Rusty leaf

Even plants get ill. Plant diseases can be caused by viruses, microbes or parasites. The disease which a plant is suffering from can be established on the basis of deformities or specific discolorations. In the phytopathology (the study of plant diseases), fluid preparations of plants were used to teach students how to recognise the most important plant diseases.

Phytopathology professor Johanna Westerdijk

These three preparations are part of the extensive collection of phytopathology professor Johanna Westerdijk (1883-1961). The illustrations show preparations of sweet William affected by rust, cucumber infected with cucumber mosaic virus and peach infected with peach mosaic virus.

After 1980, the preparations passed into disuse and the collection became valuable in quite another way. Some of the diseases have become rare because of the use of herbicides and directed selected breeding and can only be found in Westerdijk's collection, which is also probably the only plant disease collection in Europe.

Professor Johanna Westerdijk, who was addressed by the male name of Hans, was a woman of striking personality. Between 1907 and 1952, she was Director of the Willie Commelin Scholten Institute for Phytopathology in Baarn. In 1917, she became professor by special appointment of phytopathology at Utrecht University. Her appointment marked a milestone for women's liberation, as she was the first female professor in the Netherlands. Under her supervision the phytopathological institute developed into an internationally renowned research laboratory.