dosages on dry root weight (g) and stem length (cm) Source of variation: Mean ± Standard deviation Dry root weight (g): Stem length (cm): F1D1 128.00±6.93 130.13±0.67 F1D2 192.67±4.16 139.57±0.42 F1D3 374.67±37.17 147.77±1.91 F1D0 82.00±8.72 122.87±1.72 F2D1 130.00±10.39 133.40±1.65 F2D2 208.67±18.58 142.10±2.38 F2D3 398.00±50.24 148.47±1.50 F2D0 84.67±12.06 123.20±2.55 The ANOVA results revealed that the interaction between different nutrient recipes and bio-stimulant dosages had no significant effect on dry root weight and stem length (P-value > 0.05). Despite the lack of statistical significance, there was a notable difference between the highest and lowest averages, with F2D3 generating the greatest dry root weight (398.00±50.24 g) and F1D0 producing the lowest (82.00±8.72 g). A comparative study on Capsicum annuum L. indicated that the combination of PGPR and NPK fertilizers had no significant effect on root dry weight, but varied PGPR concentrations did (Ichwan et al., 2023). Furthermore, it is well acknowledged that the use of adequate mineral fertilizers is critical for improving soil conditions, increasing fertility, and increasing crop yield (Uzakbaevna, 2022). Regarding stem length, F2D3 surpassed F1D0, with averages of 148.47±1.50 cm and 122.87±1.72 cm, respectively. PGPR alters plant physiology, increasing nutrient absorption and root activity efficiency (Khoso et al., 2023). Although the interaction did not reach statistical significance, the combination of bio-stimulants and fertilizers has been proven to improve crop output and overall plant growth (Biernacik et al., 2018). A previous study has shown that the benefits of bio-stimulants vary depending on the combination with various fertilizers. For example, bio-stimulants mixed with phosphorus and potassium increase yields and stimulate overall plant development (Biernacik et al., 2018). Although the interaction effect was not significant, F2D3 consistently outperformed the other treatments in both dry root weight and stem length, suggesting its better efficacy in improving plant growth characteristics. 4. Conclusion This research demonstrates that tailored nutrient solutions and appropriate bio-stimulant dosages can significantly improve the growth and yield of Capsicum annuum in hydroponic systems. Nutrient solution F2, with greater potassium levels, and bio-stimulant dose D3 (150 ml), were the most successful in increasing fruit count, yield, and vegetative growth. Notably, D0 (control) increased fruit size, and the interaction between nutrient recipes and bio-stimulant dosages had a significant effect on important parameters, with F2D3 generating the best total yield. Future studies should explore the long-term effects of these treatments and their economic viability in commercial production settings. Furthermore, using advanced agricultural technology such as precision fertigation systems and climate-controlled greenhouses has the potential to increase hydroponic Capsicum annuum crop productivity and resource efficiency. References Aluko, M. (2015). Nitrogen fertilizer effects on growth, yield and chemical composition of hot pepper (Rodo). International Journal of Agriculture and Crop Sciences, 8, 666–673. https://www.researchgate.net/publication/315799771. Angmo, N. P., Dolma, N. T., Phuntsog, N. N., Chaurasia, N. O., & Stobdan, N. T. (2022). Effect of shading and high temperature amplitude on yield and phenolic contents of greenhouse capsicum (Capsicum annuum L.). Open Access Research Journal of Biology and Pharmacy, 4(1), 30–39. https://doi.org/10.53022/oarjbp.2022.4.1.0053. Antón-Herrero, R., García-Delgado, C., Antón-Herrero, G., Mayans, B., Delgado-Moreno, L., & Eymar, E. (2022). Design of a hydroponic test to evaluate the biostimulant potential of new organic and organomineral products. Scientia Horticulturae, 310, 111753. https://doi.org/10.1016/j.scienta.2022.111753. Atomes FD. Inc. (2023). BIOSCIENCES PHP. Atomes FD. Inc. https://www.atomesbio.com. as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 18 Published by IDEAS SPREAD Ayankojo, I. T., Morgan, K. T., Kadyampakeni, D. M., & Liu, G. D. (2020). Tomato growth, yield, and root development, soil nitrogen and water distribution as affected by nitrogen and irrigation rates on a Florida sandy soil. HortScience, 55(11), 1744–1755. Bai, R. N., Banu, N. R. L., Prakash, J. W., & Goldi, S. J. (2007). Effects of Asparagopsis taxiformis extract on the growth and yield of Phaseolus aureus. Journal of Basic and Applied Biology, 1(1), 6–11. Biernacik, M., Wolski, K., Biernacik, M., Talar-Krasa, M., Leshchenko, O., & Święrszcz, S. (2018). Effect of the application of a biostimulant and mineral fertilization on the mineral element concentration in the sward of forage mixtures cultivated on light soil. Journal of Elementology, 24(1), Article 1569. https://doi.org/10.5601/jelem.2018.23.2.1569. Camacho-Rodríguez, M., Almaraz-Suárez, J. J., Vázquez-Vázquez, C., Angulo-Castro, A., Ríos-Vega, M. E., & González-Mancilla, A. (2022). Effect of plant growth-promoting rhizobacteria on the growth and yield of jalapeño pepper. Revista Mexicana de Ciencias Agrícolas, 13, 185–187. Chaitra, A. J., P, M. G. A., & Manjunath, B. (2024). Effect of bio-stimulants on growth, yield, quality and biotic resistance in chili (Capsicum annuum L.). International Journal of Plant & Soil Science, 36(5), 515–521. https://doi.org/10.9734/ijpss/2024/v36i54548. Cmanneri. (2010, July 9). Balancing growth and fruiting. Weekly Crop Update. https://sites.udel.edu/weeklycropupdate/?p=2233. Colla, G., & Rouphael, Y. (2015). Biostimulants in horticulture. Scientia Horticulturae, 196, 1–2. https://doi.org/10.1016/j.scienta.2015.10.044. De Andrade, L. A., Santos, C. H. B., Frezarin, E. T., Sales, L. R., & Rigobelo, E. C. (2023). Plant growth-promoting rhizobacteria for sustainable agricultural production. Microorganisms, 11(4), 1088. https://doi.org/10.3390/microorganisms11041088. Díaz-Pérez, J. C. (2010). Bell pepper (Capsicum annuum L.) grown on plastic film mulches: Effects on crop microenvironment, physiological attributes, and fruit yield. HortScience, 45, 1196–1204. Ding, N., Chen, Q., Zhu, Z., Peng, L., Ge, S., & Jiang, Y. (2017). Effects of crop load on distribution and utilization of 13C and 15N and fruit quality for dwarf apple trees. Scientific Reports, 7(1), Article 14509. https://doi.org/10.1038/s41598-017-14509-3. El-Bassiony, A. M., Fawzy, Z. F., Abd El-Samad, E. H., Riad, G. S., & National Research Center. (2010). Growth, yield, and fruit quality of sweet pepper plants (Capsicum annuum L.) as affected by potassium fertilization. Journal of American Science, 7(4), 722–729. http://www.americanscience.org. Erickson, A. N., & Markhart, A. H. (2001). Flower production, fruit set, and physiology of bell pepper during elevated temperature and vapor pressure deficit. Journal of the American Society for Horticultural Science, 126, 697–702. Ertani, A., Pizzeghello, D., Francioso, O., Sambo, P., Sanchez-Cortes, S., & Nardi, S. (2014). Capsicum chinensis L. growth and nutraceutical properties are enhanced by biostimulants in a long-term period: Chemical and metabolomics approaches. Frontiers in Plant Science, 5, Article 375. https://doi.org/10.3389/fpls.2014.00375. Ertani, A., Sambo, P., Nicoletto, C., Santagata, S., Schiavon, M., & Nardi, S. (2015). The use of organic biostimulants in hot pepper plants to help low input sustainable agriculture. Chemical and Biological Technologies in Agriculture, 2(1), Article 39. https://doi.org/10.1186/s40538-015-0039-z. FAO. (2002). Optimizing nitrogen use on the farm. Food and Agriculture Organization of the United Nations. https://www.fao.org/4/y5146e/y5146e09.htm. FAOSTAT. (2023). Production/yield of chilies and peppers, green worldwide and in Lebanon for the years 2020 and 2021. Food and Agriculture Organization of the United Nations. Fawzy, Z. F., Behairy, A. G., & Shehata, S. A. (2005). Effect of potassium fertilizer on growth and yield of sweet pepper plants (Capsicum annuum L.). Egyptian Journal of Agricultural Research, 2, 559–610. Golian, M., Mezeyová, I., Andrejiová, A., Hegedűsová, A., Adamec, S., Štefániková, J., & Árvay, J. (2024). Effects of selected biostimulants on qualitative and quantitative parameters of nine cultivars of the genus Capsicum spp. Open Agriculture, 9(1). https://doi.org/10.1515/opag-2022-0266. Grover, M., Bodhankar, S., Sharma, A., Sharma, P., Singh, J., & Nain, L. (2021). PGPR mediated alterations in root traits: Way toward sustainable crop production. Frontiers in Sustainable Food Systems, 4. as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 19 Published by IDEAS SPREAD https://doi.org/10.3389/fsufs.2020.618230. Ichwan, B., Eliyanti, E., & Irianto, I. (2023). Increasing the growth and yield of red chili with PGPR and NPK fertilizer in ultisol dry land. Russian Journal of Agricultural and Socio-Economic Sciences, 8(2), 56–63. Imas, P., & Bansal, S. K. (1999). Potassium and integrated nutrient management in potato. In Proceedings of the Global Conference on Potato (pp. 85–90). New Delhi, India. Kaarsemaker, R. (2018, January 29). Nutrient deficiency in peppers despite perfect drainage values. Greenhouses Magazine. https://www.ingreenhouses.com/nutrient-deficiency-peppers-despite-perfect-drainage-values/. Kelley, W. T., Boyhan, G. E., Harrison, K. A., Granberry, D. M., Langston, D. B., Sparks, A. N., Culpepper, S., Hurst, W. C., & Fonsah, E. G. (2009). Commercial pepper production handbook (University of Georgia Research Bulletin 1309). Khoso, M. A., Wagan, S., Alam, I., Hussain, A., Ali, Q., Saha, S., Poudel, T. R., Manghwar, H., & Liu, F. (2023). Impact of plant growth-promoting rhizobacteria (PGPR) on plant nutrition and root characteristics: Current perspective. Plant Stress, 11, Article 100341. https://doi.org/10.1016/j.stress.2023.100341. Kumar, K., Singh, D. P., Saini, P. K., Yadav, R. K., Chandrashekhar Azad University of Agriculture and Technology, & Narendra Deva University of Agriculture and Technology. (2019). Progress in pruning to vegetable crops: A review. International Journal of Advances in Agricultural Science and Technology, 6(2), 19–32. Kusumiyati, K., Syifa, R. J., & Farida, F. (2022). Effect of various varieties and dosage of potassium fertilizer on growth, yield, and quality of red chili (Capsicum annuum L.). Open Agriculture, 7(1), 948–961. https://doi.org/10.1515/opag-2022-0151. Lester, G. E., Jifon, J. L., & Makus, D. J. (2006). Supplemental foliar potassium applications with or without a surfactant can enhance netted muskmelon quality. HortScience, 41(3), 741–744. Mahmood, N. (2017). Effect of biostimulants on growth, yield and quality of bell pepper cv. Yolo Wonder. The Pakistan Journal of Agricultural Sciences, 54(2), 311–317. https://doi.org/10.21162/pakjas/17.5653. Olle, M., & Bender, I. (2009). Causes and control of calcium deficiency disorders in vegetables: A review. The Journal of Horticultural Science and Biotechnology, 84, 577–584. Ombódi, A., Csorbainé Gógán, A., Birkás, Z., Kappel, N., Morikawa, C. K., Koczka, N., et al. (2019). Effects of mycorrhiza inoculation and grafting for sweet pepper (Capsicum annuum L.) crop under low-tech greenhouse conditions. Not. Bot. Horti. Agrobo., 47, 1238–1245. https://doi.org/10.15835/nbha47411641. Pereira, J. A. P., Vieira, I. J. C., Freitas, M. S. M., Prins, C. L., Martins, M. A., & Rodrigues, R. (2016). Effects of arbuscular mycorrhizal fungi on Capsicum spp. Journal of Agricultural Science, 154, 828–849. https://doi.org/10.1017/S0021859615000714. Pettigrew, W. T. (2008). Potassium influences on yield and quality production for maize, wheat, soybean and cotton. Physiologia Plantarum, 133(4), 670–681. https://doi.org/10.1111/j.1399-3054.2008.01073.x. Raharris. (2023, August 25). Factors affecting bell pepper fruit size and shape. Weekly Crop Update. https://sites.udel.edu/weeklycropupdate/?p=23337. Ricci, M., Tilbury, L., Daridon, B., & Sukalac, K. (2019). General principles to justify plant biostimulant claims. Frontiers in Plant Science, 10, Article 494. https://doi.org/10.3389/fpls.2019.00494. Rouphael, Y., & Colla, G. (2020). Biostimulants in agriculture. Frontiers in Plant Science, 11, 40. Sabli, H., & Zamri, H. M. (2012). Fertigation of bell pepper (Capsicum annuum L.) in a soil-less greenhouse system: Effects of fertilizer formulation and irrigation frequency. https://theses.ncl.ac.uk/jspui/bitstream/10443/1543/1/Haji%20Sabli%2012.pdf. Saha, S., Hossain, M., Rahman, M., Kuo, C., & Abdullah, S. (2010). Effect of high temperature stress on the performance of twelve sweet pepper genotypes. Bangladesh Journal of Agricultural Research, 35(3), 525– 534. https://doi.org/10.3329/bjar.v35i3.6459. Sardare, M. M. D., & Admane, M. S. V. (2013). A review on plant without soil – hydroponics. International Journal of Research in Engineering and Technology, 2(3), 299–305. Somapala, K., Weerahewa, H., & Thrikawala, S. (2015). Effect of potassium on growth, fruit quality improvements, and resistance to anthracnose in field grown capsicum (Capsicum annuum L. cv. 'Hungarian yellow wax'). International Journal of Multidisciplinary Studies, 2(2), 63. https://doi.org/10.4038/ijms.v2i2.75. as.ideasspread.org Agricultural Science Vol. 7, No. 1; 2025 20 Published by IDEAS SPREAD Swamy, K. R. M. (2023). Origin, distribution, taxonomy, botanical description, genetic diversity and breeding of capsicum (Capsicum annuum L.). International Journal of Development Research, 13(3), 61956–61977. Tabet, E., Sleiman, P., Hosri, C., Rouphael, S., & Farah, L. (2020). Agricultural Science. IDEAS SPREAD, 2(1), 243–256. https://doi.org/10.30560/as.v2n1p243. Thuy, N. T. L., & Kenji, N. M. (2015). Effect of high temperature on fruit productivity and seed-set of sweet pepper (Capsicum annuum L.) in the field condition. Journal of Agricultural Science and Technology A, 5(12), 175– 179. https://doi.org/10.17265/2161-6256/2015.12.010. Toungos, M. D. (2017). The effects of different levels of inorganic fertilizer (NPK 15:15:15) on growth and yield of sweet pepper (Capsicum annuum) in Mubi, Nigeria. International Journal of Development Research, 7(9), 14733–14738. http://www.journalijdr.com. Uzakbaevna, I. A. (2022). The effect of unconventional fertilizers on the growth and development of cotton. International Journal of Integrated Education, 5, 226–229. Zapata-Sifuentes, G., Hernandez-Montiel, L. G., Saenz-Mata, J., Fortis-Hernandez, M., Blanco-Contreras, E., Chiquito-Contreras, R. G., & Preciado-Rangel, P. (2022). Plant growth-promoting rhizobacteria improve growth and fruit quality of cucumber under greenhouse conditions. Plants, 11(12), 1612. https://doi.org/10.3390/plants11121612. Copyrights Copyright for this article is retained by the author(s), with first publication rights granted to the journal. This is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/). << /ASCII85EncodePages false /AllowTransparency false /AutoPositionEPSFiles true /AutoRotatePages /None /Binding /Left /CalGrayProfile (Dot Gain 20%) /CalRGBProfile (sRGB IEC61966-2.1) /CalCMYKProfile (U.S. Web Coated \050SWOP\051 v2) /sRGBProfile (sRGB IEC61966-2.1) /CannotEmbedFontPolicy /Error /CompatibilityLevel 1.4 /CompressObjects /Tags /CompressPages true /ConvertImagesToIndexed true /PassThroughJPEGImages true /CreateJobTicket false /DefaultRenderingIntent /Default /DetectBlends true /DetectCurves 0.0000 /ColorConversionStrategy /CMYK /DoThumbnails false /EmbedAllFonts true /EmbedOpenType false /ParseICCProfilesInComments true /EmbedJobOptions true /DSCReportingLevel 0 /EmitDSCWarnings false /EndPage -1 /ImageMemory 1048576 /LockDistillerParams false /MaxSubsetPct 100 /Optimize true /OPM 1 /ParseDSCComments true /ParseDSCCommentsForDocInfo true /PreserveCopyPage true /PreserveDICMYKValues true /PreserveEPSInfo true /PreserveFlatness true /PreserveHalftoneInfo false /PreserveOPIComments true /PreserveOverprintSettings true /StartPage 1 /SubsetFonts true /TransferFunctionInfo /Apply /UCRandBGInfo /Preserve /UsePrologue false /ColorSettingsFile () /AlwaysEmbed [ true ] /NeverEmbed [ true ] /AntiAliasColorImages false /CropColorImages true /ColorImageMinResolution 300 /ColorImageMinResolutionPolicy /OK /DownsampleColorImages true /ColorImageDownsampleType /Bicubic /ColorImageResolution 300 /ColorImageDepth -1 /ColorImageMinDownsampleDepth 1 /ColorImageDownsampleThreshold 1.50000 /EncodeColorImages true /ColorImageFilter /DCTEncode /AutoFilterColorImages true /ColorImageAutoFilterStrategy /JPEG /ColorACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /ColorImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000ColorACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000ColorImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasGrayImages false /CropGrayImages true /GrayImageMinResolution 300 /GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 300 /GrayImageDepth -1 /GrayImageMinDownsampleDepth 2 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /GrayImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000GrayACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000GrayImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasMonoImages false /CropMonoImages true /MonoImageMinResolution 1200 /MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 1200 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict << /K -1 >> /AllowPSXObjects false /CheckCompliance [ /None ] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile () /PDFXOutputConditionIdentifier () /PDFXOutputCondition () /PDFXRegistryName () /PDFXTrapped /False /CreateJDFFile false /Description << /ARA /BGR /CHS /CHT /CZE /DAN /DEU /ESP /ETI /FRA /GRE /HEB /HRV (Za stvaranje Adobe PDF dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. Stvoreni PDF dokumenti mogu se otvoriti Acrobat i Adobe Reader 5.0 i kasnijim verzijama.) /HUN /ITA /JPN /KOR /LTH /LVI /NLD (Gebruik deze instellingen om Adobe PDF-documenten te maken die zijn geoptimaliseerd voor prepress-afdrukken van hoge kwaliteit. De gemaakte PDF-documenten kunnen worden geopend met Acrobat en Adobe Reader 5.0 en hoger.) /NOR /POL /PTB /RUM /RUS /SKY /SLV /SUO /SVE /TUR /UKR /ENU (Use these settings to create Adobe PDF documents best suited for high-quality prepress printing. Created PDF documents can be opened with Acrobat and Adobe Reader 5.0 and later.) >> /Namespace [ (Adobe) (Common) (1.0) ] /OtherNamespaces [ << /AsReaderSpreads false /CropImagesToFrames true /ErrorControl /WarnAndContinue /FlattenerIgnoreSpreadOverrides false /IncludeGuidesGrids false /IncludeNonPrinting false /IncludeSlug false /Namespace [ (Adobe) (InDesign) (4.0) ] /OmitPlacedBitmaps false /OmitPlacedEPS false /OmitPlacedPDF false /SimulateOverprint /Legacy >> << /AddBleedMarks false /AddColorBars false /AddCropMarks false /AddPageInfo false /AddRegMarks false /ConvertColors /ConvertToCMYK /DestinationProfileName () /DestinationProfileSelector /DocumentCMYK /Downsample16BitImages true /FlattenerPreset << /PresetSelector /MediumResolution >> /FormElements false /GenerateStructure false /IncludeBookmarks false /IncludeHyperlinks false /IncludeInteractive false /IncludeLayers false /IncludeProfiles false /MultimediaHandling /UseObjectSettings /Namespace [ (Adobe) (CreativeSuite) (2.0) ] /PDFXOutputIntentProfileSelector /DocumentCMYK /PreserveEditing true /UntaggedCMYKHandling /LeaveUntagged /UntaggedRGBHandling /UseDocumentProfile /UseDocumentBleed false >> ] >> setdistillerparams << /HWResolution [2400 2400] /PageSize [612.000 792.000] >> setpagedevice