|Dallot, S. - USDA-ARS-USHRL|
|Labonne, G. - ENSA-INRA|
|Quiot, J. B. - ENSA-INRA|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2003
Publication Date: December 1, 2003
Citation: Dallot, S., Gottwald, T., Labonne, G., Quiot, J. B. 2003. Spatial Pattern Analysis of Sharka Disease (PPV-M Strain) in Peach Orchards in Southern France. Phytopathology 93:1543 Technical Abstract: Individual <i>Plum pox virus</i> strain M infections were monitored visually during one to 3 years in 18 peach plots. The spatial pattern of the disease was investigated using binary data directly or after parsing the data in quadrats of 4, 9 or 16 trees. Ordinary runs demonstrated minimal aggregation of adjacent symptomatic trees. Beta-binomial analysis indicated overdispersion of infected trees for all quadrat sizes in 15 plots and the binary power law showed that intensity of aggregation was a function of incidence. Spatial relationships among quadrats were evaluated by spatial autocorrelation and SADIE analysis. The two methods were in good agreement and showed significant aggregation in a majority of data sets. Local areas of influence of PPV spread and relationships at longer distances were further investigated. Combined results indicated a wide range of spatial patterns of PPV-M infected trees. Factors that may have influenced such patterns, like the mechanisms of primary disease introduction, the diversity of aphid species and the structure of the orchards will be discussed.