Abstract
Early blight, caused by Alternaria solani, is an important fungal disease that serves as a serious limitation to tomato production, mainly in high-humidity and warm areas of Nepal. The present study was conducted to explore the in vitro efficacy of Trichoderma isolates and botanical extracts against A. solani. The pathogen was isolated from infected tomato plants and subjected to dual culture and poisoned food assays in a completely randomized design with five replications. Three species of Trichoderma (T. asperellum, T. harzianum, and T. viride) and four selected plant extracts (Azadirachta indica, Ocimum basilicum, Cymbopogon citratus, and Psidium guajava leaves) were tested for their effectiveness to inhibit A. solani mycelial growth over a period of 10 days. All the treatments significantly inhibited the mycelia growth in comparison to the control. T. asperellum showed the highest inhibitory activity (0.21), followed by T. harzianum and T. viride, thus showing their good antagonistic potential against A. solani. Similarly, among botanical extracts, Azadirachta indica leaf extract was most effective in inhibiting the mycelia growth (83.78), followed by O. basilicum and C. citratus extracts, with P. guajava leaf extract being comparatively less effective. The results indicate that T. asperellum and A. indica leaf extract had the highest mycelial growth inhibition capacity and proved to be effective in in vitro conditions. Therefore, these options must be evaluated further in field conditions against early blight of tomato, which can be a promising eco-friendly approach alternative to synthetic chemical fungicides.
Keywords
References
- Adhikari, P. (2023). Trichoderma: its Ecophysiology, Mechanism of Biocontrol and Application Methods. Journal of Agriculture and Environment, 263–276. https://doi.org/10.3126/aej.v24i01.58203 [Google Scholar]
- Agrios, G. N. (2005). Plant Pathology, 5th Edition. Academic Press, San Diego. [Google Scholar]
- Ajiboye, M. D., & Sobowale, A. A. (2022). Efficacy of native Trichoderma asperellum in managing Alternaria solani causing early blight of Solanum lycopersicum Mill. Archives of Phytopathology and Plant Protection, 55(11), 1358–1378. https://doi.org/10.1080/03235408.2022.2097001 [Google Scholar]
- Alam, S., Nisa, S., & Daud, S. (2022).Mycotoxins in environment and its health implications. In Hazardous environmental micro-pollutants, health impacts and allied treatment technologies (pp. 289-318). Cham: Springer International Publishing.https://doi.org/10.1007/978-3-030-96523-5_12 [Google Scholar]
- Amsaraj, C., Mishra, J., & Prasad, R. (2020). Effect of different solvents on plant extracts for their antifungal activity against Alternaria solani, the causual agent of Early blight of Tomato under In Vitro. Journal of Pharmacognosy and Phytochemistry, 9(3), 588–593. [Google Scholar]
- Bais, R. K., Ratan, V., Kumar, S., & Tiwari, A. (2019). Comparative analysis of various strategies for management of early blight of tomato incited by Alternaria solani (Ellis and Martin) Jones and Grout. The Pharma Innovation Journal, 8(12), 15-20. [Google Scholar]
- Bhanage, S., Patil, N. B., & Singh, S. (2019). Effect of selected botanicals against early blight (Alternaria solani) disease of tomato (Solanum lycopersicum Mill.). Plant Archives, 19, 2839–2842. [Google Scholar]
- Bhandari, S., Pandey, K. R., Joshi, Y. R., & Lamichhane, S. K. (2021). An overview of multifaceted role of Trichoderma spp. for sustainable agriculture. Archives of Agriculture and Environmental Science, 6(1), 72-79.https://doi.org/10.26832/24566632.2021.0601010 [Google Scholar]
- Booth, C. (1971). The Genus Fusarium. Commonwealth Mycological Institute, Kew, Surrey, UK. [Google Scholar]
- Casu, A., CamardoLeggieri, M., Toscano, P., & Battilani, P. (2024).Changing climate, shifting mycotoxins: A comprehensive review of climate change impact on mycotoxin contamination. Comprehensive Reviews in Food Science and Food Safety, 23(2). https://doi.org/10.1111/1541-4337.13323 [Google Scholar]
- Chaudhary, A. K., Yadav, J., Gupta, A. K., & Gupta, K. (2021).Integrated disease management of early blight (Alternaria Solani) of potato. Tropical Agrobiodiversity, 2(2), 77-81. http://doi.org/10.26480/trab.02.2021.77.81 [Google Scholar]
- Dennis, C., & Webster, J. (1971). Antagonistic properties of species-groups of Trichoderma: I. Production of non-volatile antibiotics. Transactions of the British Mycological Society, 57(1), 25-IN3. https://doi.org/10.1016/S0007-1536(71)80077-3 [Google Scholar]
- Dhal, A., Beura, S., Dash, S., Tripathy, L., Swain, S., & Sethi, D. (2017). Eco-Friendly and Integrated Approaches for Management of Early Blight Disease in Tomato. International Journal of Current Microbiology and Applied Sciences, 6(10), 3052–3057. https://doi.org/10.20546/ijcmas.2017.610.359 [Google Scholar]
- Dhaval, P., Shete, P. P., Faraaz, M., & Dholu, D. (2021).Early blight (Alternaria solani) etiology, morphology, epidemiology and management of tomato. Pharma Innovation, 10(5), 1423-1428. [Google Scholar]
- Dutta, P., Mahanta, M., Singh, S. B., Thakuria, D., Deb, L., Kumari, A., & Pandey, A. K. (2023). Molecular interaction between plants and Trichoderma species against soil-borne plant pathogens. Frontiers in plant science, 14, 1145715. http://doi.org/10.3389/fpls.2023.1145715 [Google Scholar]
- Gomez, K. A., & Gomez, A. A. (1984). Statistical procedures for agricultural research .John Wiley & Sons. [Google Scholar]
- Gurjar, M. S., Ali, S., Akhtar, M., & Singh, K. S. (2012). Efficacy of plant extracts in plant disease management. [Google Scholar]
- Hashem, A. H., Abdelaziz, A. M., & Attia, M. S. (2023). Trichoderma a promising biofungicide.In Biofungicides: Eco-Safety and Future Trends (pp. 166-189). CRC Press. [Google Scholar]
- Jaiswal, D. K., Gawande, S. J., Soumia, P. S., Krishna, R., Vaishnav, A., & Ade, A. B. (2022). Biocontrol strategies: an eco-smart tool for integrated pest and diseases management. BMC Microbiology, 22(1), 324. https://doi.org/10.1186/s12866-022-02744-2 [Google Scholar]
- Jan, A., Ali, T., Chirag, S., Ahmed, S., Ali, M., Wali, S., & Ullah, K. (2025). Eco-friendly management of insect pests and plant diseases using botanical extracts. Global Research Journal of Natural Science and Technology. https://doi.org/10.53762/grjnst.03.03.19 [Google Scholar]
- Jindo, K., Evenhuis, A., Kempenaar, C., Pombo Sudré, C., Zhan, X., GoitomTeklu, M., & Kessel, G. (2021).Holistic pest management against early blight disease towards sustainable agriculture. Pest Management Science, 77(9), 3871-3880. https://doi.org/10.1002/ps.6320 [Google Scholar]
- Kaushik, E., Sridevi, R., & Rana, M. K. (2025).Role of Botanicals and Biocontrol Agents in Organic Farming. In Organic Production of Vegetable Crops (pp. 419-441). Apple Academic Press. [Google Scholar]
- Kos, J., Anić, M., Radić, B., Zadravec, M., JanićHajnal, E., &P leadin, J. (2023). Climate change—A global threat resulting in increasing mycotoxin occurrence. Foods, 12(14), 2704. https://doi.org/10.3390/foods12142704 [Google Scholar]
- Manzar, N., Kashyap, A. S., Goutam, R. S., Rajawat, M. V. S., Sharma, P. K., Sharma, S. K., & Singh, H. V. (2022). Trichoderma: advent of versatile biocontrol agent, its secrets and insights into mechanism of biocontrol potential. Sustainability, 14(19), 12786. https://doi.org/10.3390/su141912786 [Google Scholar]
- Maurya, S., Regar, R., Kumar, S., &Dubey, S. (2022). Management tactics for early blight of tomato caused by Alternaria solani: A review. J. Plant Biol. Crop Res, 5, 1062. [Google Scholar]
- Naz, R., Mehmood, S., &Haider, A. (2025). Laboratory and field evaluation of tomato early blight (Alternaria solani). Journal of Environmental Sciences and Sustainability, 2(3), 60-67. [Google Scholar]
- Ngegba, P. M., Cui, G., Khalid, M. Z., &Zhong, G. (2022). Use of botanical pesticides in agriculture as an alternative to synthetic pesticides. Agriculture, 12(5), 600. https://doi.org/10.3390/agriculture12050600 [Google Scholar]
- Pun, L. B., Chhetri, K., Pandey, A., & Paudel, R. (2020). In vitro Evaluation of Botanical Extracts, Chemical Fungicides and Trichoderma harzianum against Alternaria brassicicola Causing Leaf Spot of Cabbage. Nepalese Horticulture, 14, 68-76. https://doi.org/10.3126/nh.v14i1.30612 [Google Scholar]
- SC, N., Tk, N., Tt, N., & Pb, K. (2020). In vitro efficacy of plant extract ( botanicals ) against Alternaria solani ( early blight of tomato ). Journal of Pharmacognosy and Phytochemistry, 9(5), 614–617. [Google Scholar]
- Sharma, V., Kaur, A., & Kumar, A. (2025). Early blight disease management of potato. Potato Research, 68(2), 1869-1892. https://doi.org/10.1007/s11540-024-09816-y [Google Scholar]
- Shoaib, A., & Awan, Z. A. (2021). Mineral fertilizers improve defense related responses and reduce early blight disease in tomato (Solanum lycopersicum L.). Journal of Plant Pathology, 103(1), 217-229. https://doi.org/10.1007/s42161-020-00713-0 [Google Scholar]
- Sigdel, S., Ranabhat, S., Bhandari, S., Magar, P. B., Shrestha, J., & Subedi, S. (2022). In vitro evaluation of different fungicides against Rhizoctonia solani and Alternaria citri infecting citrus. Journal of Agriculture and Natural Resources, 5(1), 138-149. https://doi.org/10.3126/janr.v5i1.50703 [Google Scholar]
- Singh, R. (2022). Studies on Epidemiology and management of early blight of tomato caused by Alternaria solani (Doctoral dissertation, RajmataVijayarajeScindia Krishi VishwaVidyalaya). [Google Scholar]
- Singh, S., Dureja, P., Tanwar, R. S., & Singh, A. (2005).Production and antifungal activity of secondary metabolites of Trichoderma virens. Pesticide Research Journal, 17(2), 26-29. [Google Scholar]
- Solankey, S. S., Ray, P. K., Kumari, M., Singh, H. K., Shamim, M., Verma, D. K., & Jha, V. B. (2021).Tomato diseases, their impact, and management. In Biotic stress management in tomato (pp. 1-23). Apple Academic Press. [Google Scholar]
- Stracquadanio, C., Quiles, J. M., Meca, G., & Cacciola, S. O. (2020).Antifungal activity of bioactive metabolites produced by Trichoderma asperellum and Trichoderma atroviride in liquid medium. Journal of Fungi, 6(4), 263. [Google Scholar]
- Vincent, J. M. (1947). Distortion of fungal hyphae in the presence of certain inhibitors. Nature, 159(4051), 850-850. [Google Scholar]
- Wagle, S. P. (2023). Prospects and Barriers of Commercial Tomato Farming in Hilly Areas of Eastern Nepal. Rupantaran: A Multidisciplinary Journal, 7(1), 90-100. [Google Scholar]
- Yogi, B., Chhetri, D. R., Marasini, K. P., &Rauniyar, K. (2024). Production Practices, Marketing, And Economics Of Tomato In Panchapuri Municipality Of Surkhet District. Food & Agribusiness Management (FABM), 5(2), 124-130 [Google Scholar]

