The central argument of this thesis is that science and practice, as articulated in agricultural science in the Netherlands and its colonies, gradually broke apart. This process is visible in the organisation of agricultural research and education, as well as in the development of three major fields of agricultural science. These fields are (1) genetics and plant breeding applied to wheat in the Netherlands, (2) rice breeding in the Dutch East Indies and Surinam, and (3) agricultural statistics. Public-sector agricultural science in the Netherlands and its colonies institutionalised in various organisational forms and locations, but the major player in the network was the research and training institute in Wageningen. In 1863 a reorganisation of the Dutch education system anticipated a State Agricultural School ( Rijkslandbouwschool ), established in 1876. Initially the school was not part of the higher education system, but in the 1910s it was included in academia as an Agricultural College ( Landbouwhogeschool ). In 1986 the higher education system was again revised and the institute received the name Agricultural University ( Landbouwuniversiteit ). Therefore, the years 1863 and 1986 can be considered respectively as a starting point and culmination of agricultural science, therefore delineating the timeframe of this thesis.In the first chapter the relation between science and practice is further specified and connected to some theoretical notions, resulting in four points of attention for the analysis: 1) The influence of professional competition between agricultural scientists and other scientists in the shaping of agricultural science. 2) The role of government agencies in definitions of agricultural science, and in realising linkages between science and practice. 3) The effect of social interaction and group formation in organisations on the collective mindset ("institutional thinking"), affecting the direction of the development of agricultural science. 4) The role of social interactions between ...