Influence of foliar applied micronutrients on seed quality characteristics of sesame (Sesamum indicum L.)

Introduction

Sesame (Sesamum indicum L.) is known as the "Queen of Oilseeds" and is one of the oldest oilseed crops cultivated across tropical and subtropical regions. It is valued for its high oil content (45-50%), high-quality protein and natural antioxidants-sesamin, sesamol and sesamolin-which contribute to the stability and nutritional value of sesame oil (Namiki, 2007; Ashri, 2007) [2,1] . Despite its significance, sesame productivity in India (400-450 kg ha -1 ) remains considerably lower than its potential, partly due to inadequate micronutrient management (Anonymous, 2023) [3] . Seed quality is a critical determinant of crop st and establishment and ultimately of productivity. High-quality seeds are characterised by a high germination percentage, greater seedling vigour and high oil content-parameters that are significantly influenced by the nutritional status of the mother plant during seed development. Micronutrients such as zinc (Zn), boron (B), iron (Fe) and manganese (Mn) play pivotal roles in reproductive physiology, biochemical reserve deposition and membrane integrity of developing seeds. Zinc is essential for auxin synthesis, enzyme activation and protein metabolism; boron facilitates carbohydrate translocation and pollen viability; iron is required for chlorophyll synthesis and respiration; and manganese participates in photosynthetic electron transport and fatty acid synthesis (Marschner, 2012; Havlin et al., 2014) [5,4] . Deficiency of any of these elements during seed development compromises the physiological quality of seeds. Foliar application of micronutrients at critical growth stages has been shown to effectively improve seed quality. Parsaei et al. (2017) [6] reported that foliar application of zinc and boron significantly improved germination percentage and vigour indices in sesame. Dhaliwal et al. (2021) [7] found that foliar application of boron at 30 mg/L enhanced antioxidant activity and oil content of sesame seeds. Elayaraja et al. (2020) [8] recorded higher germination percentage and 1000-seed weight in sesame with zinc and manganese treatments. However, comprehensive information on the response of multiple seed quality parameters to the foliar application of micronutrients, particularly their combined application, is limited. The present study was therefore undertaken to evaluate the effect of foliar application of boron, zinc, ferrous and manganese-individually and in combination-on germination percentage, Seedling Vigour Index-I, Seedling Vigour Index-II and oil content of sesame seeds.

Materials and Methods

Experimental site and design: The experiment was conducted at the Quality Seed Production Unit, Khanapur-A, VNMKV, Parbhani, Maharashtra, during the summer season of 2025-26 on uniform black cotton soil. The experiment was laid out in a RBD with 9 treatments and 3 replications using the sesame variety "TLT-10". Foliar sprays were applied at 30 and 60 DAS. The plot size was 1.2 × 3.0 m (3.6 m 2

), with row-to-row spacing of 30 cm and plant-to-plant spacing of 15 cm. The treatments were: T 1 -Control; T 2 -Boron (Borax) @ 0.3 g/L; T 3 -Zinc (ZnSO 4 ) @ 0.3 g/L; T 4 -Ferrous (FeSO 4 ) @ 0.4 g/L; T 5 -Manganese (MnSO 4 ) @ 0.2 g/L; T 6 -Boron + Ferrous (0.3 + 0.4 g/L); T 7 -Zinc + Ferrous (0.3 + 0.4 g/L); T 8 -Ferrous + Manganese (0.4 + 0.2 g/L); and T 9 -T 2 + T 3 + T 4 + T 5 .

Seed quality parameters assessed

(i) Germination percentage: Germination was assessed using the topof-paper (TP) method as described by ISTA (1985) [9] . Four hundred pure seeds, comprising four replicates of 100 seeds each, were placed on moistened filter paper in Petri dishes and kept at 25 ± 1 °C for six days. Normal seedlings were counted on the final count day and germination percentage was calculated. (ii) Seedling Vigour Index-I (SVI-I): SVI-I was calculated as Germination (%) × Seedling length (cm), following Abdul-Baki and anderson (1973) [10] . (iii) Seedling Vigour Index-II (SVI-II): SVI-II was calculated as Germination (%) × Seedling dry weight (g). (iv) Oil content (%): Oil content was determined using approximately 25 g of clean seeds from each plot by the Nuclear Magnetic Resonance (NMR) method.

Results and Discussion

Analysis of variance revealed highly significant differences among the treatments for all four seed quality parameters studied, namely, germination percentage, Seedling Vigour Index-I, Seedling Vigour Index-II and oil content, indicating the differential influence of foliar micronutrient application on seed physiological quality in sesame. The results are presented and discussed below.

Germination percentage

Germination percentage differed significantly among the treatments. The highest germination percentage was recorded in T 9 (89.00%), followed by T 7 (88.00%) and T 8 (87.00%), while the minimum was recorded in T 1 (82.33%), followed by T 2 and T 5 (84.00% each). The grand mean for germination percentage was 85.78%, with treatment means ranging from 82.33 to 89.00%. The superior germination under T 9 is attributable to the combined role of all four micronutrients in enhancing seed filling, metabolic reserve deposition and membrane integrity during seed development on the mother plant. Zinc promotes protein synthesis and enzymatic activity during seed maturation; boron facilitates carbohydrate translocation and ensures adequate starch deposition; iron supports chlorophyll synthesis, thereby improving the photosynthetic capacity of the mother plant; and manganese participates in superoxide dismutase activity, thereby reducing oxidative damage to developing seeds. Together, these functions result in physiologically mature seeds with higher germinability. These findings are in conformity with Parsaei et al. (2017) [6] , who reported that foliar application of zinc and boron, individually or in combination, significantly improved seed germination percentage in sesame under accelerated ageing conditions. Elayaraja et al. (2020) [8] also recorded higher germination percentage in sesame with combined zinc and manganese foliar treatments. The superior germination observed under combined micronutrient treatments reflects the synergistic benefits of balanced micronutrient nutrition on seed physiological quality.

Seedling vigour index-I

Significant differences were recorded among the treatments for Seedling Vigour Index-I (SVI-I). The maximum SVI-I was recorded in T 9 (1775.3), followed by T 3 (1687.2) and T 7 (1574.3), while the minimum was recorded in T 1 (1183.0), followed by T 6 (1396.1) and T 5 (1491.2). The gr and mean for SVI-I was 1520.0. SVI-I, calculated as the product of germination percentage and seedling length, reflects early growth vigour and seedling establishment potential. The higher SVI-I under T 9 is attributed to the combined effect of all four micronutrients in improving the biochemical reserves and hormonal status of seeds, resulting in rapid and uniform germination and vigorous seedling elongation. Zinc-mediated auxin synthesis is particularly important for seedling elongation, which may explain why T 3 (Zn alone) ranked second for SVI-I. These findings are consistent with Parsaei et al. (2017) [6] , who documented that the combined foliar application of Zn and B produced sesame seeds with significantly higher vigour indices and improved germination. Sonakamble et al. (2015) [11] also reported a significantly higher vigour index with ZnSO 4 application through soil and foliar spray in soybean.

Seedling vigour index-II

Treatment T 9 recorded the highest Seedling Vigour Index-II (SVI-II) value of 304.39, followed by T 7 (289.51) and T 8 (282.75), while T 1 registered the lowest SVI-II value of 241.24, followed by T 5 (252.01) and T 2 (254.52). The gr and mean for SVI-II was 269.92. SVI-II, calculated as the product of germination percentage and seedling dry weight, is considered a more sensitive indicator of seed vigour, as it quantifies the dry matter accumulation capacity of seedlings during early establishment. The higher SVI-II under T 9 reflects the greater accumulation of metabolic reserves-proteins, lipids and carbohydrates-in seeds during development under balanced micronutrient nutrition, enabling more vigorous seedling growth and greater dry matter accumulation. The strong performance of T 7 for SVI-II, ranking second, indicates that the zinc-iron combination is particularly effective in promoting seedling dry weight accumulation, possibly through the role of zinc in protein synthesis and iron in chlorophyll-dependent photosynthate production and supply to developing seeds. These results are supported by Parsaei et al. (2017) [6] , who found that the combined foliar application of Zn and B produced sesame seeds with superior physiological quality and enhanced antioxidant enzyme activities, thereby improving Seedling Vigour Index-II. Sreepriya et al. (2019) [12] similarly documented that manganese sulphate-primed sesame seeds produced significantly higher seedling vigour and field emergence compared with unprimed seeds.

Oil content differed significantly among the treatments. The maximum oil content was recorded in T 9 (46.99%), followed by T 5 (46.90%) and T 4 (46.50%), while the minimum was recorded in T 1 (45.00%), followed by T 7 (45.20%) and T 6 (45.30%). The gr and mean for oil content was 45.94%, with treatment means ranging from 45.00 to 46.99%. An important observation from the oil content data is the combination-specific response of oil biosynthesis. While T 9 recorded the highest oil content overall, the individual treatments T 5 and T 4 ranked second and third, respectively, with notably higher oil content than the dual combinations T 7 and T 6 . This pattern suggests that manganese and iron, when applied individually, may channel available photosynthates preferentially towards lipid biosynthesis, whereas in the zinciron combination (T 7 ), the strong vegetative growth and yield expression may redirect assimilates towards seed structural components rather than oil accumulation. The role of manganese in fatty acid biosynthesis-through its function as a cofactor of acetyl-CoA carboxylase and other lipid-metabolism enzymes-may explain the relatively higher oil content under T 5 . Similarly, the involvement of iron in respiration and energy supply for lipid biosynthesis may account for the higher oil content under T 4 . These findings are consistent with Habimana et al. (2016) [13] , who reported higher oil content and oil yield in sesame with manganese sulphate application and with Dhaliwal et al. (2021) [7] , Khuong et al.

(2022) [14] and Dey et al. (2023) [15] , who recorded significant increases in oil content following foliar boron application in sesame. Saudy et al. (2022) [16] similarly reported that a foliar nano-mixture of iron, zinc and manganese enhanced the oil content of sesame seeds. The observation that T 7 produced comparatively lower oil content despite its high seed yield is consistent with the findings of Rekani (2019) [17] , who reported that the response of sesame to foliar appli-cation of iron and manganese in terms of oil synthesis is dose-and combination-specific. Maheshwari et al. (2023) [18] further reported that combined foliar application of Zn + B + Fe resulted in maximum 1000-seed weight and oil content in sesame, supporting the beneficial role of combined micronutrient nutrition in improving seed biochemical quality.

Conclusion

The results of the present investigation clearly demonstrate that foliar application of micronutrients significantly improved all the seed quality parameters of sesame. The combined treatment T 9 , applied at 30 and 60 DAS, was the most effective treatment, recording the highest germination percentage (89.00%), Seedling Vigour Index-I (1775.3), Seedling Vigour Index-II (304.39) and oil content (46.99%) compared with the control. The combined application of all four micronutrients improved photosynthetic efficiency, biochemical reserve deposition, membrane integrity and enzymatic antioxidant activity, collectively contributing to superior seed physiological quality. An important finding was the combination-specific response of oil biosynthesis, with individually applied manganese (T 5 ) and ferrous sulphate (T 4 ) being relatively more effective in enhancing oil content than certain dual combinations. On the basis of the present findings, combined foliar application of boron, zinc, ferrous sulphate and manganese (T 9 ) is recommended as an effective nutrient management strategy for improving seed quality parameters and producing high-quality sesame seed lots under the agro-climatic conditions of Marathwada, particularly in seed production programmes.

References

1. Ashri A. Sesame (Sesamum indicum L.). In: Singh RJ, editor. Genetic resources, chromosome engineering, and crop improvement: Oilseed crops. Boca Raton, FL, USA: CRC Press, Taylor and Francis Group; 2007. p. 231-289.
2. Namiki M. Nutraceutical functions of sesame: A review. Critical Reviews in Food Science and Nutrition. 2007;47(7):651-673.
3. Anonymous. Agricultural statistics at a glance. Government of India; 2023.
4. Havlin JL, Tisdale SL, Nelson WL, Beaton JD. Soil fertility and fertilizers: An introduction to nutrient management. 8th ed. Pearson; 2014.
5. Marschner P, editor. Marschner's mineral nutrition of higher plants. 3rd ed. Academic Press; 2012.
6. Dhaliwal SS, Sharma V, Shukla AK, Verma V, Behera SK, Sandhu PS, Kaur K, Gaber A, Althobaiti YS, Abdelhadi AA, Hossain A. Assessment of agroeconomic indicators of Sesamum indicum L. as influenced by application of boron at different levels and plant growth stages. Molecules. 2021;26(21):6699.
7. Elayaraja D, Singaravel R. Effect of foliar application of zinc and manganese on yield and quality of sesame (Sesamum indicum L.). Journal of Pharmacognosy and Phytochemistry. 2020;9(4):15651569.
8. Abdul-Baki AA, Anderson JD. Vigor determination in soybean seed by multiple criteria. Crop Science. 1973;13(6):630-633.
9. Sonakamble AM et al. Highest vigour index and seed recovery obtained from ZnSO 4 soil application and foliar spray. Karnataka Journal of Agricultural Sciences. 2015.
10. Sreepriya S, Girija T. Seed invigoration-a technique for improving vigour and productivity of sesame (Sesamum indicum L.) variety Thilak. Journal of Tropical Agriculture. 2019;57(1):10-16.
11. Habimana F, Stalin P, Muthumanickam D. Effect of manganese nutrition on growth, yield, manganese uptake and quality of sesame. Advances in Applied Research. 2016;8(1):14-18.
12. Khuong N, Thuc L, Tran N, Huu T, Sakagami J. Foliar application of boron positively affects the growth, yield, and oil content of sesame (Sesamum indicum L.). Open Agriculture. 2022;7(1):30-38.
13. Dey A, Begum M, Kabiraj MS, Rashid MH, Paul SK. Influence of foliar application of boron on the growth, yield and quality of sesame (cv. BARI Til-4). Turkish Journal of Agriculture -Food Science and Technology. 2023;11(12):2356-2364.
14. International Journal of Advanced Biochemistry Research https://www.biochemjournal.com 26174707, 2026, 10(9), Downloaded from https://www.doi.org/10.33545/26174693.2026.v10.i9Sag.10234 by International Journal of Advanced Biochemistry Research on [30/09/2026]. See the Terms and Conditions (https://www.biochemjournal.com) for rules of use; OA articles are governed by the applicable Creative Commons License
15. Saudy HS, Abd El-Samad GA, El-Temsah ME, El-Gabry YAE. Effect of iron, zinc and manganese nano-form mixture on micronutrient recovery efficiency and seed yield response index of sesame genotypes. Journal of Soil Science and Plant Nutrition. 2022;22:732-742.
16. Rekani SI. Effect of high concentration of Fe and Mn as foliar application on growth and yield of sesame grown in calcareous soil. International Journal of Science and Research. 2019;8(11):943946.
17. Maheshwari B, Mehera B, Kumar P, Mondal S. Effect of foliar application of micronutrients on growth and yield of sesame (Sesamum indicum L.). International Journal of Plant and Soil Science. 2023;35(12):69-73.
18. Anonymous. FAO statistical database for global sesame production and area. Food and Agriculture Organization, Rome; 2023.
19. 421-426. How to cite this article: Sakhare C, Misal A, Rathod A, Pedhekar H, Gaikwad A, Gulwade S, et al. Influence of foliar applied micronutrients on seed quality characteristics of sesame (Sesamum indicum L.). International Journal of Advanced Biochemistry Research. 2026;SP-10(9):2659-2662. doi: https://w ww.doi.org/10.33545/26174693.2026.v10.i9Sag.10234