Dutch phytopathologist and mycologist.
Jan Hendrik Wakker (28 June 1859 – 26 July 1927) was a Dutch botanist and plant pathologist. He worked as a director of the sugarcane experimental station in Pasoeroean from 1892 to 1897. Wakker was born in Amsterdam and went to school along with included J.M. Janse, Jacques Perk and Willem Kloos. He then went to study under Hugo de Vries and J.C Costerus and received a doctorate in 1885 with research on adventitious buds. He then worked with Hugo de Vries, examining a disease of hyacinths caused by bacteria. He was among the first to demonstrate bacterial infections in plants. He then studie