Modelling the effect of preharvest climate conditions on the incidence of two postharvest physiological disorders of 'Honeycrisp' apple

'Honeycrisp', a new apple cultivar, has high susceptibility to physiological disorders, including soft scald (SS) and soggy breakdown (SB). An important factor inducing these disorders is cool weather conditions at the end of the growing season. 'Honeycrisp' apples were harvested in Ontario (three sites), Québec (two sites) and in Nova Scotia (one site), in 2009 and 2010, in addition to data from Ontario (four sites), from 2002 to 2006. Analyses were made to link fruit quality to the weather at each site. A combination of dry conditions (for phenological stages BBCH 71-75), and cool conditions (BBCH 65-71 and 77.5-80) increased SS susceptibility. A combination of cool and wet conditions (BBCH 77.5-80) increased SB susceptibility. Models were developed for SS (RMSE = 18.71) and SB (RMSE = 6.88) predictions. Producers could use these in establishing more appropriate management of fresh fruit loads depending on regional and seasonal susceptibility to these disorders.