European pear rust control possibilities based on life cycle of the pathogen

Abstract: Pear is one of the most common fruit crop in Latvia and pear orchards occupy approximately 200 hectares. Although European pear rust caused by Gymnosporangium sabinae (Dicks.) G. Winter is not considered as a key problem in commercial pear orchards, during the last decade severe damages have occurred. Mainly severe damages were observed in home gardens or organic orchards. In recent years, the disease occurred also in some commercial orchards where applications of fungicides according to standard schemes appeared not to be sufficient for European pear rust control. The aim of this study was to evaluate current fungicide treatment schemes and their optimization for European pear rust control based on the pathogen life cycle and weather conditions. Data analysis showed statistically significant differences in disease severity among the years and it correlated with the time of first fungicide application and release of basidiospores.