Effect of Dormancy-Breaking Techniques on Seedling Emergence and Growth of Cashew (Anacardium occidentale L.) in the Nursery
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Abstract
Cashew (Anacardium occidentale L.) seed propagation is frequently hampered by irregular and delayed seedling emergence, particularly in larger-seeded biotypes, yet systematic evaluation of dormancy-breaking techniques across nut size categories remains limited in the literature. The study evaluated pre-sowing dormancy-breaking treatments on nursery performance of three cashew nut biotypes. A 3 × 3 factorial experiment arranged in a Completely Randomized Design (CRD) was conducted at the Cocoa Research Institute of Nigeria (CRIN), Ibadan. Three dormancy-breaking treatments include control, 3% H₂O₂ immersion (16 hours) and mechanical scarification, were applied to three cashew biotypes (medium, large and extra-large). Emergence, morphological, biomass and root parameters were recorded and analyzed using ANOVA with Tukey's HSD test (p ≤ 0.05). Mechanical scarification consistently reduced days to emergence (13 days in extra-large seeds versus 20 days in the untreated control), achieved the highest cumulative emergence percentages across all biotypes (100% in medium; 77.50% in extra-large) and produced superior seedling height, leaf area, shoot biomass and root development indices. H₂O₂ treatment accelerated early emergence in large and extra-large seeds but exhibited phytotoxic effects in medium biotypes, suppressing final emergence percentage (51.00%) and seedling vigour. Extra-large seeds recorded the most severe physical dormancy under untreated conditions (49.00% final emergence at 28 days after sowing). Mechanical scarification is the most reliable and broadly applicable dormancy-breaking technique for cashew nursery production across the three biotypes, improving both emergence uniformity and seedling quality for field transplanting. Mechanical scarification is recommended for cashew nursery production across the three nut size biotypes.
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Copyright (c) 2026 Olufemi Aremu-Dele, Edugie Christerbeth Ogbeide, Tajudeen Kolade AbdulKabir, Adeshola Esther Ayodele, El-Rohi Kofoworola Oni-Michael, Olamide Damilola Adekunle (Author)

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Adeigbe, O. O., Olasupo, F. O., Adewale, B. D., & Muyiwa, A. A. (2015). A review on cashew research and production in Nigeria in the last four decades. Scientific Research and Essays, 10(5), 196–209. https://doi.org/10.5897/SRE2014.5953 DOI: https://doi.org/10.5897/SRE2014.5953
Adeyemi, E. A., Tijani-Eniola, H., Ogunlade, M. O., & Omitade, O. O. (2016). Cashew (Anacardium occidentale) biotypes, nut forms and nut soaking effects on seedling emergence and growth. Acta Horticulturae, 1225, 443–450. https://doi.org/10.17660/ActaHortic.2018.1225.63 DOI: https://doi.org/10.17660/ActaHortic.2018.1225.63
Attri, V., Brar, P. S., & Saralch, H. S. (2025). Effect of seed size and presowing treatments on germination, early seedling growth and seedling vigour of Senegalia catechu (L.f.) P.J.H. Hurter and Mabb. in nursery condition. Bhartiya Krishi Anusandhan Patrika, 40(2), 158–165. https://doi.org/10.18805/BKAP841 DOI: https://doi.org/10.18805/BKAP841
Baskin, C. C., & Baskin, J. M. (2000). Seeds: Ecology, biogeography, and evolution of dormancy and germination. Academic Press.
Basu, S., & Groot, S. P. C. (2023). Seed vigour and invigoration. In M. Dadlani & D. K. Yadava (Eds.), Seed science and technology: Biology, production, quality (pp. 67–89). Springer. https://doi.org/10.1007/978-981-19-5888-5_4 DOI: https://doi.org/10.1007/978-981-19-5888-5_4
Bewley, J. D., & Black, M. (2013). Seeds: Physiology of development and germination. Springer Science+Business Media. https://doi.org/10.1007/978-1-4899-1002-8 DOI: https://doi.org/10.1007/978-1-4899-1002-8
Bewley, J. D., Bradford, K. J., Hilhorst, H. W. M., & Nonogaki, H. (2013). Seeds: Physiology of development, germination and dormancy (3rd ed.). Springer. https://doi.org/10.1007/978-1-4614-4693-4 DOI: https://doi.org/10.1007/978-1-4614-4693-4
Cheng, M., Guo, Y., Liu, Q., Nan, S., Xue, Y., Wei, C., Zhang, Y., Luan, F., Zhang, X., & Li, H. (2022). H₂O₂ and Ca²⁺ signalling crosstalk counteracts ABA to induce seed germination. Antioxidants, 11(8), 1594. https://doi.org/10.3390/antiox11081594 DOI: https://doi.org/10.3390/antiox11081594
Chu, C., Poore, R. C., Bolton, M. D., & Fugate, K. K. (2022). Mechanism of sugarbeet seed germination enhanced by hydrogen peroxide. Frontiers in Plant Science, 13, 888519. https://doi.org/10.3389/fpls.2022.888519 DOI: https://doi.org/10.3389/fpls.2022.888519
FAOSTAT. (2021). Crops and livestock products. Food and Agriculture Organization of the United Nations. https://www.fao.org/faostat
Finch-Savage, W. E., & Leubner-Metzger, G. (2006). Seed dormancy and the control of germination. New Phytologist, 171(3), 501–523. https://doi.org/10.1111/j.1469-8137.2006.01787.x DOI: https://doi.org/10.1111/j.1469-8137.2006.01787.x
Gong, Y., Zhang, D., Lv, J., Lv, P., Zhao, X., Sha, Q., Zhou, W., & Sun, Y. (2025). Breaking wild soybean seed physical dormancy: Optimal methods and seed coat structural changes. Genetic Resources and Crop Evolution, 72(7), 8533–8545. https://doi.org/10.1007/s10722-025-02464-2 DOI: https://doi.org/10.1007/s10722-025-02464-2
Hammed, L. A. (2012). Growth analysis of cashew seedlings as affected by nut size in the nursery. Nigerian Journal of Horticultural Science, 16, 1–8.
Hammed, L. A., & Adeyemi, E. A. (2005). Germination and seedling performance of cashew (Anacardium occidentale Linn.) as affected by nut-sowing orientations and cotyledon removal. Nigerian Journal of Horticultural Science, 10(1), 59–64. https://doi.org/10.4314/njhs.v10i1.3410 DOI: https://doi.org/10.4314/njhs.v10i1.3410
Jurdak, R., Launay-Avon, A., Paysant-Le Roux, C., & Bailly, C. (2022). Intracellular reactive oxygen species trafficking participates in seed dormancy alleviation in Arabidopsis seeds. New Phytologist, 234(4), 1470–1485. https://doi.org/10.1111/nph.18038 DOI: https://doi.org/10.1111/nph.18038
Kadjo, S. R., Koffi, K. K., Kouakou, C. K., Konan, A. J., Akanvou, L., Kouakou, K. L., & Zoro, B. I. A. (2025). Evaluation of growth performance of cashew (Anacardium occidentale L.) hybrid seedlings using vegetative traits. Australian Journal of Crop Science, 19(9), 917–927. https://doi.org/10.21475/ajcs.25.19.09.p14 DOI: https://doi.org/10.21475/ajcs.25.19.09.p14
Kimura, E., & Islam, M. A. (2012). Seed scarification methods and their use in forage legumes. Research Journal of Seed Science, 5(2), 38–50. https://doi.org/10.3923/rjss.2012.38.50 DOI: https://doi.org/10.3923/rjss.2012.38.50
Kubala, S., Wojtyła, Ł., Quinet, M., Lechowska, K., Lutts, S., & Garnczarska, M. (2015). Enhanced expression of the proline synthesis gene P5CSA in relation to seed osmopriming improvement of Brassica napus germination under salinity stress. Journal of Plant Physiology, 183, 1–12. https://doi.org/10.1016/j.jplph.2015.04.009 DOI: https://doi.org/10.1016/j.jplph.2015.04.009
Lamont, B. B., Gómez-Barreiro, P., & Newton, R. J. (2023). Seed dormancy revisited: Dormancy-release pathways and environmental interactions. Functional Ecology, 37(3), 534–558. https://doi.org/10.1111/1365-2435.14269 DOI: https://doi.org/10.1111/1365-2435.14269
Li, W., Niu, Y., Zheng, Y., & Wang, Z. (2022). Advances in the understanding of reactive oxygen species-dependent regulation on seed dormancy, germination, and deterioration in crops. Frontiers in Plant Science, 13, 826809. https://doi.org/10.3389/fpls.2022.826809 DOI: https://doi.org/10.3389/fpls.2022.826809
Longjam, R., & Kotiyal, A. (2024). Different pre-sowing treatments intensify the germination process and the seedling growth of fruit crops. International Journal of Advanced Biochemistry Research, 8(5), 541–546. https://doi.org/10.33545/26174693.2024.v8.i5g.1126 DOI: https://doi.org/10.33545/26174693.2024.v8.i5g.1126
Nazih, A., Baghour, M., Maatougui, A., Aboukhalid, K., Chiboub, B., & Bazile, D. (2024). Effect of gibberellic acid and mechanical scarification on the germination and seedling stages of Chenopodium quinoa Willd. under salt stress. Plants, 13(10), 1330. https://doi.org/10.3390/plants13101330 DOI: https://doi.org/10.3390/plants13101330
Olasan, O. J., Aguoru, C. U., Omoigui, L. O., & Iyorkaa, N. (2018). Characterization of groundnut seedlings using vigour and performance indices. Nigerian Journal of Genetics, 32, 81–87.
Rao, G. S. L. H. V. P., & Sebastian, S. (1994). Estimation of leaf area in tree crops. Journal of Plantation Crops, 22(1), 44–46.
Upretee, P., Bandara, M. S., & Tanino, K. K. (2024). The role of seed characteristics on water uptake preceding germination. Seeds, 3(4), 38. https://doi.org/10.3390/seeds3040038 DOI: https://doi.org/10.3390/seeds3040038
Varier, A., Vari, A. K., & Dadlani, M. (2010). The subcellular basis of seed priming. Current Science, 99(4), 450–456.
Wojtyla, Ł., Lechowska, K., Kubala, S., & Garnczarska, M. (2016). Different modes of hydrogen peroxide action during seed germination. Frontiers in Plant Science, 7, 66. https://doi.org/10.3389/fpls.2016.00066 DOI: https://doi.org/10.3389/fpls.2016.00066