Comparison of Imaging and Actual Measurement of Plant Height and Leaf Area of Cucumber Grafted Seedlings using LiDAR and Multispectral Camera

This study was conducted to develop the ability to determine seedling conditions by correlating image values with actual measurements, we investigated whether cucumber plant height and leaf area correlate by comparing LiDAR and multispectral seedling imaging data with actual measurements obtained via the destruction of seedlings.Cucumber plants were grafted using the 'Heukjong' (Cucurbita ficifolia, cv.Heukjong) stock and the 'Goodmorningbackdadagi,' 'Nakwonseongcheongjang', and 'Sinsedae' scions.Multispectral imaging was obtained before grafting, and at weeks 1, 2, and 3 after grafting.The overlapping leaf area per plug tray was calculated by subtracting the imaging measured values from the actual measured values.The result showed that the highest plant height and leaf area values were obtained when the 'Nakwonseongcheongjang' variety was grafted on to 'Heukjong', and the SPAD value, an indicator of chlorophyll content, was the highest for seedlings grafted with 'Sinsedae' scions on to 'Heukjong'.In experiments, the plant height of cucumber grafted seedlings showed a higher correlation in plug trays than in individual units, and the correlation between the actual value and the image value of the leaf area in plug tray units showed a high correlation of R 2 = 0.85 or higher, indicating that LiDAR and multispectral images can be used to predict plant height and leaf area in plug tray units.However, the overlapping area in plug tray units is larger than in individual units.As the number of weeks after grafting increases, the leaf area becomes wider and the overlapping area increases.When measuring leaf area in plug tray units, research is needed to correct the overlapping area of leaves to reduce the error between the image value and the actual value.