Determination of rubber-tree clones leaf diseases spectral using Unmanned Aerial Vehicle compact sensor

Abstract

Currently, one of the remote sensing platform that adequatly been used is Unmanned Aerial Vehicle (UAV) which suitable in monitoring and mapping for agriculture sector at large area payload by compact sensor. Thus, this study is deploy the UAV compact sensor to identify the characteristics of rubber tree clone leaf diseases based on two groups of spectral wavelength which is visible (RGB: 0.4 μm - 0.7 μm) and near infrared (NIR: 0.7μm - 2.0 μm), respectively. Spectral obtained using UAV platform is then to be validated with ground observation handheld spectroradiometer. Eight types of rubber tree clones leaf at three different conditions (healty, unhealty and severe) were randomly selected within the 9.4 hectare Experimental Rubber Plot, Rubber Research Institute of Malaysia (RRIM), Kota Tinggi, Johor whereby consist RRIM 2000 series, RRIM 3000 series and PB series, respectively. As a result, this study has found that the spectral trend based on UAV compact sensor from eight different types of rubber tree clones leaf shows the similarity to the general basic vegetation spectral in transition from blue to NIR spectral. However, referring to spectral obtained from handheld spectroradiometer there is no drastically changes of spectral in visible region but drastically increase in NIR region. Thus, this study has conclude that the spectral signature characteristics for healthy, unhealthy and severe for leaf diseases from every single rubber tree clones can be identified obviously in NIR region using UAV compact sensor.