Survival of pathogens after dormancy in apple tree twigs indicates potential risk as source of inoculum

Several diseases are difficult to control specially in subtropical regions and perennial hosts where the pathogen survive easily within plant. The aim of this study was identify which pathogens surviving after end one season at beginning next inform represent potential risk as primary inoculum season. Survival on apple tree twigs evaluated during dormancy vegetative growth four orchards located two main production regions: Palmas metropolitan region Curitiba, Paraná State, Brazil. For purpose, 10 cm long asymptomatic were collected from randomly selected plants, 24 per Half left directly (without disinfection) humid chambers for 30 days 25ºC. other half disinfected kept a freezer 12 hours -16ºC by Over Night Freezing Incubation Technique (Onfit) then chamber fungi Colletotrichum sp., Botryosphaeria Alternaria Fusarium sp. detected sampled dates methodologies all regions. Neonectria ditissima only both Palmas. genera found confirmed molecularly BLASTn pathogenic wounded fruits cultivar ‘Gala’. Our results indicate that winter treatment throughout season, being sources infections flowers fruits, cause important bitter rot, fruit white black rots, possibly rots have not been extensively studied