Research Article
Sustainable Fertilization with Palm Residues, Organic Sulfur and Garlic Extract and its Effect on the Growth, Yield, and Chemical Characteristics of Bunching Onion
Elaf Hamza Wali1* and Yasamen Fadhil Salloom2
1Department of Horticulture and Landscape Engineering, College of Agricultural Engineering Sciences, University of Baghdad, Iraq.
Abstract | This study was conducted to investigate the impact of fertilization with palm residues (0, 20, and 30 tons ha-¹), organic sulfur (0, 300, and 600 kg ha-¹), and foliar spraying with garlic extract (0 and 6 mL L-¹) on selected vegetative traits, yield, and the chemical composition of bunching onion bulbs. The experiment was conducted in a RCBD design using a split-plot layout with three replications, comprising 18 experimental units per replicate, each containing 150 plants. The results revealed that the application of palm residues at 30 tons ha-¹, organic sulfur at 600 kg ha-¹, and foliar spraying with garlic extract at 6 mL L-¹, when applied individually, significantly enhanced nitrogen, phosphorus percentages, and sulfur in the bulbs, leaf chlorophyll content, the height of plant , plant leaf area, in addition to total yield. Regarding the three-way interaction among the studied factors, the combined treatment of palm residues at 30 tons ha-¹ + organic sulfur at 600 kg ha-¹ + garlic extract at 6 mL L-¹ produced the most pronounced improvements, achieving significant increases in nitrogen (3.68%) and phosphorus (0.400%) content in the bulbs, chlorophyll concentration in the leaves (131.4 mg 100 g-¹ fresh weight), leaf area (15.31 dm²), and total yield (89.33 tons ha-¹).
Received | July 23, 2025; Accepted | October 01, 2025; Published | June 30, 2026
*Correspondence | Elaf Hamza Wali, Department of Horticulture and Landscape Engineering – College of Agricultural Engineering Sciences – University of Baghdad; Email: [email protected]
Citation | Wali, E.H and Y.F. Salloom. 2026. Sustainable fertilization with palm residues, organic sulfur, and garlic extract and its effect on the growth, yield, and chemical characteristics of bunching onion. Pakistan Journal of Agricultural Research, 39(2): 83-94.
DOI | https://dx.doi.org/10.17582/journal.pjar/2026/39.2.83.94
Keywords | Green onion, Palm residues, Organic sulfur, Garlic extract, Sustainable fertilization
Copyright: 2026 by the authors. Licensee ResearchersLinks Ltd, England, UK.
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Introduction
The global agricultural sector is witnessing a growing trend towards adopting sustainable agricultural practices that aim to achieve a balance between increasing agricultural production and ensuring food safety on the one hand and preserving environmental resources and reducing pollution on the other. In this context, the use of agricultural residues and organic materials is considered an effective alternative to chemical fertilizers, because of its role in improving soil fertility and raising the efficiency of nutrient absorption, in addition to promoting the accumulation of bioactive compounds in plants (Ali et al., 2025). One of the priority vegetable crops is green onions (Allium fistulosum L.) a member of Alliaceae family (Mahmood et al., 2021), being a leading crop in Iraq and other countries worldwide. This crop is known for its high carbohydrates and mineral contents, specifically sulfur (Liu et al., 2024), which is involved in the synthesis of volatile sulfur compounds responsible for the pungent taste and unique aroma of the crop. Clinically, in addition to its food nourishment, the green onion has significant therapeutic effect because of the majority active compound constituents including quercetin (Kim et al., 2023). Quercetin is a natural antioxidant that exists in high quantity in green onion and serves as a principal contributor to counter the deleterious action of free radicals, which underlie many chronic diseases such as cardiovascular diseases and some cancers. It’s known to also increase immune system responses (Javed, 2025; Kim et al., 2023). Green onion also has other biologically active substances, such as kaempferol and phenolics (Zhao et al., 2021) and important vitamins such as C, A, B9 (Akbar et al., 2024; Amare, 2020).These reinforce the nutritional and medicinal properties of bunching onion.
While heavy use of chemical fertilizers in recent farming systems has resulted in increasing the agricultural productivity, it has also caused several negative impacts for both environment and human health such as groundwater pollution and deterioration of soil fertility. As environmental problems have become more serious and global attention focuses on how to accomplish sustainable food security, it is urgent that safe and natural alternatives which decrease dependence on chemical inputs should be developed (Abdel-Hakim, 2020). In this regard, organic fertilizers are a sustainable and effective choice for enhancing the physical and chemical characteristics of soil and increasing its content of organic matter and available nutrients (Asha et al., 2023; Fayhaa et al., 2025; Mohammed et al., 2025). Moreover, organic fertilizers support the activity of beneficial soil microorganisms and strengthen ecological balance within agroecosystems, making organic farming a strategic approach to producing safe, healthy food while preserving the environment and biodiversity (Al-Hlfie & Hussein, 2024; Du et al., 2022).
Among promising organic fertilizers, palm residues stand out as a natural resource capable of improving soil characteristics (Aram & Khattab, 2018; Ghouili et al., 2023), increasing nutrient availability and uptake by plants, and consequently enhancing plant nutrition and productivity (Le Guyader et al., 2024; Muslat & Salih, 2017). Previous studies have shown that when 32 tons per hectare of palm fronds were added resulted in significant improvements in most vegetative, qualitative, and yield traits of potato compared with other application levels (Shaker & Abdul Rasool, 2023). Likewise, organic sulfur is considered an essential element to support the plants’ growth and development (Desouza et al., 2015; He et al., 2010), particularly in crops such as green onion, where both productivity and quality are highly influenced by sulfur availability (Ogunbode & Tijani, 2020; Taru et al., 2025). The importance of sulfur lies in its biological association with nitrogen in the synthesis of amino acids and proteins (Demissie & Shiferaw, 2024). Its deficiency leads to imbalances in plant protein content (Khorsheed & Al-Tamimi, 2018; Sable et al., 2024). Research has further demonstrated that applying agricultural sulfur in combination with poultry residues significantly improved all vegetative and productivity traits of red onion (Al-Amri & Al-Abdaly, 2021; Manik et al., 2024; Tilahun et al., 2021).
In the search for eco-friendly alternatives, recent studies have increasingly focused on the use of plant extracts as effective biostimulants. These extracts contribute to the principles of sustainable agricultural development by utilizing renewable natural resources and minimize the environmental effect of chemical inputs (Lorin & Al-Juboori, 2022). Among these, garlic extract has gained considerable attention due to its richness in bioactive compounds such as allicin, sulfur-containing compounds, phenolics, and flavonoids (Sunanta et al., 2023). These compounds exhibit growth-promoting properties, enhance nutrient uptake, and provide resistance against plant diseases (Al-Mousawi et al., 2024; Bar et al., 2022; Bulgari et al., 2019). A recent study on cucumber (Maitig et al., 2025) revealed that foliar application containing garlic extract with a concentration of 3.75 mL L-¹ significantly improved most measured traits, while the concentration of 5 mL L-¹ resulted in the highest set of fruit percentage. Researchers emphasized the critical role of plant extracts, particularly garlic extract, in enhancing plant growth and productivity.
Despite the progress made in this field, studies examining the combined effects of palm residues, organic sulfur, and garlic extract on green onion remain limited. Therefore, the present study was designed to evaluate the function of these natural sources in enhancing productivity of green onion and boosting its content of bioactive medicinal compounds, thereby supporting sustainable agriculture and the production of safe and healthy food.
Material and Methods
The field trial was conducted at Research Station (A), which is associated with the College of Agricultural Engineering Sciences, University of Baghdad, in the spring growing season from 1 October 2024, to 15 March 2025. The aim was to evaluate the effects of fertilization with palm residues, organic sulfur, and foliar spraying with garlic extract on vegetative traits, total yield, nutrient content, and chlorophyll concentration in bunching onion.
The field was divided into three replications, each comprising 18 experimental units. Each experimental unit was represented by a raised bed measuring 1 × 1 m². Plants were grown in rows spaced 10 cm apart, with 7 cm spacing between plants within the row, yielding a combined total of 150 plants per experimental unit. A 0.50 m buffer was left between units to prevent treatment overlap. Well-decomposed palm residue compost was applied according to the designated treatments, followed by the installation of a drip irrigation system. Seeds of the green onion hybrid Bunching Onion were sown in Styrofoam trays at a private nursery on 1 October 2024 and transplanted into the permanent field on 15 November once the saplings had developed 2–3 true leaves.
The experiment included three factors:
The garlic extract was prepared by blending 150 g of garlic cloves with 150 mL of distilled water using a blender. The mixture passed through two layers of muslin cloth to get a 100% extract, from which the required concentration of 6 mL L-¹ was prepared (Al-Hajj et al., 2022).
The experimental setup as a split-plot arrangement within a RCBD. Palm residue fertilization treatments were assigned to the main plots, while organic sulfur and garlic extract treatments were randomly distributed within the subplots. Treatment averages were compared utilizing the least significant difference test (LSD) at the 0.05 probability level (Elsahooki,. and Waheeb. 1990).
Measured traits
The following vegetative, yield, and nutrient traits were assessed:
Results
Nitrogen percentage
The results presented in Table 1 revealed a statistically significant differences were observed in the nitrogen percentage in green onion bulbs due to varying levels of date palm waste fertilizer. The highest value (3.29%) was recorded under treatment T2. Fertilization with organic sulfur also exerted a significant effect on nitrogen content in the bulbs, particularly under treatment S2, which achieved 3.16%. Regarding garlic extract foliar spraying, treatment G1 outperformed others with a nitrogen content of 2.90%.
Concerning the two-way interaction between palm waste and organic sulfur (T × S), the T2S2 combination demonstrated a clear superiority, yielding the highest nitrogen content in bulbs at 3.59%, compared to the lowest value (2.26%) recorded under T1S0.
In the case of the T × G interaction (palm waste × garlic extract), a significant increase was observed in this trait, reaching its peak value of 3.36% under the T2G1 treatment, while the lowest value (2.43%) was recorded under T0G0. For the S × G interaction (organic sulfur × garlic extract), treatment S2G0 gave the highest nitrogen content in bulbs at 3.20%.
Regarding the three-way interaction among all study factors (T × S × G), statistical analysis revealed that the T2S2G1 treatment significantly outperformed all others, elevating nitrogen content in green onion bulbs to 3.68%. In contrast, the lowest nitrogen content (1.75%) was recorded under the T0S0G0 treatment.
Table 1: Effect of fertilization with palm residues, organic sulfur, and garlic extract spray on the nitrogen percentage in green onion bulbs (%)
|
palm residues(T) |
organic sulfurb (S) |
Garlic extract (G) |
T × S |
|
|
G0 |
G1 |
|||
|
T0 |
S0 |
1.75 |
2.83 |
٢.٢٩ |
|
S1 |
2.78 |
2.80 |
٢.٧٩ |
|
|
S2 |
2.78 |
3.08 |
٢.٩٣ |
|
|
T1 |
S0 |
2.30 |
2.21 |
٢.٢٦ |
|
S1 |
2.14 |
2.48 |
٢.٣١ |
|
|
S2 |
3.33 |
2.63 |
٢.٩٨ |
|
|
T2 |
S0 |
3.27 |
2.86 |
٣.٠٦ |
|
S1 |
2.88 |
3.53 |
٣.٢٠ |
|
|
S2 |
3.50 |
3.68 |
٣.٥٩ |
|
|
L.S.D. 0.05 |
0.1605 |
0.1135 |
||
|
T × G |
T |
|||
|
T0 |
2.43 |
2.90 |
٢.٦٧ |
|
|
T1 |
2.59 |
2.44 |
٢.٥١ |
|
|
T2 |
3.22 |
3.36 |
٣.٢٩ |
|
|
L.S.D. 0.05 |
0.0927 |
0.1387 |
||
|
S × G |
||||
|
S0 |
2.44 |
2.63 |
٢.٥٤ |
|
|
S1 |
2.60 |
2.93 |
٢.٧٧ |
|
|
S2 |
3.20 |
3.13 |
٣.١٦ |
|
|
L.S.D. 0.05 |
0.0927 |
0.0655 |
||
|
G |
2.75 |
٢.٩٠ |
||
|
L.S.D. 0.05 |
0.0535 |
|||
Phosphorus percentage
The results revealed that the application of date palm waste fertilizer led to an increase in phosphorus percentage in green onion bulbs (Table 2), particularly under treatment T2, which recorded 0.354%. Regarding the effect of organic sulfur fertilization, treatment S2 stood out as the most effective, achieving a phosphorus content of 0.358%. As for garlic extract application, treatment G1 showed superiority, with a phosphorus content of 0.350%.
Table 2: Effect of fertilization with palm residues, organic sulfur, and garlic extract spray on the phosphorus percentage in green onion bulbs (%)
|
palm residues (T) |
organic sulfur (S) |
Garlic extract (G) |
T × S |
|
|
G0 |
G1 |
|||
|
T0 |
S0 |
0.310 |
0.327 |
٠.٣١٨ |
|
S1 |
0.357 |
0.310 |
٠.٣٣٣ |
|
|
S2 |
0.370 |
0.360 |
٠.٣٦٥ |
|
|
T1 |
S0 |
0.330 |
0.367 |
٠.٣٤٨ |
|
S1 |
0.320 |
0.360 |
٠.٣٤٠ |
|
|
S2 |
0.380 |
0.330 |
٠.٣٥٥ |
|
|
T2 |
S0 |
0.340 |
0.317 |
٠.٣٢٨ |
|
S1 |
0.380 |
0.377 |
٠.٣٧٨ |
|
|
S2 |
0.310 |
0.400 |
٠.٣٥٥ |
|
|
L.S.D. 0.05 |
0.0106 |
0.0075 |
||
|
T × G |
T |
|||
|
T0 |
0.346 |
0.332 |
٠.٣٣٩ |
|
|
T1 |
0.343 |
0.352 |
٠.٣٤٨ |
|
|
T2 |
0.343 |
0.364 |
٠.٣٥٤ |
|
|
L.S.D. 0.05 |
0.0061 |
0.0076 |
||
|
S × G |
||||
|
S0 |
0.327 |
0.337 |
٠.٣٣٢ |
|
|
S1 |
0.352 |
0.349 |
٠.٣٥١ |
|
|
S2 |
0.353 |
0.363 |
٠.٣٥٨ |
|
|
L.S.D. 0.05 |
0.0061 |
0.0043 |
||
|
G |
0.344 |
٠.٣٥٠ |
||
|
L.S.D. 0.05 |
0.0035 |
|||
In term of the two-way interaction between palm waste and organic sulfur (T × S), treatment T2S1 demonstrated a statistically significant effect, recording the highest phosphorus value in bulbs at 0.378%, compared to the lowest value (0.318%) observed under T0S0. The interaction between palm waste and garlic extract (T × G) also showed significant superiority under treatment T2G1, where phosphorus content reached 0.364%, whilst the minimum value was (0.332%) was for T0G1. The interaction between organic sulfur and garlic extract (S × G) significantly enhanced phosphorus concentration, with treatment S2G1 achieving the highest content at 0.363%, compared to S0G0, which achieved the minimum value of (0.327%).
In term of three-way interaction (T × S × G) revealed that treatment T2S2G1 was significantly superior in increasing phosphorus percentage, reaching 0.400%. In contrast, the lowest phosphorus concentrations were observed under the triple interaction treatments T0S0G0, T0S1G1, and T2S2G0, all of which recorded the same minimal value of 0.310%.
Sulfur content in green onion bulbs (mg 100g-¹)
Table 3 reveals clear effects of the individual factors (palm waste, organic sulfur, garlic extract) on the sulfur content in green onion bulbs. For palm waste fertilization treatments, the results showed that treatment T1 (20 tons ha-¹) achieved the highest average of 779.6 mg 100g-¹ compared to treatment T2 (30 tons ha-¹), which recorded 749.6 mg 100g-¹, and the control treatment T0 (0 tons ha-¹), which was the lowest with an average of 707.2 mg 100g-¹. The effect of organic sulfur was the most prominent among the individual factors. Treatment S2 (600 kg ha-¹) recorded the highest sulfur content value of 900.2 mg 100g-¹, while the lowest values were in the control treatment (S0), with an average of 619.0 mg 100g-¹. Regarding foliar spraying with garlic extract, its use increased the average sulfur content to 770.1 mg 100g-¹, compared to no spraying (G0), which recorded 720.8 mg 100g-¹. This indicates its positive effect on improving sulfur content.
Concerning the three-way interactions between the factors (palm waste × organic sulfur × garlic extract), the highest value was recorded for the interaction between the second level of palm waste (T1, 20 tons ha-¹), the third level of organic sulfur (S2, 600 kg ha-¹), and spraying with garlic extract (G1, 6 ml L-¹), where the sulfur content reached 953.4 mg 100g-¹. In contrast, the lowest value was recorded for the interaction treatment T2S0G0 (30 tons ha-¹ + 0 kg ha-¹ + 0 ml L-¹) at 516.4 mg 100g-¹.
These results demonstrate that the effect of each individual factor is clearly reflected in the sulfur content, but the highest values were achieved by combining the appropriate levels of these factors together.
Table 3: Effect of fertilization with palm residues, organic sulfur, and garlic extract spray on the sulfur content of green onion bulbs (mg 100 g-¹)
|
palm residues(T) |
organic sulfur(S) |
Garlic extract (G) |
T × S |
|
|
G0 |
G1 |
|||
|
T0 |
S0 |
568.6 |
582.9 |
575.8 |
|
S1 |
628.6 |
٦٤٦.١ |
637.3 |
|
|
S2 |
905.5 |
٩١١.٧ |
908.6 |
|
|
T1 |
S0 |
647.9 |
٧٠٨.٨ |
678.4 |
|
S1 |
736.6 |
٧٤٩.٣ |
743.0 |
|
|
S2 |
881.6 |
٩٥٣.٤ |
917.5 |
|
|
T2 |
S0 |
516.4 |
٦٨٩.٥ |
602.9 |
|
S1 |
746.7 |
٧٩٥.٨ |
771.3 |
|
|
S2 |
885.4 |
٨٩٣.٧ |
874.5 |
|
|
L.S.D. 0.05 |
24.30 |
19.35 |
||
|
T × G |
T |
|||
|
T0 |
700.9 |
713.6 |
707.2 |
|
|
T1 |
755.4 |
803.8 |
779.6 |
|
|
T2 |
706.2 |
793.0 |
749.6 |
|
|
L.S.D. 0.05 |
17.89 |
17.90 |
||
|
S × G |
||||
|
S0 |
577.6 |
660.4 |
619.0 |
|
|
S1 |
704.0 |
730.4 |
717.2 |
|
|
S2 |
880.8 |
919.6 |
900.2 |
|
|
L.S.D. 0.05 |
12.79 |
9.05 |
||
|
G |
720.8 |
770.1 |
||
|
L.S.D. 0.05 |
7.39 |
|||
Leaf chlorophyll content (mg 100g-¹ fresh weight)
Results from Table 4 show that variation in palm waste fertilizer application levels had a clear effect on increasing chlorophyll concentration in green onion leaves. Treatment T2 recorded the highest value at 97.9 mg per 100 g fresh weight, significantly outperforming the control treatment T0, where chlorophyll concentration dropped to 69.4 mg per 100 g fresh weight. The application of organic sulfur also stimulated this trait: treatment S2 achieved the highest chlorophyll content at 110.0 mg per 100 g fresh weight, compared to S0, which recorded the lowest value at 63.5 mg per 100 g fresh weight. Regarding garlic extract foliar spraying, treatment G1 significantly surpassed G0, with chlorophyll concentration reaching 91.9 mg per 100 g fresh weight under G1.
Concerning the two-way interaction between date palm waste and organic sulfur (T × S), treatment T2S2 showed clear superiority, yielding the highest chlorophyll content at 124.7 mg 100 g fresh weight. This was significantly higher than the lowest value of 49.8 mg 100 g fresh weight recorded in treatment T0S0. Similarly, the two-way interaction between palm waste and garlic extract (T × G) revealed that treatment T2G1 was superior, achieving 105.1 mg per 100 g fresh weight. The interaction between organic sulfur and garlic extract (S × G) also had a statistically significant effect, with treatment S2G1 recording the highest chlorophyll concentration at 115.4 mg per 100 g fresh weight.
Most notably, the three-way interaction among all three factors (T × S × G) produced the most pronounced effect: treatment T2S2G1 achieved the absolute highest chlorophyll content at 131.4 mg 100 g fresh weight, which was the lowest value a mere 42.4 mg per 100 g fresh weight was recorded under treatment T0S0G0.
Table 4: Effect of fertilization with palm residues, organic sulfur, and garlic extract spray on leaf chlorophyll content (mg 100 g-¹ fresh weight)
|
palm residues(T) |
organic sulfur(S) |
Garlic extract (G) |
T × S |
|
|
G0 |
G1 |
|||
|
T0 |
S0 |
42.4 |
57.2 |
٤٩.٨ |
|
S1 |
69.0 |
73.3 |
٧١.١ |
|
|
S2 |
82.9 |
91.3 |
٨٧.١ |
|
|
T1 |
S0 |
62.6 |
71.6 |
٦٧.١ |
|
S1 |
79.1 |
94.9 |
٨٧.٠ |
|
|
S2 |
113.0 |
123.5 |
١١٨.٢ |
|
|
T2 |
S0 |
65.8 |
81.1 |
٧٣.٥ |
|
S1 |
88.5 |
102.7 |
٩٥.٦ |
|
|
S2 |
118.0 |
131.4 |
١٢٤.٧ |
|
|
L.S.D. 0.05 |
21.44 |
17.39 |
||
|
T × G |
T |
|||
|
T0 |
64.8 |
73.9 |
٦٩.٤ |
|
|
T1 |
84.9 |
96.9 |
٩٠.٨ |
|
|
T2 |
90.8 |
105.1 |
٩٧.٩ |
|
|
L.S.D. 0.05 |
16.27 |
16.39 |
||
|
S × G |
||||
|
S0 |
57.0 |
70.0 |
٦٣.٥ |
|
|
S1 |
78.9 |
90.3 |
٨٤.٦ |
|
|
S2 |
104.6 |
115.4 |
١١٠.٠ |
|
|
L.S.D. 0.05 |
11.05 |
7.81 |
||
|
G |
80.2 |
٩١.٩ |
||
|
L.S.D. 0.05 |
6.38 |
|||
Plant height (cm)
Results from Table 5 indicate that varying levels of palm waste fertilizer application significantly increased the height of green onion plants. Treatment T2 (30 tons ha-¹) recorded the highest average height of 55.21 cm, outperforming treatment T0 (0 tons ha-¹), which recorded the lowest height of 50.97 cm. The use of organic sulfur also contributed to improving this trait, with treatment S2 (600 kg ha-¹) achieving a height of 54.95 cm compared to treatment S0 (0 kg ha-¹), which recorded 50.41 cm. Regarding the effect of foliar spraying with garlic extract, treatment G1 (6 ml L-¹) showed clear superiority with a plant height of 53.51 cm.
Table 5: Effect of fertilization with palm residues, organic sulfur, and garlic extract spray on plant height (cm)
|
palm residues (T) |
organic sulfur(S) |
Garlic extract (G) |
T × S |
|
|
G0 |
G1 |
|||
|
T0 |
S0 |
45.77 |
49.30 |
٤٧.٥٣ |
|
S1 |
52.77 |
52.10 |
٥٢.٤٣ |
|
|
S2 |
52.53 |
53.37 |
٥٢.٥٩ |
|
|
T1 |
S0 |
50.03 |
50.80 |
٥٠.٤٢ |
|
S1 |
51.73 |
53.30 |
٥٢.٥٢ |
|
|
S2 |
53.53 |
54.77 |
٥٤.١٥ |
|
|
T2 |
S0 |
52.97 |
53.60 |
٥٣.٢٨ |
|
S1 |
54.10 |
55.10 |
٥٤.٦٠ |
|
|
S2 |
65.20 |
59.30 |
٥٧.٧٥ |
|
|
L.S.D. 0.05 |
2.713 |
2.007 |
||
|
T × G |
T |
|||
|
T0 |
50.36 |
51.59 |
٥٠.٩٧ |
|
|
T1 |
51.77 |
52.96 |
٥٢.٣٦ |
|
|
T2 |
56.00 |
54.42 |
٥٥.٢١ |
|
|
L.S.D. 0.05 |
1.750 |
1.665 |
||
|
S × G |
||||
|
S0 |
49.59 |
51.23 |
٥٠.٤١ |
|
|
S1 |
52.87 |
53.50 |
٥٣.١٨ |
|
|
S2 |
54.09 |
55.81 |
٥٤.٩٥ |
|
|
L.S.D. 0.05 |
1.535 |
1.085 |
||
|
G |
52.18 |
53.51 |
||
|
L.S.D. 0.05 |
0.886 |
|||
Results of the two-way interaction between organic fertilizer and organic sulfur treatments showed that treatment T2S2 (30 tons ha-¹ + 600 kg ha-¹) recorded the highest height of 57.75 cm, compared to the lowest height in treatment T0S0 (0 tons ha-¹ + 0 kg ha-¹), which reached 47.53 cm. Regarding the two-way interaction between palm waste fertilizer and garlic extract, treatment T2G0 (30 tons ha-¹ + 0 ml L-¹) showed the highest plant height, recording 56.00 cm. Similarly, the interaction between organic sulfur and garlic extract had a significant positive effect, with treatment S2G1 (600 kg ha-¹ organic sulfur and 6 mL L-¹ garlic extract) recording a height of 55.81 cm.
The three-way interaction among all factors had the most notable impact. Treatment T2S2G0 achieved the maximum plant height (65.20 cm), while T0G0S0 treatment resulted in the shortest height at 45.77 cm.
Leaf area (dm²)
Results indicate that varying levels of date palm waste fertilizer led to a clear improvement in leaf area of green onion plants (Table 6). Treatment T1 recorded the highest value at 10.08 dm², significantly surpassing the control treatment T0, which showed the lowest leaf area at 8.90 dm². Fertilization with organic sulfur also resulted in a statistically significant increase in this trait: treatment S2 achieved the largest leaf area at 11.90 dm², compared to S0, which recorded only 8.06 dm². Regarding foliar application of garlic extract, treatment G1 outperformed G0, achieving a leaf area of 10.11 dm².
Concerning the two-way interaction between date palm waste and organic sulfur (T × S), treatment T2S2 stood out significantly, producing the greatest leaf area at 13.53 dm² in contrast to T0S0, which yielded the smallest value at 7.30 dm². The two-way interaction between palm waste and garlic extract (T × G) also showed significant superiority under treatment T2G1, which recorded a leaf area of 10.82 dm². Similarly, the interaction between organic sulfur and garlic extract (S × G) had a significant positive effect on leaf expansion, with treatment S2G1 achieving a leaf area of 12.76 dm².
As for the three-way interaction, the T2S2G1 treatment recorded the highest leaf area of 15.31 dm², while the T0S0G0 treatment gave the lowest leaf area of 6.90 dm².
These results confirm that each individual input contributes to leaf development, but the most substantial gains in photosynthetic surface area a key indicator of plant vigor and yield potential are achieved only through the synergistic integration of optimal levels of organic fertilizer, sulfur, and biostimulant. This underscores the value of holistic, integrated nutrient and biostimulant management in sustainable green onion production.
Table 6: Effect of fertilization with palm residues, organic sulfur, and garlic extract spray on leaf area (dm²)
|
palm residues(T) |
organic sulfur(S) |
Garlic extract (G) |
T × S |
|
|
G0 |
G1 |
|||
|
T0 |
S0 |
6.90 |
7.71 |
7.30 |
|
S1 |
9.29 |
8.42 |
8.86 |
|
|
S2 |
9.75 |
11.35 |
10.55 |
|
|
T1 |
S0 |
8.58 |
9.37 |
8.97 |
|
S1 |
9.28 |
10.03 |
9.65 |
|
|
S2 |
11.60 |
11.63 |
11.62 |
|
|
T2 |
S0 |
8.02 |
7.78 |
7.90 |
|
S1 |
7.77 |
9.37 |
8.57 |
|
|
S2 |
11.74 |
15.31 |
13.53 |
|
|
L.S.D. 0.05 |
0.935 |
0.661 |
||
|
T × G |
T |
|||
|
T0 |
8.65 |
9.16 |
8.90 |
|
|
T1 |
9.82 |
10.34 |
10.08 |
|
|
T2 |
9.18 |
10.82 |
10.00 |
|
|
L.S.D. 0.05 |
0.540 |
0.698 |
||
|
S × G |
||||
|
S0 |
7.83 |
8.29 |
8.06 |
|
|
S1 |
8.78 |
9.27 |
9.03 |
|
|
S2 |
11.03 |
12.76 |
11.90 |
|
|
L.S.D. 0.05 |
0.540 |
0.382 |
||
|
G |
9.21 |
10.11 |
||
|
L.S.D. 0.05 |
0.312 |
|||
Total yield (tons per hectare)
Results in Table 7 demonstrate that the application of date palm waste fertilizer had a clear and significant impact on the total yield of green onion plants. Treatment T2 (30 tons ha-¹) recorded the highest yield at 78.67 tons ha-¹, compared to treatment T0 (0 tons ha-¹), which had the lowest yield at 71.67 tons ha-¹. Organic sulfur fertilization also had a significant effect, with treatment S2 achieving 82.44 tons ha-¹ compared with 67.78 tons ha-¹ in S0. The effect of foliar spraying with garlic extract was evident in treatment G1, which recorded a total yield of 77.07 tons ha-¹ significantly higher than the unsprayed control (73.19 tons ha-¹).
Examining the two-way interaction between date palm waste and organic sulfur (T × S), treatment T2S2 achieved the highest total yield at 88.00 tons ha-¹, while the lowest yield (65.83 tons ha-¹) was recorded under T0S0. In the two-way interaction between palm waste and garlic extract (T × G), treatment T2G1 produced the highest yield at 79.56 tons ha-¹. Similarly, the interaction between organic sulfur and garlic extract (S × G) showed a strong positive effect, with treatment S2G1 achieving the highest yield in this interaction at 84.00 tons ha-¹.
The three-way interaction among the three factors resulted in treatment T2S2G1 (30 tons ha-¹ date palm residues, 600 kg ha-¹ organic sulfur, and 6 mL L-¹ garlic extract) producing the highest total yield at 89.33 tons ha-¹, while treatment T0S0G0 (no date palm residues, no organic sulfur, and no garlic extract) recorded the lowest total yield at 64.00 tons ha-¹.
Table 7: Effect of fertilization with palm residues, organic sulfur, and garlic extract spray on the total yield of green onion (t ha-¹)
|
palm residues(T) |
organic sulfur(S) |
Garlic extract (G) |
T × S |
|
|
G0 |
G1 |
|||
|
T0 |
S0 |
64.00 |
67.67 |
٦٥.٨٣ |
|
S1 |
69.00 |
75.00 |
٧٢.٠٠ |
|
|
S2 |
76.00 |
78.33 |
٧٧.١٧ |
|
|
T1 |
S0 |
67.33 |
68.67 |
٦٨.٠٠ |
|
S1 |
69.00 |
81.00 |
٧٥.٠٠ |
|
|
S2 |
80.00 |
84.33 |
٨٢.١٧ |
|
|
T2 |
S0 |
69.00 |
70.00 |
٦٩.٥٠ |
|
S1 |
77.67 |
79.33 |
٧٨.٥٠ |
|
|
S2 |
86.67 |
89.33 |
٨٨.٠٠ |
|
|
L.S.D. 0.05 |
7.499 |
5.789 |
||
|
T × G |
T |
|||
|
T0 |
69.67 |
73.67 |
٧١.٦٧ |
|
|
T1 |
72.11 |
78.00 |
٧٥.٠٦ |
|
|
T2 |
77.78 |
79.56 |
٧٨.٦٧ |
|
|
L.S.D. 0.05 |
5.234 |
5.157 |
||
|
S × G |
||||
|
S0 |
66.78 |
68.78 |
٦٧.٧٨ |
|
|
S1 |
71.89 |
78.44 |
٧٥.١٧ |
|
|
S2 |
80.89 |
84.00 |
٨٢.٤٤ |
|
|
L.S.D. 0.05 |
4.080 |
2.885 |
||
|
G |
73.19 |
٧٧.٠٧ |
||
|
L.S.D. 0.05 |
2.356 |
|||
Discussion
From the results of the above tables (1, 2, 3, 4, 5, 6, 7), we conclude that adding palm waste fertilizer has a positive role in increasing nutrients, chlorophyll, vegetative characteristics and total yield in green onions by improving The soil’s physical and chemical characteristics, including increasing the organic matter level and enhancing the ability of soil’s to retain water, which positively affects growth and productivity. Similar findings were reported by (Alshamary et al., 2023), who observed that incorporating 5% palm residues into the soil significantly improved total yield, leaf area, chlorophyll content, and nutrient accumulation in onion compared with untreated soil. Fertilization with palm residues also promotes the activity of beneficial soil microorganisms and enriches soil with essential nutrients such as nitrogen, phosphorus, and potassium (Kavvadias et al., 2024). The decomposition of organic matter further contributes to the formation of amino and organic acids that play a vital role in plant physiological processes and in stimulating the synthesis of secondary metabolites, thereby positively affecting crop yield (Ismail, 2017). These results are consistent with (Fahrurrozi et al., 2022), who found that liquid organic fertilizer enhanced vegetative and qualitative traits of green onion, and with (Liu et al., 2024), who demonstrated that organic fertilization increased soil sulfur content, consequently improving sulfur compound formation in onion and enhancing productivity.
The observed improvements in vegetative traits associated with organic sulfur application reflect the essential role of sulfur in plant growth. Sulfur is a key element in protein synthesis through its incorporation in amino acids, especially Cysteine and Methionine which are fundamental sulfur-containing amino acids and serve as building blocks for protein formation (Brosnan and Brosnan., 2006). Additionally, sulfur contributes to the formation of disulfide (S–S) linkages between amino acids such as glutamic acid and glycine, and it plays a central role in the synthesis of Coenzyme A (CoA-SH), vitamins, and ferredoxin. The latter acts as a strong reducing agent and an essential component of the electron transport chain during the light reactions of photosynthesis (González-Morales et al., 2017).
Positive results above related to spraying with garlic extract may be due to the fact that organic plant extracts contribute to deeper root penetration into the soil, which positively affects the plant’s efficiency in nutrient uptake. They also increase soil organic carbon, which enhances the content and activity of soil microorganisms, promoting nitrate reduction and nitrogen absorption by the plant (Bar et al., 2022). In addition, Organic plant extracts may help promote growth and enhance leaf mineral elements content because it contains rich in elements and amino acids (Ismail, 2017). Moreover, increase of these characters could be due to the role played by substances in garlic extract which function as biostimulants like growth promoting hormones, such as auxins and gibberellins and salicylates which activates and promote photosynthesis in plants. It directly promotes plant growth and enhances the concentration of bioactive compounds (Golubkina et al., 2024; Hayat et al., 2022), thus increasing nutritional quality and yield. Moreover, the enhancement of studied traits following application of garlic spray may result from abundance of the polyphenols in garlic which serve as pre-activated compounds when extract is sprayed to the plant (Ei et al., 2024; Golubkina et al., 2022). The extract also promotes the induction of antioxidant activity (Hamza et al., 2024), enhancing the plant’s overall health and enhancing its characteristics (Ali et al., 2019).
Conclusions
Simultaneous application of palm residues, organic sulfur and garlic extracts showed distinct synergistic behavior on growth, yield and chemical composition of green onion. The palm residues enhanced the soil fertility and water holding capacity, organic sulfur improved protein and enzyme synthesis, and garlic extract formed a natural biostimulant. These combined implications substantially enhanced N, P and S accumulation in bulb, the chlorophyll content of leaves, vegetative growth characters (i.e., plant height and leaf area), which ultimately lead to increasing marketable yield. These results support the implementation of sustainable fertilization practices with organic resources as substitutes to chemical inputs, that could contribute both to sustainability in agriculture and production of safety and nutritional food. The results provide a basis for the application of sustainable fertilization with organic materials as an alternative to the use of chemical inputs and for sustainable agriculture, safe healthy food production.
Acknowledgement
The author acknowledges the Dean of College of Agricultural Engineering Sciences and the Head of the Department of Horticulture and Landscape Engineering Universitas Baghdad for providing facilities and time for this research.
Novelty Statement
This study is the first, to our knowledge, to integrate the use of organic fertilizers for date palms and sulfur with garlic extract to improve the growth and productivity of green onions under sustainable farming conditions.
Author’s Contribution
Elaf Hamza Wali: fieldwork, sowing, harvesting; wrote abstract, introduction, data collection, data entry in GenStat and analysis, results and discussion, conclusion and references.
Yasamen Fadhil Saloom: Editing of draft, supervised the research, analyzed data, reviewed the manuscript, proofread, reviewed the manuscript, Overall Management of the article, performed proof-reading, and revised the manuscript.
Generative AI and AI-assisted technology statement
The authors declare that no generative AI and AI assisted technology was used in the creation of this manuscript.
Conflict of interest
The authors have declared no conflict of interest
References
Abdel-Hakim, Y. 2020. The Essential Guide to Fertilizers and Fertilization (Plant Nutrition Physiology), 38–40.
Akbar, F., N. Ahmed, M. Mussarat, I. Ahmed, D. Muhammad, T. Ahmad, M.A. Akbar, S. Rafique, S. Ali, S. Aslam, B.H. Shah, F. Ahmad and M.A. Khan. 2024. Effect of trichoderma applied with different sulfur levels on yield and sulfur uptake by onion (Allium cepa L.). Sar. J. Agric., 40(2): 286–294. https://doi.org/10.17582/journal.sja/2024/40.2.286.294
Al-Amri, B.K.F. and M.M.M. Al-Abdaly. 2021. Effect of adding sulfur and organic fertilizer on growth and yield of onions (Allium cepa L.) under different plant densities. IOP Confer. Ser.: Earth Environ. Sci., 910(1): 012059. https://doi.org/10.1088/1755-1315/910/1/012059
Al-Hajj, A.H.A., Y.A. Al-Areqi and A.M. Eid. 2022. Effect of spraying different concentrations of garlic clove aqueous extract on floral growth and yield of cucumber (Cucumis sativus L. cv. Alpha Beit) under the climatic conditions of Ibb City, Yemen. Arab J. Scient. Res., 1–6
Al-Hlfie, R.G. and W.A. Hussein. 2024. Effect of organic fertilizers and nutrients on anatomical traits of red beetroots. Iraqi J. Agric. Sci., 55(Special Issue): 151–161. https://doi.org/10.36103/ijas.v55iSpecial.1894
Ali, M., A. Muhammad, Z. Cheng, H. Sikandar, A. Husain, I. Muhammad, and T. Liu. 2019. Foliar spraying of aqueous garlic bulb extract stimulates growth and antioxidant enzyme activity in eggplant (Solanum melongena L.). J. Integrat. Agric., 18(5): 1001–1013. https://doi.org/10.1016/S2095-3119(18)62129-X
Ali, W.M., S.M.E. Sultan, A.M. Ali, H.M. Al-Sayed, M.A. Mahmoud, H.G. Ismail, I.I. Teiba and A.F. Yousef. 2025. Organic fertilizers and Azotobacter: effects on onion growth, yield, metabolites, and soil fertility. AMB Express., 15(1): 86. https://doi.org/10.1186/s13568-025-01895-5
Al-Mousawi, Z.J., Y.F. Saloom, and Z.M. Abdul-Qader. 2024. Evaluation of foliar spray with extract of marine algae and yeast and mowing date on growth, yield, and active components of watercress. Iraqi J. Agric. Sci., 55(1): 459–469 https://doi.org/10.36103/6310fv68.
Alshamary, W.F.A., E.T. Abdel Ghani, B.A.A.H. Alkhateb, and J.Sh. Eyada. 2023. The effect of adding date palm residues, irrigation water and humic acids on onion yield and water consumption (Allium cepa L.). Conference Paper (Minar Congress)
Amare, G. 2020. Review on Mineral Nutrition of Onion (Allium cepa L). Open Biotechnol. J., 14: 134 https://doi.org/10.2174/1874070702014010134
Aram, S.A.M. and M.M.S. Khattab. 2018. An economic study on utilizing by-products of date palm (case study in Al-Sharqia and Qalyubia governorates). Egypt. J. Agric. Econom., 28(4): 1–18.
Asha, Diksha, Shabnam, P. Sanwal, S. Dagar and H. Dagar. 2023. Impact of organic farming practices on soil organic matter: A Review. Int. J. Plant Soil Sci., 35(19): 1599–1603. https://doi.org/10.9734/ijpss/2023/v35i193705
Bar, M., U.E Binduga. and K.A. Szychowski. 2022. methods of isolation of active substances from garlic (Allium sativum L.) and its impact on the composition and biological properties of garlic extracts. Antioxidan., 11(7): 1345. https://doi.org/10.3390/antiox11071345
Brosnan, J.R. and M.E. Brosnan. 2006. The sulfur-containing amino acids: An overview. J. Nutrit., 136(6 Suppl): 1636S–1640S. https://doi.org/10.1093/jn/136.6.1636S
Bulgari, R., G. Franzoni, and A. Ferrante. 2019. Biostimulants application in horticultural crops under abiotic stress conditions. Agron., 9(306): 1–30. https://doi.org/10.3390/agronomy9060306
Demissie, D.S. and A. Shiferaw. 2024. Effect of nitrogen fertilizer and poultry manure on the yield and yield components of onion (Allium cepa L.) in Alage, East Shewa, Ethiopia. Front., 4(1): 29–41. https://doi.org/10.11648/j.frontiers.20240401.15
Desouza, L., A.B.C. Filho, F.A. DeTulio, and R.H.D. Nowaki. 2015. Effect of sulfur dose on the productivity and quality of onion. Austral. J. Crop Sci., 9(8): 728–733. https://doi.org/10.1088/1755-1315/1214/1/012012.
Du, S., M.Zhen J. Chen, L. Xue, C. Tang, T.M.E. Shareef, and K.H.M. Siddique. 2022. Effects of organic fertilizer proportion on the distribution of soil aggregates and their associated organic carbon in a field mulched with gravel. Scient. Report., 12(1): 11513. https://doi.org/10.1038/s41598-022-15110-z
Ei, E., H.H. Park, and Y.I. Kuk. 2024. Effects of plant extracts on growth promotion, antioxidant enzymes, and secondary metabolites in rice (Oryza sativa L.) plants. Plant., 13(19): 2727 https://doi.org/10.3390/plants13192727.
Elsahooki, M.M. and K. Waheeb. 1990. Applications in Experimental Design and Analysis. Mosul, Iraq: Dar Al-Hikma Publishing. p: 488
Fahrurrozi, F., Z. Muktamar, N. Setyowati, and S. Sudjatmiko. 2022. Liquid organic fertilizer increased nutrient uptakes, growth and yields of organically grown carrot and green onion. Asian J. Plant Sci., 21: 707–715. DOI: https://dx.doi.org/10.3923/ajps.2022.707.715
Fayhaa, M.N., H.T. Ibrahim, R.A.A. Alsahoo, I.A. Jihad, R.M.A.Z. Qais .2025. oRGINAL article. J. Anim. Health Prod., 13(s1): 39–48. https://dx.doi.org/10.17582/journal.jahp/2024/13.s1.39.48
Gamiely, S., W.M. Randle, H.A. Mills, and D.A. Smittle. 1991. A rapid and nondestructive method for estimating leaf area of onion. Hort Sci., 26(2): 206 https://doi.org/10.21273/HORTSCI.26.2.206
Ghouili, E., G. Abid, R. Hogue, T. Jeanne, J. D’Astous-Pagé, K. Sassi, Y. Hidri, H.C. M’Hamed, A. Somenahally, Q. Xue, M. Jebara, R.N. Ouertani, J. Riahi, A.C. de Oliveira, and Y. Muhovski. 2023. Date Palm Waste Compost Application Increases Soil Microbial Community Diversity in a Cropping Barley (Hordeum vulgare L.) Field. Biol., 12(4): article 546. https://doi.org/10.3390/biology12040546
Golubkina, N., V. Kharchenko, A. Moldovan, M. Antoshkina, O. Ushakova, A. Sękara, V. Stoleru, O.C. Murariu, A.V. Tallarita, M. Sannino and G. Caruso. 2024. Effect of selenium and garlic extract treatments of seed-addressed lettuce plants on biofortification level, seed productivity and mature plant yield and quality. Plant., 13: 1190. https://doi.org/10.3390/plants13091190
Golubkina, N., V. Zayachkovsky, S. Sheshnitsan, L. Skrypnik, M. Antoshkina, A. Smirnova, M. Fedotov, and G. Caruso. 2022. Prospects of the application of garlic extracts and selenium and silicon compounds for plant protection against herbivorous pests: A review. Agric., 12(1): 64 https://doi.org/10.3390/agriculture12010064.
González-Morales, S., F. Pérez-Labrada, E.L. García-Enciso, P. Leija-Martínez, J. Medrano-Macías, I.E. Dávila-Rangel, A. Juárez-Maldonado, E.N. Rivas-Martínez and A. Benavides-Mendoza. 2017. selenium and sulfur to produce allium functional crops. Molecul., 22(4): 558. https://doi.org/10.3390/molecules22040558
Goodwin, T.W. 1976. Chemistry and Biochemistry of plant pigment .2nded. Academic. Press. London. New York. San Francisco. p373
Hamza, R.K., N.N. Hamed and H.S.J. Al-Mazirah. 2024. The effects of spraying with onion and garlic extracts on the growth of the plant Anethum graveolens L. and its antioxidant effectiveness. Acta Agraria Debreceniensis., 2024-2. https://doi.org/10.34101/actaagrar/2/13501
Hayat, S., A. Ahmad, H. Ahmad, K. Hayat, M.A. Khan and T. Runan. 2022. Garlic, from medicinal herb to possible plant bioprotectant: A review. Sci. Hortic., 304: 111296. https://doi.org/10.1016/j.scienta.2022.111296
He, H., J.L. Xia, H.C. Jiang, Y. Yan, C.L. Liang, C.Y. Ma, L. Zheng, Y.D. Zhao, and G.Z. Qiu. 2010. Sulfur species investigation in extra- and intracellular sulfur globules of Acidithiobacillus ferrooxidans and Acidithiobacillus caldus. J. Geomicrobiol., China University 27: 707–713. DOI: https://dx.doi.org/10.1080/01490451003597655
Ismail, A.E. 2017. Impact of Azolla caroliniana and A. pinnata as soil amendments on Rotylenchulus reniformis and plant growth of cowpea in Egypt. Advan. Agric. Sci., 5, 02: 10-14
Jackson, M.L. 1958. Soil Chemical analysis. Prentice Hall, Inc. Englewood Cliff, N.J. USA. 225-276
Javed, A. 2025. Plants as a Source of Bioactive Compounds. Food Analys. Proper. Ser. Chapter., pp:15. DOI: https://dx.doi.org/10.1201/9781003462804-3.
Kavvadias, V., E. Le Guyader, M. El Mazlouzi, M. Gommeaux, B. Boumaraf, M. Moussa, H. Lamine, M. Sbih, I.R. Zoghlami, K. Guimeur, et al. 2024. Using Date Palm Residues to Improve Soil Properties: The Case of Compost and Biochar. Soil Sys., 8(3): article 69. https://doi.org/10.3390/soilsystems8030069
Khorsheed, A.A. and J.Y.A. Al-Tamimi. 2018. Effect of nitrogen and sulfur fertilization levels on growth and yield of onion (Allium cepa L.). Tikrit J. Agric. Sci., 18(1): 89–98.
Kim, S.H., J.B. Yoon, J. Han, Y.A. Seo, B.-H. Kang, J. Lee, and K. Ochar. 2023. Green onion (Allium fistulosum): An aromatic vegetable crop esteemed for food, nutritional and therapeutic significance. Food., 12: 4503. https://doi.org/10.3390/foods12244503
Le Guyader, E., X. Morvan, V. Miconnet, B. Marin, M. Moussa, D.S. Intrigliolo, M.J. Delgado-Iniesta, P. Girods, S. Fontana, M. Sbih, B. Boumaraf, A. Tirichine, V. Kavvadias and M. Gommeaux. 2024. Influence of Date Palm-Based Biochar and Compost on Water Retention Properties of Soils with Different Sand Contents. Forest., 15(2): 304. https://doi.org/10.3390/f15020304
Liu, X., J. Guo, Z. Chen, K. Xu and K. Xu. 2024. Detection of volatile compounds and their contribution to the nutritional quality of Chinese and Japanese Welsh onions (Allium fistulosum L.). Hortic., 10(5): 446. https://doi.org/10.3390/horticulturae10050446
Liu, Y., X. Lan, H. Hou, J. Ji, X. Liu and Z. Lv. 2024. Multifaceted ability of organic fertilizers to improve crop productivity and abiotic stress tolerance: review and perspectives. Agron., 14(6): 1141. https://doi.org/10.3390/agronomy14061141
Lorin. Z. Al-sarragi and Ayad. W. A. Aljuboori. 2022. Effect of Bio-fertilizers and Boron Spray on Growth and Yield of Onion. Neuro. Quantol., 20(6): 6788-6795
Mahmood, N., M.A. Muazzam, M. Ahmad, S. Hussain, and W. Javed. 2021. Phytochemistry of (Allium cepa L.) (Onion): An Overview of its Nutritional and Pharmacological Importance. Scient. Inquiry Rev., (SIR), 5(3): 41–49. https://doi.org/10.32350/sir/53.04
Maitig, F.M., A.A.K. Alasifer, H.A. Algaied, H.A.M. Emesh, and A. Ben Wafa. 2025. Growth and biochemical response of basil to foliar-applied garlic extract. DYSONA – Appl. Sci., 6: 120–125.
Manik, M.M.H., M.A. Razzaque, M.I. Haque, M.R.K. Joha, K. Syfullah, A.A. Khanam, M.S. Reza and S.N. Afrose. 2024. Effect of different levels of potassium and sulfur fertilizers on growth and yield of onion (Allium cepa L.). Asian J. Agric. Allied Sci., 7(1): 33-40. https://doi.org/10.56557/ajaas/2024/v7i140
Mohammed, M.D., T.K. Karyagdi, A.M. Qneed, I.A. Jihad, Q.R. Lahhob, M. Mudhafar, H.A. Alsailawi, & A.A. Ayada. 2025. Molecular characterization and zoonotic potential of giardia species in livestock with respect to their transmission dynamics and host adaptation. J. Anim. Health Prod., 13(s1): 411–421. https://dx.doi.org/10.17582/journal.jahp/2025/13.s1.411.421
Muslat, M.M. and S.A. Salih. 2017. Effect of fertilization with date palm waste on growth and yield traits of cucumber under protected conditions. Anbar J. Agric. Sci., 51(1): 181–190.
Ogunbode, A.A. and K.O. Tijani. 2020. Effect of different level of potassium and sulfur fertilizers on growth and yield of onion (Allium cepa L.). Asian J. Agric. Allied Sci., 14(2): 40–43.
Olsen, S.R. and L.E. Sommers. 1982. Phosphorus in A.L Page, (Ed). Methods of soil analysis. Part2. Chemical and Microbiological properties 2nd edition, Amer. Soc. Agron. Inc. Soil Sci. Soc. Amer. Inc. Madision Wis., U.S.A https://doi.org/10.2134/agronmonogr9.2.2ed.c24
Sable, P.A., S.K. Acharya, J.J. Mistry, and P. Verma. 2024. Effect of potash and sulphur levels on growth, yield, quality parameters and economics in onion. Int. J. Res. Agron., 7(3): 567–571. https://doi.org/10.33545/2618060X.2024.v7.i3h.478
Shaker, U.B. and I.J. Abdul Rasool. 2023. Role of organic fertilizer and boron foliar application on growth and productivity of potato for processing. Iraqi J. Agric. Sci., 54(5): 1478–1486. https://doi.org/10.36103/ijas.v54i5.1847
Sunanta, P., V. Kontogiorgos, T. Pankasemsuk, K. Jantanasakulwong, P. Rachtanapun, P. Seesuriyachan and S.R. Sommano. 2023. The nutritional value, bioactive availability and functional properties of garlic and its related products during processing. Front. Nutrit., 10: Article 1142784. https://doi.org/10.3389/fnut.2023.1142784
Taru, A.S., B.R. Tijare and J.R. Wadkar. 2025. Effect of sulphur on onion bulb production under frontline demonstrations in Buldhana District of Maharashtra. Int. J. Res. Agron., SP-8(1): 230–233. https://doi.org/10.33545/2618060X.2025.v8.i1Sd.2378
Tilahun, D., A. Tena, and B. Desta. 2021. Effects of different nitrogen and sulfur fertilizer rates on growth, yield, quality and nutrient uptake of onion (Allium cepa L.) at Chewa Robit, Northern Shewa Ethiopia. Open Biotechnol. J., 15: 59–67. https://doi.org/10.2174/1874070702115010059
Williams, C.H. and Steinbergs, A. 1959. Soil sulphur fractions as chemical indices of available sulphur in some Australian soils. Aust. J. Agric. Res., 10: 340 – 352 https://doi.org/10.1071/AR9590340
Zhao X.X., F.J.H. Lin, H.B. Li Li, D.T. Wu, F. Geng, W. Ma, Y. Wang, B.H. Miao and R.Y Gan. 2021. Recent Advances in Bioactive Compounds, Health Functions, and Safety Concerns of Onion (Allium cepa L.). Front. Nutr., 8: 669805. doi: https://dx.doi.org/10.3389/fnut.2021.669805