Longitudinal Analysis of symptom expression in esca disease grapevines

An analysis of symptom expression in esca infected grapevines was performed by focusing on the dynam-ics of each plant. A parametric statistical model was proposed to evaluate the probability that a plant would showesca symptoms at given values for a relevant set of factors (year, presence of symptoms in the previous year, presenceof plants with symptoms in the close neighborhood). The statistical tests of the hypotheses revealed that the consid-ered factors explained a large amount of the observed variability. In particular, the state of plants in the close vicinityis one of those factors. Thus we found evidence that there was an association between plant vicinity and esca symp-toms. Future developments of our model will include the factors field column and weather.