Automated seedling vigor estimation in cucumbers using digital image processing
Main Article Content
Abstract
Background and Objective: Farmers often rely on experience rather than quantitative indicators to determine seedling quality, resulting in inefficiencies in resource allocation. This study aimed to (1) compare seedling vigor and growth characteristics between open-pollinated (OP) and F1 hybrid cucumber seed types, and (2) develop a non-destructive predictive model for seedling vigor estimation based on digital image analysis.
Methodology: Seedling images were acquired under controlled LED lighting using a 5 MP digital camera positioned 30 cm above 14-day-old seedlings. A YOLOv8-based object detection model was applied to detect and isolate true leaf regions, from which pixel count and RGB color values were extracted as input features for a multiple linear regression model to predict the seedling vigor index (SVI).
Main Results: The YOLOv8 object detection model achieved a mean average precision (mAP@0.5) of 96.00%, precision of 93.40%, and recall of 94.40% in detecting true leaves. Multiple linear regression analysis was conducted using the Scikit-learn library in Python. Scikit-learn provides regression-based machine learning algorithms, including multiple linear regression. The equation was then applied to the training and test sets, using the pixel values of true leaves as the independent variable and SVI as the dependent variable. Using multiple regression analysis, the trained model generated the equation SVI = -2.27 + (2.84 × 10-5 × pixel) + (3.48 × 10-5 × R) + (-7.49 × 10-2 × G) + (2.06 × 10-1 × B), R2 = 0.57 and RMSE = 1.10. The model achieved the test set, r = 0.79 and RMSE = 1.34. The model performance showed a correlation coefficient of 0.85 for OP data and 0.91 for F1 hybrid data.
Conclusions: The results demonstrate that digital image processing combined with object detection provides a non-destructive and effective approach to estimate seedling vigor quality. The predictive models developed from OP and F1 hybrid datasets indicate potential application in precision agriculture for automated seedling quality assessment and transplanting decision support.
Article Details

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
References
Alizadeh, M.A., H.A. Arab, R. Tabaie, M. Nasiri and A.A. Jafari. 2016. Evaluation of seed emergence, seedling vigor enhancement of some populations from Satureja bachtiarica with chemical, mechanical and physiological treatment. Plant Breed. Seed Sci. 74: 37–44. https://doi.org/10.1515/plass-2016-0013.
Dell’Aquila, A. 2009. Digital imaging information technology applied to seed germination testing. A review. Agron. Sustain. Dev. 29: 213–221. https://doi.org/10.1051/agro:2008039.
Demir, I. and K. Mavi. 2008. Seed vigour evaluation of cucumber (Cucumis sativus L.) seeds in relation to seedling emergence. Res. J. Seed Sci. 1(1): 19–25. https://doi.org/10.3923/rjss.2008.19.25.
Ellis, R.H. and E.H. Roberts. 1980. Improved equations for the prediction of seed longevity. Ann. Bot. 45(1): 13–30. https://doi.org/10.1093/oxfordjournals.aob.a085797.
Fehr, W.R. 1987. Principles of Cultivar Development: Theory and Technique. Macmillan Publishing Company, New York, USA.
ISTA (International Seed Testing Association). 2024. International Rules for Seed Testing. International Seed Testing Association, Wallisellen, Switzerland.
Jocher, G., A. Chaurasia and J. Qiu. 2023. Ultralytics YOLOv8 (Version 8.0.0) [Computer Software]. GitHub. Available Source: https://github.com/ultralytics/ultralytics.
Kaewsorn, P. and R. Sermsak. 2023. Application of digital image processing for seedling vigor estimation of primed tomato seed. Asia Pac. J. Sci. Technol. 28(2): APST-28-02-03. https://doi.org/10.14456/apst.2023.19.
Koirala, A., K.B. Walsh, Z. Wang and C. McCarthy. 2019. Deep learning for real-time fruit detection and orchard fruit load estimation: Benchmarking of ‘MangoYOLO’. Precis. Agric. 20: 1107–1135. https://doi.org/10.1007/s11119-019-09642-0.
Matthews, S. and A. Powell. 2006. Electrical conductivity vigor test: Physiological basis and use. Seed Testing International. 131: 32–35.
Matthews, S., E. Noli, I. Demir, M. Khajeh-Hosseini and M.H. Wagner. 2012. Evaluation of seed quality: From physiology to international standardization. Seed Sci. Res. 22(S1): S69–S73. https://doi.org/10.1017/S0960258511000365.
McDonald, M.M. and J.D. Lubell-Brand. 2024. F1 hybrid seed can enhance cannabis crop uniformity and yield. HortScience. 59(12): 1795–1799. https://doi.org/10.21273/HORTSCI18197-24.
Min, S.H., K. Kaewtrakulpong, T. Phaosang and R. Sermsak. 2022. Image processing method to check maturity index of ‘SEIN TA LONE’ mango in Myanmar. Suranaree J. Sci. Technol. 29(4): 0020017.
Olechowska, E., R. Słomnicka, K. Kaźmińska, H. Olczak-Woltman and G. Bartoszewski. 2022. The genetic basis of cold tolerance in cucumber (Cucumis sativus L.)—the latest developments and perspectives. J. Appl. Genet. 63(4): 597–608. https://doi.org/10.1007/s13353-022-00710-2.
Pedregosa, F., G. Varoquaux, A. Gramfort, V. Michel, B. Thirion, O. Grisel, M. Blondel, P. Prettenhofer, R. Weiss, V. Dubourg, J. Vanderplas, A. Passos, D. Cournapeau, M. Brucher, M. Perrot and E. Duchesnay. 2011. Scikit-learn: Machine learning in Python. J. Mach. Learn. Res. 12(85): 2825–2830.
Redmon, J., S. Divvala, R. Girshick and A. Farhadi. 2016. You Only Look Once: Unified, real-time object detection, pp. 779–788. In: Proceedings of the 2016 IEEE Conference on Computer Vision and Pattern Recognition, June 27–30, 2016, Nevada, USA.
Salama, K. 2024. Optimization of regression models using machine learning: A comprehensive study with Scikit-learn. IUSRJ. 5(16): 119–129. https://doi.org/10.59271/s45500.024.0624.16.
Samiei, S., P. Rasti, J.L. Vu, J. Buitink and D. Rousseau. 2020. Deep learning-based detection of seedling development. Plant Methods. 16: 103. https://doi.org/10.1186/s13007-020-00647-9.
Shen, Y., Z. Yang, Z. Khan, H. Liu, W. Chen and S. Duan. 2025. Optimization of improved YOLOv8 for precision tomato leaf disease detection in sustainable agriculture. Sensors. 25(5): 1398. https://doi.org/10.3390/s25051398.
Staub, J.E., M.D. Robbins and T.C. Wehner. 2008. Cucumber, pp. 241–282. In: J. Prohens and F. Nues, (Eds), Handbook of Plant Breeding. Springer, New York, USA.
Syed, T.N., L. Jizhan, Z. Xin, Z. Shengyi, Y. Yan, S.H.A. Mohamed and I.A. Lakhiar. 2019. Seedling-lump integrated non-destructive monitoring for automatic transplanting with Intel RealSense depth camera. Artif. Intell. Agric. 3: 18–32. https://doi.org/10.1016/j.aiia.2019.09.001.
Zendehdel, N., H. Chen and M.C. Leu. 2023. Real-time tool detection in smart manufacturing using You-Only-Look-Once (YOLO)v5. Manuf. Lett. 35: 1052–1059. https://doi.org/10.1016/j.mfglet.2023.08.062.