Early detecting damaged trees by pine wilt disease using DI(Detection Index) from portable near infrared camera.

Moon-IL Kim¹, Woo-Kyun Lee¹*, Tae-Hyub Kwon¹, Doo-Ahn Kwak¹,
You-Seung Kim² and Seung-Ho Lee³

 

Abstract: The purpose of this study is to examine the possibility of early detection of Pine Wilt Disease (PWD)
using NDVI (Normalized Difference Vegetation Index) from ADC (Agricultural Digital Camera) imageries. The
PWD induces the different patterns of reduction of NDVI between healthy trees and infected trees, due to the
withered leaves on the infected trees. Based on these phenomena, the Dl showing the NDVI variations of trees
by time series was employed to detect the infected trees. To find out the differences of Dl level between normal
and infected trees, Dis of trees from May to August in 2007 were calculated and these were analyzed with
GLM (General Linear Models) in SAS 9.2. As a result, the difference of Dl between in June and August shows
the most significant level (0.000 I). The discriminant analysis was performed between normal and infected trees,
using the Dl of June and August. As the result, hit ratio of trees and the accuracy of grouping with Jack-knife
method were shown 71.9% and 73.5%, respectively. These results showed that the Dl is effective to detect the
trees infected by the PWD and it is useful to prevent the PWD.

 

Key words: DI, early detection, GLM, NDVI, pine wilt disease