Foreword.

Highlights from the article: One century ago, on 10 February 1917, Johanna Westerdijk delivered her inaugural speech at Utrecht University entitled "New directions in phytopathological research". As Westerdijk played also an important role in promoting phytopathology as a science field at the universities of Amsterdam and Wageningen, we decided to bring together a collection of papers that are a showcase of the impact Johanna Westerdijk had on the development of phytopathology. Graph: Fig. 1First Dutch female professor Johanna Westerdijk in the Utrecht University Hall after her inaugural lecture ' New directions in phytopathological research' on 10 February 1917.