Spatiotemporal distribution of tomato plants naturally infected with leaf mold in commercial greenhouses

The distribution of tomato plants infected by Passalora fulva, causal agent of leaf mold, was analyzed by using Taylor's model and Iwao's model to assess the patterns of spatial distribution within the greenhouses. In Taylor's model, the sample variance (s (2)) of diseased plants newly recognized at each observation increased only slightly with mean density (m). In Iwao's model, the mean crowding (m*) of newly recognized diseased plants at each observation increased with m of diseased plants. The statistical analysis in this study suggests that new infections in greenhouses observed during this investigation tended to cluster around a diseased plant and that secondary infections occurred as independent cluster points.