Marssonina apple blotch, caused by the fungus Marssonina coronaria (teleomorph Diplocarpon mali) causes severe defoliation of apple trees in late summer, therefore leading to reduced yield and fruit quality as well as to a weakening of the trees over time. M. coronaria is one of the most important diseases in apples in Asia and has increasingly become a problem in European apple production in recent years, especially in low-input organic apple production. However, knowledge on the biology of M. coronaria in Europe is still scarce. The aim of our study was to gain a better understanding on spore dispersal in combination with disease progress in spring and early summer. To this end we developed a method that enables to capture and quantify M. coronaria spores in the field
