Background : It is necessary to develop a diagnostic tool for the precision agriculture according to the change of agriculture environment. In particular, medicinal crops are often cultivated in poor areas such as mountains and valleys, and are susceptible to abnormal climates. Therefore, there is a need for a method that can diagnose the growth easily and with time. We conducted a study to investigate the possibility of remote sensing for 10 species of medicinal crops using unmanned aerial vehicles and multispectral images.
Methods and Results : This study was conducted in 0 - 4 times continuously cultivated field with 10 species of medicinal crops (Angelica gigas, A. koreana, A. tenuissiman, A. dahurica, A. acutiloba, A. polymorpha, Ledebouriella seseloides, Lithospermum erythrorhizon, Rhemannia glutinosa). Growth characteristics such as plant height, number of leaves, leaf length, leaf width, stem diamanter and number of stems were investigated between July 10 and July 16. The reflectance map of red (660 ㎚) and NIR (790 ㎚) was obtained using a UAV equipped with a multi-spectral sensor and NDVI [Normalized Difference Vegetation Index] was obtained with a Pix4D mapper. As the number of times of continuos cultivation increased, the growth and NDVI tend to decreased. 6 species of Angelica genus were positively correlated with growth characteristics such as plant height, leaf length, leaf width, and stem diameter and NDVI. Otherwise, there was no significant relationship between growth characteristics and NDVI in Ledebouriella seseloides, Lithospermum erythrorhizon, and Rhemannia glutinosa. This is because the difference in the growth according to time of continuos cultivation was not significant and the canopy structure tended to overlap with the upper and lower leaves.
Conclusion : NDVI is widely used as a useful tool for evaluating the canopy productivity and is highly correlated with the above-ground growth characteristics of 6 species of Angelica spp. It is necessary to develop the growth index suitable for the each species and to enhance the validity of growth index by examining the correlation under various cultivation conditions.