Evaluating the Factors Affecting the Disease Progress of Ganoderma Basal Stem Rot Disease in Oil Palm Using OLS Regression Model and Wild Bootstrap Multiple Regression

Oil palm (Elaeis guineensis) is threatened by Ganoderma Basal Stem Rot (BSR) disease in almost all producing countries, including Malaysia. Although many kinds of research have been done to control the spread of the Ganoderma BSR disease, none showed a significant solution to stop the spread of the disease entirely. Therefore, this study aims to identify the factors affecting the progress of Ganoderma BSR disease in oil palm based on one of the disease triangle model. The data collection was done through surveys of "natural" epidemics. As study sites, three commercial oil palm plots in Sabah were chosen. During the BSR disease census, the Malaysian Palm Oil Board's (MPOB) standard operating procedure was used to determine the severity of each oil palm disease. A multiple linear regression (MLR) model using OLS estimation method was used to model the factors affecting the disease progress. Due to a violation of the MLR assumptions, the model was subsequently addressed using wild bootstrap multiple regression. The results show that nine factors have been identified as being crucial to the progression of the disease, which are the foliar symptoms less than 50%, foliar symptoms more than 50%, presence of rotting trunk, presence of unopened spears, number of hanging skirting, number of dry fronts, number of yellow fronts, presence of bunch and disease incidence. The findings can be used by researchers and planters to learn more about the elements that contribute to the progression of the BSR disease so that they can take appropriate action to minimize the disease's associated losses.