Open Access

ARTICLE

Dynamic Coefficient Triangular Greenness Index for Aerial Phenotyping in a Liberica Coffee Farm

Anton Louise P. De Ocampo^*

Department of Electronics Engineering, Batangas State University, Batangas City, 4200, Philippines

* Corresponding Author: Anton Louise P. De Ocampo. Email:

(This article belongs to the Special Issue: Progress, Challenges, and Opportunities in GIS 3D Modeling and UAV Remote Sensing)

Revue Internationale de Géomatique 2025, 34, 731-749. https://doi.org/10.32604/rig.2025.066185

Received 31 March 2025; Accepted 16 September 2025; Issue published 10 October 2025

Abstract

The effects of climate change are becoming more evident nowadays, and the environmental stress imposed on crops has become more severe. Farmers around the globe continually seek ways to gain insights into crop health and provide mitigation as early as possible. Phenotyping is a non-destructive method for assessing crop responses to environmental stresses and can be performed using airborne systems. Unmanned Aerial Systems (UAS) have significantly contributed to high-throughput phenotyping and made the process rapid, efficient, and non-invasive for collecting large-scale agronomic data. Because of the high complexity and cost of specialized equipment used in aerial phenotyping, such as multispectral and hyperspectral cameras as well as lidar, this study proposes a framework for implementing aerial phenotyping where chlorophyll estimation, leaf count, and coverage are determined using the RGB (Red, Green and Blue) camera native to a UAS. The study proposes the Dynamic Coefficient Triangular Greenness Index (DCTGI) for aerial phenotyping. Evaluation of the proposed DCTGI includes the correlation with chlorophyll content estimated using a Soil Plant Analysis Development (SPAD) chlorophyll meter on randomly sampled Liberica coffee seedlings. Analysis revealed a strong relationship between DCTGI values and chlorophyll estimates derived from SPAD measurements, with a Pearson’s correlation coefficient of 0.912. However, the study didn’t implement tissue-level validation and field-scale temporal analysis to assess seasonal variability. In addition, the SPAD meter provided the approximate nitrogen content together with the chlorophyll estimate.

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Keywords

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