Comparison of visual disease assessment versus GIS/remote sensing methods to accurately detect the epicenters of Soybean rust foci

Abstract

A key question in plant pathology forensics is to determine whether or not the introduction of a new plant pathogen was the result of a deliberate, accidental, or natural event. Another important aspect of plant pathology forensics is to locate the epicenters of disease foci to look for forensics evidence, such as the presence or absence of substances that should not be present in the field (e.g. unique isolates, Tween-20, gelatin, syringes, Aluminum foil etc.). Soybean field plots (21 m x 21 m) were established in Quincy, FL. A single soybean plant infected with soybean rust was placed in the center of each plot to initiate disease foci. To quantify the spatial and temporal expansion of soybean rust disease foci, each plot was subdivided into 49 (7 x 7) 9 m2. quadrats and each quadrat was visually assessed for disease severity. Focal expansion was also quantified using satellite imagery. Disease severity and satellite image intensity maps were generated and analyzed using ArcGIS 10.3.1 software. Remote sensing/GPS/GIS technologies predicted the estimated rust foci epicenters to be within 1.5 m of the actual epicenters. The predicted GPS epicenters, based upon visual severity assessments, were estimated to be 2.46 m from the actual epicenters. Thus, remote sensing/GPS/GIS technologies have tremendous potential to more accurately and noninvasively determine where (epicenters) to search for forensic evidence within affected fields.

Publication
In APS North Central Division Meeting
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