A Study on the Potential Effects of Seaweed Liquid Fertilizer on the Germination and Growth of Asparagus Bean

Abstract

The effects of the use of liquid seaweed fertiliser on Vigna unguiculata subsp. sesquipedalis growth, phytotoxicity, and productivity were evaluated in the present research. Essentially different levels of seaweed fertilizer which had been specifically treated (T0-T5) to asparagus bean and the radical length, the length of hypocotyl, the total length of the seedling, phytotoxicity, the index of growth, the index of vigour, phytomass as well as the productivity had been measured. The findings showed that the moderate level of seaweed extract supply improved the growth properties significantly. T3 possessed the highest radical (4.8 cm), hypocotyl (3.7 cm) and total seedling length (8.5 cm), higher index of vigour (8.5). Greater concentrations (T4) resulted in less efficient growth and this indicates that the response was concentration-dependent. The greatest phytomass and productivity (0.513 g and 0.0366 respectively) were observed in T1. It is an indication that seaweed fertiliser is effective at optimum concentrations to support biomass proliferation. The findings indicate that using liquid seaweed fertiliser is an eco-friendly biostimulant that can assist Vigna unguiculata subsp. sesquipedalis to grow and to produce more productively. Nevertheless, increased concentration of it may be toxic to plants. The results support the idea that agricultural systems should use the compounds of seaweeds that are sustainable to enhance the performance of plants and encourage environmental sustainability.

Introduction

Rapid population growth has increased food scarcity, leading to malnutrition in developing countries such as India. Enhancing vegetable productivity can help address nutritional deficiencies, but conventional chemical fertilizers harm soil quality and biodiversity. Organic fertilizers, particularly seaweed-based fertilizers, offer a sustainable alternative. Caulerpa taxifolia, a marine algae, can be used as a liquid seaweed fertilizer (LSF) to improve seed germination, nutrient uptake, disease resistance, and crop yield.

This study investigated the effect of LSF from C. taxifolia on the growth and productivity of Asparagus bean (Vigna unguiculata subsp. sesquipedalis). Seeds were treated with varying concentrations (1–5%) of seaweed extract, and growth parameters such as radicle and hypocotyl length, germination percentage, growth index, vigor index, phytomass, and productivity were measured.

Results showed that intermediate concentrations (3%) of LSF produced the best overall growth, with the highest seedling length, hypocotyl growth, germination rate (100%), growth index, and vigor index. Very high concentrations (4–5%) caused phytotoxic effects and reduced physiological efficiency. The study confirmed that seaweed extract contains growth-promoting compounds like cytokinins and auxins, enhancing nutrient uptake, enzymatic activity, and photosynthetic capacity, but its effectiveness is highly concentration-dependent.

Conclusion

The current study examined the effect of the fertilizer of liquid seaweed to the growth and productivity of Vigna unguiculatas ssps. sesquipedalis. The concentrations of the seaweed extracts of T0-T5 were put to experiment to test their influence on the lengths of radicles, length of the hypocotyl, seedling length, phytotoxicity, index of vigor, and phytomass. The findings proved that seaweed fertilizer had a great impact on the physiological and morphological characteristics of Vigna unguiculatas subsps. sesquipedalis. The overall growth response of T3 was the best, meaning that moderate levels of liquid seaweed extract have the best balance of nutrients and bioactive compounds to promote plant growth. Seaweed extracts have been found to include natural growth-promoting compounds including auxins, cytokinins, betaine and minerals, which stimulate photosynthesis, enzymatic activity, and cellular metabolism. The significant increase in the growth indices and productivity was at moderate fertilizer concentrations. Nevertheless, when the concentrations were high (T4 and over) the vigor was less and there was even a possibility of phytotoxicity implying that when it is used to the extreme it could cause imbalance in the physiological functions and also could suppress growth. To conclude, liquid seaweed fertilizer are successfully applied as a natural biostimulant to improve the growth and production of Vigna unguiculatas ssps. sesquipedalis. The paper emphasizes on the need to optimize concentration to gain maximum benefits with less stress impacts. These results justify that marine-based biofertilizers are sustainable to be used as alternatives to the chemical inputs to ensure a healthier growth in the marine and agricultural plant systems.

References

[1] Battacharyya, D., Babgohari, M. Z., Rathor, P., & Prithiviraj, B. (2015). Seaweed extracts as biostimulants in horticulture. Scientia Horticulturae, 196, 39–48. https://doi.org/10.1016/j.scienta.2015.09.012 [2] Craigie, J. S. (2011). Seaweed extract stimuli in plant science and agriculture. Journal of Applied Phycology, 23(3), 371–393. https://doi.org/10.1007/s10811-010-9560-4 [3] Khan, W., Rayirath, U. P., Subramanian, S., Jithesh, M. N., Rayorath, P., Hodges, D. M. & Prithiviraj, B. (2009). Seaweed extracts as biostimulants of plant growth and development. Journal of Plant Growth Regulation, 28(4), 386–399. https://doi.org/10.1007/s00344-009-9103-x [4] Ramya, S.S., Nagaraj, S., and Vijayanand, N. 2011. Influence of seaweed liquid extracts on growth, biochemical and yield characteristics of Cyamopsistetragonolaba(L.) Journal of Phytology 3(9): 37-41. [5] Rengasamy, K. R. R., Kulkarni, M. G., & Stirk, W. A. (2015). Accumulation of osmolytes and phenolic compounds in soybean plants subjected to drought stress and treated with seaweed extract. South African Journal of Botany, 100, 117–123. https://doi.org/10.1016/j.sajb.2015.05.028 [6] Sharma, H. S. S., Fleming, C., Selby, C., Rao, J. R., & Martin, T. (2014). Plant biostimulants: A review on the processing of macroalgae and use of extracts for crop management to reduce abiotic and biotic stresses. Journal of Applied Phycology, 26(1), 465–490. https://doi.org/10.1007/s10811-013-0101-9 [7] Thirumaran, G., Anantharaman, P., and Kannan, L. 2007. Effect of seaweed extracts used as a liquid fertilizer in the radish (Raphanus sativus). Journal of Ecobiology 20(1): 49-52. [8] Verkleij, F. N. (1992). Seaweed extracts in agriculture and horticulture: A review. Biological Agriculture & Horticulture, 8(4), 309–324. https://doi.org/10.1080/01448765.1992.9754608 [9] Zodape, S. T., Kawarkhe, V. J., Patolia, J. S., & Warade, A. D. (2011). Effect of liquid seaweed fertilizer on yield and quality of okra (Abelmoschus esculentus L.). Journal of Scientific & Industrial Research, 70(3), 215–219.

Copyright

Copyright © 2025 Abhilash ES, Shilpha K, Vaishnavi , Akshara , Jishnu , Abinand , Yamuna VG, Binumol M. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.