Abstract:Aiming to improve the accuracy and speed of evaluating tobacco seedling transplanting quality while addressing the limited computational resources of agricultural equipment, an improved, lightweight YOLO v8n model was proposed. Firstly, the conventional C2f module in the backbone network was replaced with a C2f_Ghost module. This modification significantly reduced memory footprint and parameter count without compromising accuracy, thereby facilitating deployment on mobile and edge devices. Next, omni-dimensional dynamic convolution (ODConv) was introduced to replace traditional convolutional stacks. This mitigated vanishing gradients and model degradation while enhancing the network's ability to distinguish seedlings from complex soil backgrounds. Furthermore, an efficient multi-scale attention (EMA) mechanism was integrated. Leveraging dynamic feature weighting, long-range dependence modeling, and lightweight computation, EMA effectively overcame challenges such as strong field background interference, significant scale variations of key features, and stringent real-time detection requirements. Experimental results on a custom dataset demonstrated that, compared with the baseline YOLO v8n, the proposed model improved precision, recall, mAP0.5, mAP0.5-0.95, and detection speed by 11.3%, 17.4%, 11.4%, 11.8%, and 4.62%, respectively. Concurrently, memory usage, parameter count, and floating-point operations (FLOPs) were decreased by 17.1%, 18.3%, and 31.7%, respectively. This research can provide a highly viable strategy for designing lightweight models in crop phenotypic detection, particularly for the precise quantitative assessment of transplanting quality, thereby advancing the digital management of modern tobacco agriculture.