Abstract:Aiming to address the challenges of small-target omission, insufficient feature extraction, and edge deployment difficulty in tobacco leaf disease detection, PCG-YOLO was proposed based on an improved YOLO 11s framework. A five-class tobacco disease dataset was constructed by using low-altitude UAV imaging. A P2 small-object detection layer was added to enhance shallow feature utilization. A customized C3k2_RVS module (C3k2_RepViTBlock_SimAM) was designed, where Rep_ViTBlock improves computational efficiency and SimAM enabled precise attention to lesion areas. Additionally, the lightweight GSConv module reduced model complexity. Ablation results showed that the P2 layer increased mAP50-95 by 4.7 percentage points, accompanied by a speed reduction of 14.8 f/s. GSConv reduced parameters by 13.8%, while C3k2_RVS enhanced both accuracy and speed. The proposed PCG-YOLO achieved a precision of 83.3%, an mAP50 of 92.4%, and an mAP50-95 of 77.1%, improving over the baseline by 4.2, 2.7, and 3.6 percentage points, respectively, with a detection speed of 64.1 f/s. Multi-model comparisons indicated that the proposed method achieved the best balance between accuracy and speed, outperforming others in mAP metrics. Detr-ResNet18 yielded higher precision at 84.2%, but suffered from slower speed and higher computational cost. YOLO v5s was faster and more lightweight, yet less accurate. Finally, the proposed method was deployed on a Jetson TX2 with TensorRT acceleration, achieving a precision of 82.9%, an mAP50 of 90.6%, an mAP50-95 of 76.3%, and a speed of 27.4 f/s, demonstrating strong recognition capability and stable operation on low-power edge platforms.