For two or three decades, local knowledge has been one of the central themes in debates about development policy, especially at the project level. The 1980s and the first decade of this century saw a veritable boom in the specialized literature on local knowledge in the development context, often published under different under different terms (e.g., indigenous knowledge). On the one hand, this had to do with the usual paradigm shift in development policy, but on the other hand it was also influenced by the so-called participatory methods that became known by abbreviations such as RRA and PRA. In this specialized literature, local knowledge is usually considered to have a high potential for social and cultural sustainability. Often, huge quantities of information about different types of local knowledge (e.g., environmental, agricultural, and health knowledge) are produced, and it is frequently described as a kind of "resource". Such a view and interpretation can easily be perceived as utilitarian since it refers to the possibility of ultimately optimizing development policy instruments. Papers on local knowledge in institutions and organizations of technical cooperation are almost always written by academically trained personnel (often anthropologists), but when the authors are mere academics, publications usually take a very different direction. In the context of academic research, the documentation of local knowledge generally turns into an explicit or implicit critique of development policy scenarios and trends. Using an example from a rural area in southern Ceará state, Brazil, I will raise questions of local knowledge about agricultural biodiversity and technology and the local environments in the field of tension between academic research, local practice and transmission, and technical consultancy.