An Epidemiological Comparison of the US and Canadian <i>Plum pox virus</i> Eradication Programs

Fig. 1. Ripley’s L function analysis, a measure of spatial dependence, for PPV-positive Prunus blocks detected in Pennsylvania in 2000. A random labeling null hypothesis was used to account for the underlying pattern of all Prunus blocks.



Image from Plant Health Progress article:
An Epidemiological Comparison of the US and Canadian Plum pox virus Eradication Programs