Efficacy of Ethanol Extract of Leftover Chili (Capsicum annuum var. frutescens L.) on Weed Control, Growth and Yield of Thai Eggplants (Solanum xanthocarpum Schrad. & Wendl.)
DOI:
https://doi.org/10.65411/rst.2026.265348Keywords:
Ethanol extract, Weed control, Leftover chili, Thai eggplant, CapsaicinoidsAbstract
Weeds pose major problems for farmers as they compete for essential factors for plant growth, thereby affecting crop yields. Currently, natural methods are increasingly popular for weed control. In the study area where vegetables like chili and eggplant are grown for consumption and sale, a significant weed problem in the eggplant plots led to low quality and insufficient yields. This prompted the researcher to investigate using leftover chili extract to control weeds. This study aimed to evaluate the efficacy of ethanol extracts of leftover chili in controlling weeds. The extract was prepared using a 70% ethanol solution, filtered to separate pulp, then diluted with water to a 30% alcohol concentration, and poured into a spray bottle. Three treatment groups were tested: Control Group 1 (pulling weeds by hand), Control Group 2 (spraying with 30% ethanol), and Experimental Group (spraying with chili extracts). Treatments were applied around the base of eggplant plants every 10 days for 90 days. The growth of both Thai eggplant and weeds was measured by assessing height above the soil surface, counting weed growth, and counting eggplant fruit after spraying. Statistical analyses included mean and analysis of variance. The results showed that the chili extract significantly reduced weed germination and growth (dry weight), performing comparably to manual weeding. Notably, eggplant yields in the chili extract group were the highest, significantly outperforming the ethanol control and matching manual weeding. This indicates the extract's potential for effective, chemical-free weed control that supports crop growth.
References
IFOAM Organics International. 2024. The Principle of Health. Available Source: https://www. ifoam.bio/why-organic/principles-
organic-agriculture/principle-health, June 23, 2025.
Jirapong, L. 1999. Preparation and Use of Herbal Plant for Pests Control. Institute for the Promotion of Organic Agriculture and Farmer Schools, Department of Agricultural Extension, Bangkok. (in Thai)
Kaewnoi, A., Manok, S., Duanyai, S. and Hongprom, Y. 2018. Development of Capsaicin Extract from Rangsima Chili for Use in Making Chili Gel Product. Chalermkanjana Academic Journal 5(1): 48-54. (in Thai)
Kongsaengdao, S., Sukprasit, A. and Kongjiang, K. 2010. Weed Control in Eggplant. Experimental Report. Weed Research Group, Plant Protection Research and Development Office and Horticultural Research Center, Kanchanaburi. (in Thai)
Mensin, S., Boonkhan, W., Burutpakdi, W. and Promsorn, W. 2021. Research Report on Biological and Substitute for Agricultural Chemicals for Cultivation of Environmentally Friendly Plants of High Areas. High Area Research and Development Institute (Public Organization). (in Thai)
Nicholson, J. 2022. The Effect of Alcohol on Plants. Available Source: https://sciencing.com/ effect-alcohol-plants-8006187.html, August 30, 2024.
Pinsupa, J. and Nakhon Si, K. 2010. Research Report on Research and Development of Substances from the Wild Spikenard for Weeds Prevention and Elimination. Department of Agriculture (DOA). (in Thai)
Poonpiboonpipat, T. and Wachoo, M. 2020. The Efficiency of Certain Types of Weeding Substances on the Control of Nut Grass and Toxicity to Corn. Journal of Agriculture Naresuan 17(1): 48-57. (in Thai)
Preedapatarapong, N. 1994. Production of Oleoresin and Oil Plant from Chili. Graduate School, Kasetsart University, Bangkok. (in Thai)
Radosevich, S., Holt, J. and Ghersa, C. 2007. Ecology of Weeds and Invasive Plants: Relationship to Agriculture and Natural Resource Management. Wiley, New York.
Saeung, P. and Punya, N. 2022. Effects of Ocimum canum SIMS. Extract on Seed Germination and Growth of Plants. Journal of Research and Development, Valaya Alongkorn Rajabhat University under the Royal Patronage (Science and Technology) 17(2): 61-71. (in Thai)
Salzer, U.J. 1977. The analysis of Essential Oils and Extracts (Oleoresin) from Seasonings – a Critical Review. CRC Critical Review in Food Science and Nutrition 9(4): 345-373.
Sardana, V., Mahajan, G., Jabran, K. and Chauhan, B.S. 2017. Role of Competition in Managing Weeds. Crop Protection 95(Special Issue): 1-7.
Sayan, P. and Suwanprateep, S. 2015. Research Report on Analysis of Capsaicin Content in Chili by Fourier Transform Infrared Spectroscopy. Rajamangala University of Technology Suvarnabhumi. (in Thai)
Sila-on, P. 2021. Wisdom of the land | Bio-extract for grass knock out. Golden Jubilee Museum of Agriculture. Available source: http://www.youtube.com/watch?v=asGtUQ-sldc, October 28, 2021. (in Thai)
Soiklom, S., Prommais, P. and Klinchan, S. 2013. Efficiency of Pepper Extracts with Anti-bacterial Activity, pp. 286-291. In Proceedings of the 51st Kasetsart University Annual Conference: Plant Science. Kasetsart University, Bangkok. (in Thai)
Sukkhang, S., Promdaeng, S., Saejiew, A. and Suwanwong, S. 2019. Crude Extracts from Tamarind Shells (Tamarindus indica L.), Lemon Grass (Cymbopogon citratus Stapf.) and Citronella Grass (Cymbopogon nardus Rendle.) Inhibit Germination and Growth of Minnieroot (Ruellia tuberosa Linn.). Agricultural Science and Management 2(3): 29-36. (in Thai)
Tosena, K., Thumsaen, B., Songsri, P. and Konkhamdee, S. 2018. Growth Inhibitors of Some Weeds and Crops by Using Wood Vinegar in Combination with Pre-Emergence Herbicides. Kaen Kaset Journal 46(5): 901-910. (in Thai)
Urit, T. 2020. Research Report on Adding Value to Organic Pepper Leaves from Agricultural Waste into Commercial Prebiotic Herbal Fermentation Products. Naresuan University. (in Thai)
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2025 Recent Science and Technology
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
The content and information in the article published in Journal of Rajamangala University of Technology Srivijaya It is the opinion and responsibility of the author of the article. The editorial journals do not need to agree. Or share any responsibility.
