This study aimed to discover if the incidence differences between three regions in the State of São Paulo, Brazil could be related to different dynamics of Citrus Variegated Chlorosis (CVC) progress. Three areas of the State (Northwest, Center and South) were evaluated by visual assessments performed two times a month for two years. For each evaluation all plants were inspected and designated as diseased or healthy. Nine models were fit to each CVC progress curve, and three were fit to segments of original curves. Also, first and second derivatives were estimated for each curve. A good fit was obtained for segments of original curves. First and second derivatives showed many peaks over time. Most of those peaks occurred during the spring and summer months. Our hypothesis is that derivative peaks are related to flush emission peaks, considering that new sprouts are the preferred feed sites of Xylella fastidiosa vectors.
