{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/19271"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/19271","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Nitrate accumulation in hydroponically-grown lettuce cultivars and relationship to nitrogen supply","abstract":"The research in this thesis is made up of three related experiments, each concerned with nitrate (NO$\\sb{3-})$ accumulation and reduction in hydroponically-grown lettuce (Lactuca sativa L.), and its relationship to various aspects of N supply, including solution NO$\\sb{3-}$ concentration, the nitrate:ammonium solution ratio, and the interaction between solution flow rate and NO$\\sb{3-}$ fertilization level.","abstract_html":"The research in this thesis is made up of three related experiments, each concerned with nitrate (NO$\\sb{3-})$ accumulation and reduction in hydroponically-grown lettuce (Lactuca sativa L.), and its relationship to various aspects of N supply, including solution NO$\\sb{3-}$ concentration, the nitrate:ammonium solution ratio, and the interaction between solution flow rate and NO$\\sb{3-}$ fertilization level.","abstract_has_math":true,"creators":["Al-Redhaiman, Khalid Nasser"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Horticulture","degree_department":null,"school":null,"contributors":["Swiader, John M."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T12:02:18Z","date_published":"2011-05-07T12:02:18Z","updated_at":"2026-07-22T22:25:12Z","subjects":["Agriculture, Agronomy","Biology, Plant Physiology"],"languages":["eng"],"rights":["Copyright 1996 Al-Redhaiman, Khalid Nasser"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["9780591087642","AAI9702438","(UMI)AAI9702438"],"render_values":[{"text":"9780591087642","href":null,"code":true},{"text":"AAI9702438","href":null,"code":true},{"text":"(UMI)AAI9702438","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/19271","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Swiader, John M."]},{"key":"dc:creator","label":"Author","values":["Al-Redhaiman, Khalid Nasser"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T12:02:18Z","10000-01-01","1996"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Horticulture"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Agriculture, Agronomy","Biology, Plant Physiology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1996 Al-Redhaiman, Khalid Nasser"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["9780591087642","AAI9702438","(UMI)AAI9702438","http://hdl.handle.net/2142/19271"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The research in this thesis is made up of three related experiments, each concerned with nitrate (NO$\\sb{3-})$ accumulation and reduction in hydroponically-grown lettuce (Lactuca sativa L.), and its relationship to various aspects of N supply, including solution NO$\\sb{3-}$ concentration, the nitrate:ammonium solution ratio, and the interaction between solution flow rate and NO$\\sb{3-}$ fertilization level.","In the first experiment, significant effects from both solution NO$\\sb{3-}$ rate and genotype influenced tissue NO$\\sb{3-}$ concentrations. A sustained concentration of 1.0 mM NO$\\sb{3-}$ in solution was adequate to support lettuce growth, as there was very little response in either fresh or dry shoot weight with increasing NO$\\sb{3-}$ supply up to 5.0 and 15.0 mM NO$\\sb{3-}.$ In leaves, NRA showed a curvilinear response to increasing solution NO$\\sb{3-}$ rates, with highest NRA at 5.0 mM solution NO$\\sb{3-}.$ At low levels of solution N supply (0.5 and 1.0 mM NO$\\sb{3-})$ just about all the N in the leaves of each cultivar was in reduced form, however, as the solution NO$\\sb{3-}$ rate increased to 5.0 and 15.0 mM, RN/TN values decreased, and differences among cultivars for in situ NO$\\sb{3-}$ assimilation became greater, with RN/TN values higher romaine cultivars than in butterhead cultivars.","In the second experiment, tissue NO$\\sb{3-}$ concentrations in hydroponically-grown lettuce were reduced significantly with increasing NH$\\sb{4+}$:NO$\\sb{3-}$ ratios in the nutrient; however, effects of mixed-N nutrition on plant growth response varied considerably, depending on cultivar. With increasing solution NH$\\sb{4+}$:NO$\\sb{3-}$ ratios up to 50:50 (in a 15.0 mM N solution), shoot NO$\\sb{3-}$ concentrations in romaine lettuce at full head development were reduced approximately 58% (52% on a fresh weight basis), while shoot dry weights increased 46% (28% fresh weight). In butterhead cultivars, a solution NH$\\sb{4+}$:NO$\\sb{3-}$ ratio of 50:50 decreased shoot NO$\\sb{3-}$ concentrations 58% (54% fresh weight basis), but shoot growth was also reduced 9% (15% fresh weight basis). In both leaves and roots, NRA decreased with increasing proportion of NH$\\sb{4+}$ in the nutrient solution, beginning at a solution NH$\\sb{4+}$:NO$\\sb{3-}$ ratio of 25:75 in leaves, and 0:100 NH$\\sb{4+}$:NO$\\sb{3-}$ in roots.","In the third experiment, significant interactions between solution flow rate and NO$\\sb{3-}$ supply affected shoot NO$\\sb{3-}$ concentrations. At 0.5 mM solution NO$\\sb{3-},$ leaf NO$\\sb{3-}$ concentrations increased with increasing solution flow rate up to 1000 ml min$\\sp{-1},$ and then tended to either level off or decrease slightly. In plants supplied with 10.0 mM NO$\\sb{3-},$ leaf NO$\\sb{3-}$ levels were relatively unaffected by solution flow rate. Lettuce shoot weights increased with increasing solution flow rate up to 1000 ml min$\\sp{-1}$ at the Low NO$\\sb{3-}$ supply, and up to 25 ml min$\\sp{-1}$ in plants grown with 10.0 mM NO$\\sb{3-}.$ Both actual and potential NRA in leaves was unaffected by solution flow rate. Although actual NRA in leaves was significantly higher at 10.0 mM solution NO$\\sb{3-}$ than at 0.5 mM NO$\\sb{3-},$ there was little or no effect of NO$\\sb{3-}$ supply rate on potential NRA in leaves. (Abstract shortened by UMI.)","Made available in DSpace on 2011-05-07T12:02:18Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9702438.pdf: 4081739 bytes, checksum: ee5b9faac86a732cca4ef5fa89645127 (MD5) Previous issue date: 1996","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:35:49Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:14:15-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Nitrate accumulation in hydroponically-grown lettuce cultivars and relationship to nitrogen supply"]}]}],"canonical_facts":{"dc:contributor":["Swiader, John M."],"dc:creator":["Al-Redhaiman, Khalid Nasser"],"dc:date":["2011-05-07T12:02:18Z","10000-01-01","1996"],"dc:description":["The research in this thesis is made up of three related experiments, each concerned with nitrate (NO$\\sb{3-})$ accumulation and reduction in hydroponically-grown lettuce (Lactuca sativa L.), and its relationship to various aspects of N supply, including solution NO$\\sb{3-}$ concentration, the nitrate:ammonium solution ratio, and the interaction between solution flow rate and NO$\\sb{3-}$ fertilization level.","In the first experiment, significant effects from both solution NO$\\sb{3-}$ rate and genotype influenced tissue NO$\\sb{3-}$ concentrations. A sustained concentration of 1.0 mM NO$\\sb{3-}$ in solution was adequate to support lettuce growth, as there was very little response in either fresh or dry shoot weight with increasing NO$\\sb{3-}$ supply up to 5.0 and 15.0 mM NO$\\sb{3-}.$ In leaves, NRA showed a curvilinear response to increasing solution NO$\\sb{3-}$ rates, with highest NRA at 5.0 mM solution NO$\\sb{3-}.$ At low levels of solution N supply (0.5 and 1.0 mM NO$\\sb{3-})$ just about all the N in the leaves of each cultivar was in reduced form, however, as the solution NO$\\sb{3-}$ rate increased to 5.0 and 15.0 mM, RN/TN values decreased, and differences among cultivars for in situ NO$\\sb{3-}$ assimilation became greater, with RN/TN values higher romaine cultivars than in butterhead cultivars.","In the second experiment, tissue NO$\\sb{3-}$ concentrations in hydroponically-grown lettuce were reduced significantly with increasing NH$\\sb{4+}$:NO$\\sb{3-}$ ratios in the nutrient; however, effects of mixed-N nutrition on plant growth response varied considerably, depending on cultivar. With increasing solution NH$\\sb{4+}$:NO$\\sb{3-}$ ratios up to 50:50 (in a 15.0 mM N solution), shoot NO$\\sb{3-}$ concentrations in romaine lettuce at full head development were reduced approximately 58% (52% on a fresh weight basis), while shoot dry weights increased 46% (28% fresh weight). In butterhead cultivars, a solution NH$\\sb{4+}$:NO$\\sb{3-}$ ratio of 50:50 decreased shoot NO$\\sb{3-}$ concentrations 58% (54% fresh weight basis), but shoot growth was also reduced 9% (15% fresh weight basis). In both leaves and roots, NRA decreased with increasing proportion of NH$\\sb{4+}$ in the nutrient solution, beginning at a solution NH$\\sb{4+}$:NO$\\sb{3-}$ ratio of 25:75 in leaves, and 0:100 NH$\\sb{4+}$:NO$\\sb{3-}$ in roots.","In the third experiment, significant interactions between solution flow rate and NO$\\sb{3-}$ supply affected shoot NO$\\sb{3-}$ concentrations. At 0.5 mM solution NO$\\sb{3-},$ leaf NO$\\sb{3-}$ concentrations increased with increasing solution flow rate up to 1000 ml min$\\sp{-1},$ and then tended to either level off or decrease slightly. In plants supplied with 10.0 mM NO$\\sb{3-},$ leaf NO$\\sb{3-}$ levels were relatively unaffected by solution flow rate. Lettuce shoot weights increased with increasing solution flow rate up to 1000 ml min$\\sp{-1}$ at the Low NO$\\sb{3-}$ supply, and up to 25 ml min$\\sp{-1}$ in plants grown with 10.0 mM NO$\\sb{3-}.$ Both actual and potential NRA in leaves was unaffected by solution flow rate. Although actual NRA in leaves was significantly higher at 10.0 mM solution NO$\\sb{3-}$ than at 0.5 mM NO$\\sb{3-},$ there was little or no effect of NO$\\sb{3-}$ supply rate on potential NRA in leaves. (Abstract shortened by UMI.)","Made available in DSpace on 2011-05-07T12:02:18Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9702438.pdf: 4081739 bytes, checksum: ee5b9faac86a732cca4ef5fa89645127 (MD5) Previous issue date: 1996","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:35:49Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:14:15-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["9780591087642","AAI9702438","(UMI)AAI9702438","http://hdl.handle.net/2142/19271"],"dc:language":["eng"],"dc:rights":["Copyright 1996 Al-Redhaiman, Khalid Nasser"],"dc:subject":["Agriculture, Agronomy","Biology, Plant Physiology"],"dc:title":["Nitrate accumulation in hydroponically-grown lettuce cultivars and relationship to nitrogen supply"],"dc:type":["text"],"thesis:degree_discipline":["Horticulture"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:12Z"}