Islamic University Journal of Applied Sciences

Explainable Deep Learning Models for Citrus Leaf Disease Identification and Agricultural Decision Support

Sami Saad Albouq

Keywords: Citrus Leaf Diseases; Deep Learning; CNN, VGG16; Explainable AI; Grad-CAM; Agricultural Decision Support.

Major: Engineering

Sub Major: Numerical Methods & Computational Intelligence

https://doi.org/10.63070/jesc.2026.023; Received 25 December 2025; 15 February 2026; Accepted 10 April 2026; Available online 15 April 2026.
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Abstract

Citrus is a commercially important crop affected by diseases such as anthracnose, bacterial blight, and citrus canker, which damage trees and reduce fruit yield. Classical diagnosis is time-consuming and expert-dependent, limiting scalability. In this paper, we propose explainable deep learning models for multiclass citrus leaf disease detection, incorporating custom pre-processing and extensive data augmentation for robustness. A custom CNN and transfer learning-based VGG16 were fine-tuned on an augmented dataset of nine citrus leaf categories, including both healthy and unhealthy specimens. Performance was evaluated using accuracy, precision, recall, F1-score, and confusion matrices. The CNN achieved 97% accuracy, outperforming VGG16’s 95%, demonstrating the effectiveness of our preprocessing approach. For interpretability, Grad-CAM, SHAP, and LIME were uniformly applied to highlight symptom-relevant regions aligned with agronomic knowledge, enhancing transparency and user trust. The framework effectively combines predictability and interpretability, supporting practical, real-time, and sustainable agricultural decision systems.

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