Skip to content
Open access

Hybrid Feature Fusion and Bayesian-Optimized Ensemble Learning for Robust Citrus Disease Detection

Aug 2026 · International Journal of Engineering and Manufacturing · 0 citations

TL;DR

The combination of hybrid feature fusion, NCA-based feature optimization, and Bayesian-optimized ensemble classification leads to enhanced discriminative power, greater robustness, and better generalization performance for the system in citrus disease identification in a real-world agricultural setting, as demonstrated by the results.

Abstract

Detecting citrus diseases at an early stage is very important for ensuring fruit quality and minimizing production losses, as well as for raising awareness about sustainable agriculture. As a solution to this problem, the authors of this paper propose a hybrid feature-based citrus disease classification system that integrates deep learning representations, handcrafted descriptors, feature selection, and ensemble learning, all of which are tuned via Bayesian optimization. We perform tests on two real-world citrus disease datasets that differ greatly in nature: a four-class lemon dataset and a two-class orange dataset. Both datasets were collected under quite different environmental conditions, so they show diverse disease symptoms and varying background complexity. Deep semantic features were obtained by running a pretrained ResNet50 network. In addition to those, other complementary handcrafted features, such as color, texture, spatial, and statistical features, were extracted from the segmented infected areas. Together, the hybrid feature vector of 2082 dimensions was subjected to an optimization method known as Neighborhood Component Analysis (NCA). This technique selects 300 features that are most effective for discrimination while at the same time ensuring the preservation of class separability and the minimization of redundancy. For the classification task, two classifiers, namely Random Forest (RF) and Bayesian-Optimized Random Forest (BORF), were employed. The latter is based on Bayesian optimization to locate the model hyperparameters. To measure the model's performance in an unbiased manner, five-fold cross-validation was performed. Based on the experimental results, BORF can improve classification accuracy on the lemon dataset from 90.42% to 93.75% and on the orange dataset from 95.42% to 95.92% compared to the baseline RF classifier. Cross-validation mean accuracies of the proposed system were 93.75 ± 0.82% and 95.92 ± 0.47% for the lemon and orange datasets, respectively. Receiver Operating Characteristic (ROC) analysis provided class-specific area under the curve (AUC) values of 0.975 and 0.972 for the orange dataset, with a macro-averaged AUC of about 0.94 for the multi-class lemon dataset. The combination of hybrid feature fusion, NCA-based feature optimization, and Bayesian-optimized ensemble classification leads to enhanced discriminative power, greater robustness, and better generalization performance for the system in citrus disease identification in a real-world agricultural setting, as demonstrated by the results.

Read PDF

Similar papers

Conference Jul 2026

Deep Feature-Driven Learning Framework for Visual Diagnosis of Sunflower Crop Diseases Detection

Agricultural production is exposed to losses when plants became infected with diseases from the environment, which in turn threatens food security; therefore, having the ability to detect plant diseases early on gives farmers the opportunity to minimize the loss they incur. Sunflower (Helianthus annuus) is Ranking among other oilseed crops worldwide for total agricultural production, and it has a high risk of being affected by diseases that cause reduced crop yield and quality, e.g., Downy mildew, grey mould, and leaf scars. Disease detection using conventional methods usually involves visual inspections by trained personnel; this process, however, is very time consuming, subjective, and could produce numerous errors. To counteract these issues, this paper proposes a hybrid learning framework for plant disease detection that combines deep feature-driven image analysis with a combination of two classifiers used in an ensemble mode to create a single final classification. The use of MobileNetV2 will act as the feature extraction process for the hybrid learning framework, while the classifier portion of the hybrid learning framework will consist of two K-Nearest Neighbour classifiers. Classification using SVM and RF classifiers will be completed using a combination of ensemble voting. Grad-CAM (gradient-weighted class activation maps) will be used to improve the interpretability of the disease classification results by identifying affected areas on images. Test results for the hybrid learning framework reveal an overall accuracy of 98.8%, compared to the accuracy of the two classifiers used separately: 95.8% for CNN, 93% for SVM, and 96.0% for RF. The confusion matrix for the two classifiers shows a significant number of accurate classifications with minimal misclassifications. The proposed hybrid learning framework for plant disease detection provides an effective method for detecting plant diseases in real time, interpretable results, and potential for scalability.

Kshirsagar Soumya, Mr. G Sekhar Reddy, D. G. L. A. Babu et al. · 0 citations
Open access Jul 2026

Hybrid Deep Learning Architectures for Automated Mango Leaf Disease Detection

India is one of the biggest producers and exporters of mangoes in the world, yet its cultivation is persistently threatened diseases that reduce yield, fruit quality, and orchard longevity. Traditional disease diagnosis is based on agronomists' hand visual inspection, which is a laborious, subjective, and challenging technique to scale across vast plantations. This research provides a hybrid deep learning system that incorporates AlexNet and ResNet-50 for the automated classification of five commercially relevant mango leaf diseases: Bacterial Canker, Anthracnose, Powdery Mildew, Sooty Mould and Healthy foliage. Through a fused, jointly trained classification head, the suggested architecture combines the deep, residual feature hierarchies of ResNet-50 with the shallow, texture-sensitive representations learned by AlexNet, enabling the network to take advantage of complementary visual cues that neither backbone fully captures on its own. The hybrid model was implemented and trained using MATLAB. The trained model achieved a validation accuracy of 99.47%. Comparative analysis against standalone AlexNet, standalone ResNet-50, and other architectures reported in the recent mango plant-disease literature indicates that the hybrid fusion strategy offers a favourable balance of accuracy and convergence stability.

Ranu Solanki, D. Yadav · 0 citations
Conference Jul 2026

Multi-Plant Disease Classification using ResNet50-based Deep Ensemble Learning Framework

Agricultural productivity and food security are heavily impacted by plant diseases, and thus there is a high demand for accurate and automated plant disease detection that can be achieved by applying deep learning techniques. This research proposes a Multi-Model Ensemble Method Based on Deep Learning for multi-plant disease detection using ResNet50 to improve classification performance across multiple crop varieties. The proposed framework takes five important categories of plants into consideration including tomato, potato, grape, apple and maize, and 10 classes of healthy and diseased plants are generated from the PlantSeg dataset. The Anaconda platform was used along with Python to create a development environment that allows data preprocessing, augmentation, training and testing to be implemented efficiently. The proposed ensemble framework combines the feature extraction power of ResNet50 with several deep learning classifiers so as to obtain a good identification performance at different resolutions and environments. The proposed model performance is tested with the following metrics Accuracy, Precision, Inference Time, and Resolution quality and compared with MobileNetV2, YOLOv8 and the baseline CNN models. Experimental results show that the proposed ensemble ResNet50 framework achieves an accuracy of 98.7% and precision of 98.3%, which is about 6.4%, 4.8%, and 9.2% higher than that of MobileNetV2, YOLOv8, and CNN respectively. Moreover, the proposed method achieves high resolution disease localization capability with an inference time improvement of almost 18% compared with YOLOv8. The proposed system greatly improves the detection accuracy of the early stage and the calculation speed of the system, which is very suitable for smart agriculture applications and real-time monitoring of the health status of crops.

Suryateja Kothuru, Santhosh Kumar Medishetti · 0 citations
Conference Jul 2026

Deep Learning Techniques for Citrus Disease Detection: A Comprehensive Review

Citrus crops are economically vital worldwide, yet they remain highly susceptible to a range of infectious diseases that cause considerable yield and quality losses each year. Early and accurate disease identification is fundamental to sustainable orchard management and food security. Over the past decade, deep learning has emerged as the dominant paradigm for automated plant disease detection, surpassing traditional image-processing pipelines in both accuracy and scalability. This paper presents a comprehensive review of deep learning methodologies applied to citrus disease detection, covering convolutional neural networks (CNNs), attention mechanisms, lightweight architectures, object detection frameworks, multimodal fusion, and edge-computing deployment. Recent studies are critically analyzed with respect to model architecture, dataset characteristics, performance metrics, and deployment context. The review identifies prevailing trends including the shift toward lightweight models for edge devices, the integration of attention modules for fine-grained feature capture, and the growing adoption of multimodal and transformer-based approaches. Key open challenges such as limited data diversity, computational constraints in field deployments, and the need for domain-adaptive models are also discussed, along with prospective research directions. The findings serve as a reference for researchers and practitioners seeking to develop robust, real-time citrus disease detection systems.

Aniket K. Shahade, Vishal Jain, G. Manteghi et al. · 0 citations