Effect of biostimulant on growth, yield and quality of green chilli (Capsicum annuum)

Introduction

Vegetables are essential components of the human diet, providing carbohydrates, proteins, vitamins, minerals and antioxidants that promote health and protect against diseases. In India, the per capita daily availability of vegetables is about 237 g, which is considerably lower than the recommended 350 g per person per day (ICMR, 2019). Enhancing vegetable production and productivity is therefore crucial for ensuring nutritional security. India, the second-largest producer of vegetables globally after China, produces nearly 200 million metric tons annually from about 11.28 million hectares. Major producing states include Uttar Pradesh, West Bengal, Madhya Pradesh, Bihar and Maharashtra (Jha et al., 2019) [17] . Among vegetable crops, chilli (Capsicum annuum L.) holds great economic and nutritional importance. Belonging to the Solanaceae family, chilli is cultivated across tropical and subtropical regions, though it is less suited to temperate climates. The genus Capsicum comprises about 30 species, of which five (C. annuum, C. frutescens, C. chinense, C. pubescens and C. baccatum) are widely cultivated (Bosland & Votava, 2000) [6] . Native to Tropical America and introduced to India in the 16th century (Pruthi, 1976) [26] , chilli is consumed both as fresh green fruits and as dried spice. The fruits are rich in vitamins A and C, thiamine, folate, potassium, carotenoids, flavonoids and dietary fiber (Lee & Kader, 2000 [21] ; Chuah et al., 2008) [9] . Capsaicin, the pungent principle, has pharmaceutical applications, while capsanthin, the red pigment, is used as a natural food colorant.

Despite its high demand, chilli productivity is often limited by poor nutrient use efficiency, abiotic stress and pest disease incidence. Heavy dependence on chemical fertilizers and pesticides also poses environmental concerns. In this context, biostimulants have emerged as sustainable inputs to enhance growth, yield and quality. Biostimulants are substances or microorganisms that stimulate natural plant processes to improve nutrient uptake, stress tolerance and productivity, without being direct sources of nutrients (Traon et al., 2014) [32] . Different categories of biostimulants are in use, including humic and fulvic acids, seaweed extracts, amino acids and traditional formulations like Panchagavya and Jivamrut. Humic and fulvic acids enhance photosynthesis, root growth, nutrient absorption and stress resilience (Aikpo et al., 2024). Seaweed extracts, derived mainly from brown algae, contain bioactive compounds and growth regulators that improve flowering, yield, chlorophyll content and stress tolerance (Godlewska et al., 2016 [12] ; Ali et al., 2021). Amino acids are readily absorbed through leaves and support photosynthesis, nutrient transport, flowering and stress resistance (Naroozlo et al., 2019) [23] . Panchagavya, prepared from cow-based products and Jivamrut, a fermented biofertilizer, are rich in growth-promoting substances, enzymes and beneficial microbes that improve plant vigor, immunity and productivity (Selvaraj et al., 2007 [29] ; Dhama et al., 2017) [11] . Given their potential, foliar application of biostimulants may serve as an eco-friendly strategy to boost chilli growth and yield while reducing reliance on synthetic inputs. However, their efficacy depends on concentration, crop type and field conditions. Therefore, the present study was undertaken with the following objectives: 1. To study the effect of biostimulants on growth parameters of chilli. 2. To study the effect of biostimulants on yield and quality parameters of chilli.

Materials and methods

T1

Amino acid based (isabion) @ 2 ml / liter T2 Amino acid based (isabion) @ 3 ml / liter T3 Humic + fulvic acid (Humiffco) @ 2.5 ml / liter T4 Humic + fulvic acid (Humiffco) @ 3.5 ml / liter T5 Panchagavya @ 15 ml/ liter T6 Panchagavya @ 25 ml/ liter T7 Seaweed extract ( Biozyme crop +) @ 3ml / liter T8 Seaweed extract ( Biozyme crop +) @ 5 ml / liter T9 Jivamrut @ 15 ml / liter T10 Jivamrut @ 25 ml / liter

Results and discussion

The present study investigated the influence of foliar biostimulants on the growth, yield and quality of chilli cv. PBNC-17 under field conditions. The results obtained are presented under the following sub-headings, supported by statistical analysis and relevant literature.

Significant variation in plant height was observed among treatments (Table 2). Maximum height was recorded in T2 (Amino acid @ 3 ml/l), with 65.69 cm at final harvest, statistically at par with T1 (Amino acid @ 2 ml/l, 64.13 cm).

Treatments with humic + fulvic acid (T3 and T4) also performed well, recording 62.50 cm and 60.57 cm respectively. The lowest height was recorded in T9 (Jivamrut @ 15 ml/l, 55.65 cm). The improvement in plant height under amino acid treatments may be attributed to enhanced protein synthesis, chlorophyll formation and hormonal activity (Shazia et al., 2021 [30] ; Jan et al., 2020) [16] . Similar results were reported by Ruban et al. (2019) [27] in brinjal and Baloch et al. (2014) [4] in chilli, confirming the growth-promoting role of amino acids.

Biostimulant application also significantly influenced stem girth (Table 3). Maximum girth was obtained in T4 (Humic + fulvic acid @ 3.5 ml/l), with 9.52 mm at harvest, followed by T8 (Seaweed extract @ 5 ml/l, 9.13 mm). Minimum girth was recorded in T1 (Amino acid @ 2 ml/l, 7.88 mm). The positive effect of humic and fulvic acids on stem diameter may be linked to improved nutrient absorption and hormonal activity, as also reported by Abdel-Mawgoud et al. (2007) [1] in green beans.

Number of branches per plant

Branching was significantly enhanced by amino acid treatments (Table 4). T2 recorded the maximum (11.50 branches), at par with T1 (11.17), followed by T4 (10.05).

The minimum number of branches was noted in T9 (8.00). Amino acids stimulate cytokinin activity and cell division, leading to enhanced branching (Deori et al., 2023) [10] .

Number of leaves per plant

T2 (Amino acid @ 3 ml/l) recorded the maximum leaf count (170.01), followed closely by T1 (167.74) and T3 (152.60). The minimum leaf production was observed in T9 (125.51).

Increased leaf area due to amino acids and humic substances has been linked to enhanced photosynthesis and assimilation, in agreement with Kiran et al. (2021) [19] in chilli and Avinash et al. (2017) [3] in capsicum.

Flowering Characteristics Number of flowers per plant

Biostimulant treatments significantly influenced flower production (Table 6). The maximum flowers per plant were recorded in T2 (Amino acid @ 3 ml/l, 129.72), statistically at par with T1 (124.42) and T7 (Seaweed @ 3 ml/l, 119.43).

The minimum number was recorded in T9 (Jivamrut @ 15 ml/l, 89.05). Amino acids promote floral initiation by enhancing metabolic activity and protein synthesis, while seaweed extracts supply cytokinins and auxins that support floral differentiation. Similar findings were reported by Ali et al. (2021) [2] in tomato and sweet pepper using seaweed extract.

The highest fruit set was recorded in T10 (Jivamrut @ 25 ml/l, 55.68%), at par with T9 (53.90%) and T3 (Humic + fulvic acid @ 2.5 ml/l, 53.19%). The lowest fruit set occurred in T2 (Amino acid @ 3 ml/l, 48.95%). The superior performance of Jivamrut could be due to its microbial consortia and growth-promoting metabolites that enhance pollination success and fruit initiation. Comparable outcomes were noted by Premprakash Singh et al. (2021) [25] in tomato with Jeevamrut sprays and Bharadwaj et al.

(2023) in okra. (2022) [15] in okra.

Table 7: Effect of biostimulant on flower drop

Treatment

Flower drop % per plant T1-Amino acid @ 2ml/lit 50.62 T2-Amino acid @ 3ml/lit 51.05 T3-Humic acid + fulvic acid @ 2.5 ml/liter 46.81 T4-Humic acid + fulvic acid @ 3.5 ml/liter 47.59 T5-Panchagavya @ 15 ml/lit 46.96 T6-Panchagavya @ 25 ml/lit 48.09 T7-Sea weed @ 3ml/lit 50.94 T8-Sea weed @ 5ml/lit 48.98 T9-Jivamrut @ 15 ml/lit 46.01 T10-Jivamrut @ 25 ml/lit 44.32 SE + 1.31 CD at 5% 3.91

Days to flowering and harvest

Earliness was promoted by humic + fulvic acid treatments. T4 (3.5 ml/l) recorded the earliest flowering (34.09 days), 50% flowering (39.41 days) and first harvest (65.00 days), significantly earlier than T5 (Panchagavya @ 15 ml/l), which showed delayed flowering (41.73 days) and harvest (70.90 days). Humic and fulvic acids are known to enhance nutrient uptake and hormonal signaling, accelerating phenological events (Jan et al., 2020 [16] ; Honnapa et al., 2025) [14] . [24] in chilli.

The maximum fruit yield per plant was observed in T2 (208.00 g), followed by T1 (203.02 g) and T7 (196.77 g).

The minimum was in T9 (173.30 g). Khan et al. (2018) [18] also reported increased fruit yield in bell pepper with amino acid sprays, while Chauhan et al. (2023) [7] demonstrated the role of seaweed extract in increasing pod yield in okra.

Fruit yield per treatment and hectare T2 recorded the maximum yield per treatment (2.08 kg) and per hectare (74.28 q/ha), significantly superior to Jivamrut (T9: 61.78 q/ha; T10: 62.50 q/ha) and Panchagavya (T5: 63.91 q/ ha). These results confirm the efficiency of amino acid formulations in boosting yield, supported by Chooneea et al. (2009) [8] who demonstrated amino acid stimulants enhanced chilli yield and Bawya et al. (2025) [5] who found combined seaweed + humic sprays improved cluster bean productivity. 11). Minimum aphid incidence was in T10 (10.00%) and T9 (13.33%), while maximum was in T2 (36.66%).

Thrips incidence was also lowest in T5, T6 and T10 (13.33%). The effectiveness of Jivamrut and Panchagavya may be due to bioactive compounds and microbial metabolites that repel or suppress pests. Hameedi et al.

(2022) [13] reported reduced pest incidence in bell pepper under organic biostimulant regimes and Vidanapathirana et al. (2021) [33] found panchagavya reduced pest-damaged leaves in capsicum.

Disease incidence (anthracnose and leaf curl)

Anthracnose incidence was lowest in T5, T6 and T10 (10.00%), while maximum was in T3 and T7 (20.00%).

Leaf curl incidence was minimized in T6 and T10 (16.66%) but maximum in T1 (40.00%). These results align with Lekshmi (2011) [22] , who reported reduced chilli disease incidence with organic formulations and Sugandhika et al.

(2021) [31] , who highlighted seaweed extracts in capsicum for enhancing disease tolerance.

Quality Attributes Chlorophyll content

Amino acid sprays recorded the highest chlorophyll content (T2: 51.90 SPAD; T1: 51.85 SPAD), while the lowest was in Jivamrut (T9: 30.00; T10: 30.13 SPAD). Amino acids play a direct role in chlorophyll synthesis and photosynthetic activity, as also shown by Sayaf et al. (2024) [28] in chilli. Seaweed (T7, T8) and humic acid treatments (T3, T4) showed moderate improvement. Kumar et al.

(2023) [20] reported similar findings with Ascophyllum nodosum extract in okra, confirming the role of seaweed in enhancing photosynthesis.

Treatment

Chlorophyll (SPAD) T1-Amino acid @ 2ml/lit 51.85 T2-Amino acid @ 3ml/lit 51.90 T3-Humic acid + fulvic acid @ 2.5 ml/lit 41.44 T4-Humic acid + fulvic acid @ 3.5 ml/lit 46.68 T5-Panchagavya @ 15ml/lit 33.00 T6-Panchagavya @ 25 ml/lit 33.99 T7-Sea weed @ 3ml/lit 37.11 T8-Sea weed @ 5ml/lit 40.00 T9-Jivamrut @ 15 ml/lit 30.00 T10-Jivamrut @ 25 ml/lit 30.13 SE + 1.67 CD at 5% 4.97

Conclusion

The application of foliar biostimulants significantly influenced the growth, flowering, fruiting, pest and disease management and overall productivity of chilli cv. PBNC-17. Among all treatments, the following conclusions were drawn:  T2 (Amino acid @ 3 ml/lit) emerged as the most promising treatment across a broad range of parameters, including plant height, branching, flower number, fruit count, yield per plant and total yield per hectare.  T4 (Humic acid + fulvic acid @ 3.5 ml/lit) was effective in promoting early flowering and harvesting, as well as improving stem girth.  T10 (Jivamrut @ 25 ml/lit) demonstrated its potential in minimizing pest and disease incidence and improving fruit set percentage.  Seaweed extracts (T7 and T8) exhibited moderate effectiveness across most growth and yield parameters.  Panchagavya treatments (T5 and T6) showed limited impact on growth and yield but contributed to disease resistance.

References

1. Abdel-Mawgoud AMR, El-Greadly NHM, Helmy YI, Singer SM. Responses of tomato plants to different rates of humic-based fertilizer and NPK fertilization. Journal of Applied Sciences Research. 2007;3(2):169174.
2. Ali O, Ramsubhag A, Jayaraman J. Biostimulant properties of seaweed extracts in plants: Implications towards sustainable crop production. Plants. 2021;10(3):531.
3. Avinash K, Patil AA, Chavan SA. Effect of biostimulants on growth and yield of capsicum. International Journal of Chemical Studies. 2017;5(6):1430-1433.
4. Baloch QB, Chachar QI, Tareen MN. Effect of foliar application of amino acids and mineral nutrients on fruit set and yield of chilli (Capsicum annuum L.). Pakistan Journal of Agriculture, Agricultural Engineering and Veterinary Sciences. 2014;30(2):131138.
5. Bawya V, Prakash M, Kannan M. Combined effect of seaweed extract and humic acid on cluster bean productivity. Journal of Pharmacognosy and Phytochemistry. 2025;14(1):123-128.
6. Bosland PW, Votava EJ. Peppers: Vegetable and spice capsicums. CABI Publishing; 2000.
7. Chauhan A, Sharma S, Singh R. Influence of seaweed extract on growth and yield of okra (Abelmoschus esculentus L.). International Journal of Agricultural Sciences. 2023;19(1):45-50.
8. Chooneea N, Sinzogan A, Ragoonath C. Effect of amino acid stimulant on yield and quality of chilli (Capsicum annuum L.). Agricultural Science Digest. 2009;29(2):90-94.
9. Chuah AM, Lee YC, Yamaguchi T, Takamura H, Yin LJ, Matoba T. Effect of cooking on the antioxidant properties of coloured peppers. Food Chemistry. 2008;111(1):20-28. https://doi.org/10.1016/j.foodchem.2008.03.022.
10. Deori C, Sharma R, Hazarika TK. Effect of amino acids on vegetative growth and yield of brinjal. Journal of Pharmacognosy and Phytochemistry. 2023;12(2):11901194.
11. Dhama K, Latheef SK, Dadar M, Samad HA, Munjal A, Khandia R, et al. Biomaterials and bioformulations: Sustainable applications in crop production and protection. International Journal of Current Research. 2017;9(7):54006-54015.
12. Godlewska K, Michalak I, Tuhy Å, Chojnacka K. Plant growth biostimulants based on different methods of seaweed extraction with water. Biomed Research International. 2016;2016:5973760. https://doi.org/10.1155/2016/5973760.
13. Hameedi M, Khan SU, Wani SH. Organic biostimulants reduce pest incidence in bell pepper. Journal of Entomology and Zoology Studies. 2022;10(2):199-204.
14. Honnapa P, Kumar S, Reddy A. Humic substances improve phenological events and productivity in chilli. Journal of Applied and Natural Science. 2025;17(2):567-573.
15. Jakhar ML, Singh D, Rathore S. Effect of Panchagavya and Jeevamrut on flowering and yield of okra. Journal of Pharmacognosy and Phytochemistry. 2022;11(5):785-789.
16. Jan I, Khan N, Jan S. Effect of amino acid sprays on growth and yield of chilli. International Journal of Chemical Studies. 2020;8(5):140-144.
17. Jha S, Patel S, Singh P. Vegetable production scenario in India: Current status and future prospects. Indian Journal of Horticulture. 2019;76(4):543-550.
18. Khan A, Ali M, Ahmed S. Role of amino acid formulations on yield and quality of bell pepper. Journal of Plant Nutrition. 2018;41(10):1331-1338.
19. Kiran P, Reddy P, Reddy G. Effect of foliar biostimulants on growth and yield of chilli (Capsicum annuum L.). International Journal of Agricultural Sciences. 2021;13(6):112-116.
20. Kumar V, Singh R, Thakur P. Role of Ascophyllum nodosum extract on chlorophyll and yield in okra. International Journal of Agricultural Sciences. 2023;15(1):55-60.
21. Lee SK, Kader AA. Preharvest and postharvest factors influencing vitamin C content of horticultural crops. Post harvest Biology and Technology. 2000;20(3):207220.
22. Lekshmi V. Organic formulations in reducing disease incidence in chilli. Indian Phytopathology. 2011;64(2):123-128.
23. Naroozlo FK, Azizi M, Kavoosi G. Effect of foliar application of amino acids on photosynthesis and yield of tomato. Journal of Plant Growth Regulation. 2019;38(4):1234-1245.
24. Noushad M, Rani S, Kumar S. Effect of protein hydrolysates on fruiting and yield of chilli. Journal of Pharmacognosy and Phytochemistry. 2024;13(1):456460.
25. Premprakash Singh R, Patel D, Verma R. Influence of Jeevamrut on flowering and yield of tomato. International Journal of Agricultural Sciences. 2021;13(2):330-334.
26. Pruthi JS. Spices and condiments: Chemistry, microbiology and technology. Academic Press; 1976.
27. Ruban V, Kumar M, Singh R. Effect of amino acid sprays on brinjal. Journal of Pharmacognosy and Phytochemistry. 2019;8(3):1043-1046.
28. Sayaf AM, Al-Otaibi A, Ibrahim S. Role of amino acidbased foliar spray in enhancing chlorophyll and photosynthetic efficiency in chilli. Journal of Plant Nutrition. 2024;47(5):815-823.
29. Selvaraj IC, Venkatesh J, Ramakrishnan R. Effect of Panchagavya on growth and yield of crops: A review. Agricultural Reviews. 2007;28(3):199-206.
30. Shazia K, Nisar A, Bhat MA. Amino acid sprays improve growth and productivity of chilli. Journal of Pharmacognosy and Phytochemistry. 2021;10(1):254258.
31. Sugandhika K, Dhanush K, Praveen K. Seaweed extracts enhance disease tolerance in capsicum. Journal of Plant Pathology. 2021;103(4):879-884.
32. Traon D, Amat L, Zotz F, Du Jardin P. A legal framework for plant biostimulants in the EU. Agronomy for Sustainable Development. 2014;34(3):867-871.
33. Vidanapathirana D, Perera P, Jayasena K. Effect of Panchagavya on growth and pest incidence in capsicum. Journal of Tropical Agriculture. 2021;39(2):55-62.