Acta Agriculturae Zhejiangensis ›› 2022, Vol. 34 ›› Issue (9): 2032-2042.DOI: 10.3969/j.issn.1004-1524.2022.09.22

• Biosystems Engineening • Previous Articles     Next Articles

Automatic counting of maize plants based on unmanned aerial vehicle (UAV) 3D point cloud

JIANG Youyi1(), ZHANG Chengjian1,2,3, HAN Shaoyu2,3, YANG Xiaodong2,3, YANG Guijun2,3, YANG Hao2,3,*()   

  1. 1. College of Geomatics, Xi’an University of Science and Technology, Xi’an 710054, China
    2. Key Laboratory of Quantitative Remote Sensing in Agriculture, Ministry of Agriculture and Rural Affairs, Beijing Research Center for Information Technology in Agriculture, Beijing 100097, China
    3. National Engineering Research Center for Information Technology in Agriculture, Beijing 100097, China
  • Received:2021-03-24 Online:2022-09-25 Published:2022-09-30
  • Contact: YANG Hao

Abstract:

Plant counting is one of the most commonly used methods for farmers and breeding experts to evaluate crop growth status and management practices throughout the crop growing season, which can be used for reasonable field planning and management. In view of the lack of high-throughput methods to obtain the number of maize plants in the high-density planting experimental area, this study used the unmanned aerial vehicle (UAV) remote sensing platform to obtain the digital images and light detection and ranging (LiDAR) point cloud data of 314 maize high-density breeding plots with different genotypes in the field, and developed a fixed window local maximum algorithm combined with maize three-dimensional spatial information. The automatic detection of the number of plants in high density maize breeding plot was realized, and the detection accuracy based on the two different data sources was compared. Based on the plant height information in the crop height model (CHM), the method detected the seed points of each maize plant by using local maximum filter with a fixed window size, and then we spatially matched the detected seed points with the position of maize interpreted visually to evaluate the accuracy. The results showed that the comprehensive detection accuracy of three spatial resolutions CHM based on UAV digital images was 81.30%, 83.11% and 78.93% respectively, and the comprehensive accuracy of UAV-LiDAR was 82.33%, 88.66% and 81.46% respectively. The CHM, based on the two different data sources had the best detection accuracy when the spatial resolution was 0.05 m. In addition, when the spatial resolution was the same, LiDAR performsed better than UAV digital images. But when the demand for detection accuracy was not high, the digital sensor showed greater potential in field management because of its cheap price and easy to operate. This study realized the automatic counting of maize plant number in dense planting maize breeding experimental area, which provided a basis for phenotypic screening, field management and accurate yield estimation.

Key words: automatic counting, unmanned aerial vehicle, high-throughput, local maximum, canopy height model, field breeding

CLC Number: