Thesis (M.Sc.(Crop Science) North-West University, Mafikeng Campus, 2011

Bibliography: leaves 220-247.

Bibliography: leaves 220-247. / x, 247 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 2001

The following research developed an approach and methodology to simultaneously gather and integrate social and natural science farm system data of developing countries into one data base. The overall approach was based on Weber's theory of abstraction, which requires the identification of the broadest number of variables as possible. The first step to understanding the farm system was to overview a number of the key variables which represented a number of key farm components; the second step was to juxtapose and blend together the various forms of data in linear forms against a test variable of Striga infestation levels; the third step was to evaluate if the amount of knowledge gained in predicting Striga infestation levels was statistically significant by cross correlating soil nutrient levels, crop management approaches, farmers' perceptions of Striga infestation and spatial distances; the fourth step was to use parametric and non-parameterc analytical tools in conjunction with data compression to locate the best combination of parameters to better manage Striga. The final part of the process was to identify and integrate the crop, field and social data into a profile of farmer's who have the highest and lowest likelihood of being infested by Striga by using a soil nutrient concentration baseline as the indicator. The results were that natural and social science data could be successfully combined, integrated and have statistically significant cross correlations. These correlations indicate that specific spatial parameters combined with specific soil components, farmer's management and crop placement could be used as predictors of Striga infestation levels. As well the farmers' perception could be validated using natural science data.

This thesis modifies and enlarges on a theory that a separate center of plant domestication existed in the Lower Ohio Valley prior to the introduction of the Mesoamerican maize, beans, and squash complex. A shift from food-collecting to cultivation occurred around seasonally sedentary foci located along the region's waterways. A model for the development of a pre-maize cultigen-based subsistence system is suggested.This subsistence system provided the basis for the development and evolution of the Scioto Tradition within the Ohio Valley. The thesis questions the applicability of the mud-flat hypothesis to the region under consideration.

Diss. Uppsala : Sveriges lantbruksuniv., 2004.

Thesis (M.Sc.(Plant Production and Soil Science))--University of Pretoria, 2007. / Abstract in English. Includes bibliographical references (leaves 179 - 194).

Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph.D.)--University of Alberta, 1997. / Submitted to the Faculty of Graduate Studies and Research in partial fulfilment of the requirements for the degree of Doctor of Philosophy, Department of Anthropology. Also available online.