Spatial autocorrelation study of fatal yellowing in organic oil palm in the eastern Amazon

Abstract

The oil palm (Elaeis guineensis) is a very important source of vegetable oil worldwide. While oil palm cultivation is not currently economically significant in Brazil, there is immense growth potential for this crop in the Amazon region, with no need for deforestation. Fatal yellowing (FY) is a major phytosanitary barrier to the development of oil palm cultivation in the region. Many plantations have been devastated by FY, but its causes are unknown. The objective of this study was to analyze the spatial autocorrelation of FY in the oil palm crop by applying Moran’s Index (I). The experiment was carried out on a large farm (>8000 ha) in the municipality of Acará, in the state of Pará (Brazil), with 139 plots of oil palm of different genetic materials and ages. The number of diseased plants per plot has been recorded since 2001 and used in the analysis. A positive autocorrelation of disease incidence was calculated based on the observations of the current study. By calculation of the Local Moran’s I it was possible to identify the presence of high-incidence regions in the northeast and the central-west areas of the farm and low-incidence areas in the south and the north and in outlying plots. The approach described in this study was useful in identifying regions with the highest occurrence of FY, and could be useful in the management of this disease.