ABSTRACT
Historically, tribal organization has been the basis of sector structure. Lately the exchange economy has had considerable influence, certainly on the agriculture but perhaps less on the community base underlying it. The development of internal markets superimposes a structure of production opportunities on the possibilities dictated by conditions of climate and soil. As economic development has drawn labor out of agriculture, capital has filled the vacuum and made the sector an important market for the chemical and machinery industries. The homogeneity of peasant agriculture in geographically identifiable areas bounded by natural conditions and tribal boundaries has major consequences for the methodology of both investigation and planning. By coincidence the number of production units in Sukuma agriculture, covering the largest tribal area in Tanzania, is of the same order of magnitude as the number in British agriculture.
