Spatial and Temporal Distribution of <i>Iris yellow spot virus</i> and Thrips in Colorado Onion Fields

Fig. 2. Spatial distribution of thrips (upper row) and the corresponding incidence of iris yellow spot (IYS) (lower row) on 7 July (A), 25 July (B), 9 August (C), 18 August (D), and 31 August (E) from the Loma-North onion field in 2005 in Colorado. Dark green areas indicate where thrips density or incidence of IYSV was 0, while red indicate areas of highest thrips density (64.4/plant) or IYSV incidence (7.0%). Maps were produced from data interpolated using the inverse distance weighting technique based on the assumption that the interpolating surface should be influenced most by the nearby points and less by the more distant points (19).



Image from Plant Health Progress article:
Spatial and Temporal Distribution of Iris yellow spot virus and Thrips in Colorado Onion Fields