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Abstract
The overarching goal of this dissertation was to evaluate the biophysical effects of integrated approaches to weed management, those that rely on practices in addition to herbicide-use, and to identify stakeholder perceptions of these approaches. Herbicide use is the primary, and often, exclusive, means of managing weeds within industrialized agronomic cropping systems. Given the scale at which these systems are operated, herbicide use represents the most effective and economically viable option for managing weeds. However, since the late 1960’s there have been an increasing quantity of cases of herbicide resistance in almost all weeds of economic importance. Herbicide resistance can be considered an outcome of natural selection. Continued reliance on herbicide-dominant weed management will lead to more resistant weeds, and resistance to more herbicide modes of action. In the Southeast United States, herbicide resistant weeds have become an existential threat to agricultural productivity and economic livelihoods. Finding non-herbicidal methods of limiting weed populations are imperative. The use of cover crops, a cultural management practice, may aid in this effort. Annual cover crops are species of grasses and forbs (often repurposed cereal and legume crop species) that are usually planted and established in seasonal periods that are asynchronous to cash crop growth. Herbicides and/or physical equipment are used to terminate annual cover crops, leaving a layer of residue into which a cash crop is then planted. Living mulches are variants of cover crops that are actively growing throughout the entire year. While both annual and perennial species have been used, the research described in this dissertation uses a perennial white clover species developed in Georgia called ‘Durana®’. Using both meta-analyses and a structured plot experiment, we evaluated the potential of both cultural practices to suppress weeds. This biophysical research was coupled with the use of a Q-methodology study employed to identify and describe stakeholder perceptions on integrated weed management approaches, such as those described above. Collectively, this represents an interdisciplinary effort to explore both biophysical and social dimensions of integrated weed management in Georgia and the Southeast US.