Image-based leaf SPAD value and chlorophyll measurement using a mobile phone: enabling accessible and sustainable crop management
9
Issued Date
2026-06-01
Resource Type
ISSN
13852256
eISSN
15731618
Scopus ID
2-s2.0-105039878089
Journal Title
Precision Agriculture
Volume
27
Issue
3
Rights Holder(s)
SCOPUS
Bibliographic Citation
Precision Agriculture Vol.27 No.3 (2026)
Suggested Citation
Anderson J., Boonyaves K., Okamoto H., Karaket N., Chuekong W., Garvie M., Chabang N., Osorio D., Supaibulwatana K. Image-based leaf SPAD value and chlorophyll measurement using a mobile phone: enabling accessible and sustainable crop management. Precision Agriculture Vol.27 No.3 (2026). doi:10.1007/s11119-026-10386-x Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/117063
Title
Image-based leaf SPAD value and chlorophyll measurement using a mobile phone: enabling accessible and sustainable crop management
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Corresponding Author(s)
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Abstract
Purpose: Leaf chlorophyll content is a critical indicator of plant health. On-farm monitoring is limited by the high cost and accessibility of specialised meters and laboratory assays. This study evaluates a smartphone-based imaging method (PhotoFolia) as a practical, low-cost alternative for accurately estimating leaf SPAD (Soil and Plant Analysis Development) values and chlorophyll content. Methods: Image-based estimates from the PhotoFolia mobile application were validated against standard laboratory assays and SPAD-502+ meter readings. The validation was conducted across four commercial rice varieties cultivated in Thailand. Results: The smartphone imaging method predicted SPAD values with a mean absolute error (MAE) of 1.2 units and chlorophyll concentrations with a mean absolute percentage error (MAPE) of 7.2% relative to laboratory benchmarks. Conclusion: With SPAD error approaching the industry ±1 unit standard and chlorophyll estimation remaining below a 10% relative error threshold, this approach demonstrates that ordinary mobile phones can serve as highly accessible, cost-effective tools for routine on-farm crop monitoring, eliminating the need for dedicated hardware. Highlights: Novel low-cost approach for chlorophyll assay and SPAD-value measurement using standard mobile phone. Achieves accuracy comparable to commercial tools. Eliminates need for specialised sensors or laboratory equipment. Impact: This study demonstrates that mobile phone-based image analysis can accurately estimate leaf SPAD and chlorophyll levels in rice under ambient lighting conditions, offering a low-cost, accessible tool for monitoring plant health.