Spatial distribution of fatal yellowing cases in oil palm plantations in the Eastern Amazon

Abstract Fatal yellowing (FY) is a lethal and poorly understood disease that threatens the sustainability of oil palm ( Elaeis guineensis Jacq.) cultivation in the Amazon region. Despite decades of research, its etiology remains unknown, and its spatial dynamics are still unclear, particularly under different cultivation systems. This study aimed to characterize and compare the spatial distribution of FY cases in oil palm plantations under organic and conventional cultivation systems in the Eastern Amazon. Field data were collected monthly from December 2012 to March 2014 in four plots located in Acará, Pará State, Brazil. Each plant was evaluated for the presence or absence of FY symptoms, and geostatistical analyses were applied to assess spatial dependence and disease aggregation patterns using spherical, exponential, and Gaussian models. The results indicated a predominance of aggregated spatial distribution in both cultivation systems, with stronger spatial dependence observed in plots with higher FY incidence. The disease tended to cluster within a radius of up to 220 m, with hotspot formation often near access roads. These findings suggest the possibility of a biotic dissemination mechanism and support the development of targeted surveillance strategies. By quantifying the spatial behavior of FY, this study provides a technical basis for implementing localized monitoring and management practices in oil palm plantations, contributing to early detection and more effective disease control.