Deep learning based weed detection and target spraying robot system at seedling stage of cotton field

•Thousands of weed images are acquired and medium scale dataset is built at seedling stage of cotton field scenario.•The proposed deep learning model for weed detection in cotton field at seedling stage is fast and accurate.•A vision system attached to the scene perception mechanism of intelligent robot in farmland maintains good performance.•The online weed detection and spraying experiments of the intelligent spraying robot in field condition are prospective.