Estimation of plant density and plant height of winter wheat breeding material based on UAV digital images

Abstract 【Aims】 In order to obtain the plant density and plant height information of winter wheat breeding material quickly and accurately, it was of great practical significance for the growth monitoring and yield prediction of winter wheat breeding material. 【Method】 In this study, a drone equipped with a digital camera was used to obtain the drone digital orthophoto (DOM) and digital surface model (DSM) of winter wheat breeding material at the seedling stage, jointing stage, booting stage, flowering stage and grain filling stage. The coverage of winter wheat was extracted from drone images, and the relationship between coverage and plant density was established; the plant height estimation models of winter wheat breeding material were established respectively at jointing, booting, flowering and grain filling stages. Based on the ground measurement of winter wheat breeding material height (H), the accuracy of plant height of winter wheat breeding material extracted by DSM was verified.【Result】 The results showed that the winter wheat coverage extracted based on the UAV images at the seedling stage had a high correlation with the measured plant density, and the R2 was 0.8205. The new winter wheat cultivar H extracted by DSM was significantly correlated with the measured H, and the fitted R2 and RMSE of the predicted plant height and the measured value were 0.9554 and 6.3233 cm, respectively. 【Conclusion】 The results indicated that the use of UAV aerial imagery to predict the plant density and plant height of winter wheat breeding material has good applicability, and can provide technical reference for future crop phenotype information monitoring.