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dc.contributor.advisorSmeda, R. J. (Reid John), 1960-eng
dc.contributor.authorSmith, Chad Leeeng
dc.date.issued2009eng
dc.date.submitted2009 Springeng
dc.descriptionThe entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.eng
dc.descriptionTitle from PDF of title page (University of Missouri--Columbia, viewed on January 22, 2010).eng
dc.descriptionThesis advisor: Dr. Reid J. Smeda.eng
dc.descriptionIncludes bibliographical references.eng
dc.descriptionM.S. University of Missouri--Columbia 2009.eng
dc.descriptionDissertations, Academic -- University of Missouri--Columbia -- Agronomy.eng
dc.description.abstractThe advent of glyphosate-resistant corn in Missouri has changed traditional reemergence (PRE) followed by postemeregence (POST) herbicide programs to ones that predominately utilize glyphosate POST. POST only programs can allow early season weed competition. The objective was to determine the efficacy of one and two-pass programs using PRE and POST herbicides in glyphosate-resistant corn and to quantitate the nitrogen loss from various application timings in POST glyphosate weed control. The first study composed of one-pass and two-pass herbicide weed control programs. Weed control failures occurred 29% more often using one-pass systems compared to two-pass programs utilizing PREs and yield reductions occurred more often in one-pass systems. Overall, two-pass systems which included the use of a PRE herbicide resulted in more consistent weed control across all species than one-pass POST treatments. The second study consisted of PRE herbicide treatments to favor grass, broadleaf, or mixed weed populations at multiple glyphosate application timings. To document nitrogen loss, weed biomass, leaf chlorophyll meter readings, and stalk nitrate testing was measured. Grass weeds were more detrimental to yield than broadleaf weeds. Chlorophyll meter readings documented nitrogen deficiency between treatments. Corn leaf chlorophyll meter readings taken at tasseling correlated strongly to the resultant grain yield (R2 [greater than or equal to] .84). Higher year-end stalk nitrate accumulations were reflective of higher grain yield.eng
dc.format.extentvii, 107 pageseng
dc.identifier.merlin.b73398731eng
dc.identifier.oclc501320819eng
dc.identifier.otherSmithC-060209-T1556eng
dc.identifier.urihttp://hdl.handle.net/10355/6568eng
dc.publisherUniversity of Missouri--Columbiaeng
dc.relation.ispartofcollectionUniversity of Missouri--Columbia. Graduate School. Theses and Dissertationseng
dc.subject.lcshGlyphosateeng
dc.subject.lcshHerbicide-resistant cropseng
dc.subject.lcshCorn -- Weed controleng
dc.subject.lcshCrops -- Effect of nitrogen oneng
dc.titleWeed management and nitrogen loss in glyphosate-resistant corn (Zea mays)eng
dc.typeThesiseng
thesis.degree.disciplineAgronomy (MU)eng
thesis.degree.grantorUniversity of Missouri--Columbiaeng
thesis.degree.levelMasterseng
thesis.degree.nameM.S.eng


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