{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/21203"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/21203","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Effect of airflow and carbon dioxide on growth, yield, and gas exchange of lettuce","abstract":"Romaine lettuce (Lactuca sativa var. longifolia L.) was grown hydroponically inside a walk-in growth chamber (Conviron, PGW36) with two levels of airflow (0.36 and 2.50 m$\\rm\\cdot s\\sp{-1})$ at different atmospheric CO$\\sb2$ concentrations (350 and 700 $\\rm\\mu mol\\cdot mol\\sp{-1}).$ A combination of metal-halide and high-pressure sodium lamps was used to provide 30 mol$\\rm\\cdot m\\sp{-2}$ photosynthetic photon flux (PPF) per day with a 12-hour photoperiod at the rate of 660 $\\rm\\mu mol\\cdot m\\sp{-2}\\cdot s\\sp{-1}.$ Air temperature was maintained at 22$\\sp\\circ$C and relative humidity at 70% for both day and night. Nutrient solution pH was kept at 5.7 with nitrate as the sole nitrogen source. Growth analysis was carried out at 3-day intervals and gas exchange rate of both single-leaf and whole-plant was measured with a modified portable photosynthesis system (LI-COR, LI-6200 PPS). A microcomputer-based data acquisition and process control system was developed to maintain CO$\\sb2$ concentration and monitor environmental condition in each of the four runs of this experiment.","abstract_html":"Romaine lettuce (Lactuca sativa var. longifolia L.) was grown hydroponically inside a walk-in growth chamber (Conviron, PGW36) with two levels of airflow (0.36 and 2.50 m$\\rm\\cdot s\\sp{-1})$ at different atmospheric CO$\\sb2$ concentrations (350 and 700 <span class=\"etd-inline-math\">\\rm&mu; mol\\cdot mol\\sp{-1}).</span> A combination of metal-halide and high-pressure sodium lamps was used to provide 30 mol$\\rm\\cdot m\\sp{-2}$ photosynthetic photon flux (PPF) per day with a 12-hour photoperiod at the rate of 660 <span class=\"etd-inline-math\">\\rm&mu; mol\\cdot m\\sp{-2}\\cdot s\\sp{-1}.</span> Air temperature was maintained at 22$\\sp\\circ$C and relative humidity at 70% for both day and night. Nutrient solution pH was kept at 5.7 with nitrate as the sole nitrogen source. Growth analysis was carried out at 3-day intervals and gas exchange rate of both single-leaf and whole-plant was measured with a modified portable photosynthesis system (LI-COR, LI-6200 PPS). A microcomputer-based data acquisition and process control system was developed to maintain CO$\\sb2$ concentration and monitor environmental condition in each of the four runs of this experiment.","abstract_has_math":true,"creators":["Chen, Guang-Yau Stanley"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Crop Sciences","degree_department":null,"school":null,"contributors":["Spomer, L. Art"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:01:33Z","date_published":"2011-05-07T13:01:33Z","updated_at":"2026-07-22T22:25:17Z","subjects":["Agriculture, Agronomy","Biology, Plant Physiology"],"languages":["eng"],"rights":["Copyright 1996 Chen, Guang-Yau Stanley"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["9780591471984","AAI9737070","(UMI)AAI9737070"],"render_values":[{"text":"9780591471984","href":null,"code":true},{"text":"AAI9737070","href":null,"code":true},{"text":"(UMI)AAI9737070","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/21203","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Spomer, L. 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Nutrient solution pH was kept at 5.7 with nitrate as the sole nitrogen source. Growth analysis was carried out at 3-day intervals and gas exchange rate of both single-leaf and whole-plant was measured with a modified portable photosynthesis system (LI-COR, LI-6200 PPS). A microcomputer-based data acquisition and process control system was developed to maintain CO$\\sb2$ concentration and monitor environmental condition in each of the four runs of this experiment.","Results from this study indicated that CO$\\sb2$-enhancement can greatly increase the growth and yield of lettuce by increasing RGR shortly (1.3 days) after the treatment was applied. It created bigger plants while it kept them at the same physiological age with equal leaf number per plant as those grown under low CO$\\sb2$ environment. In contrast, higher airflow decreased lettuce yields by producing smaller plants with fewer leaves per plant than under lower airflow. The delay of growth and development caused by higher airflow was estimated to be 1.3 days, while RGR remained the same throughout the rest of growth.","The results of this study confirm that airflow is an important environmental factor, which should be controlled or characterized in every experiment. There should exist an optimal range of airflow for plants growing under unique environments. In order to promote the maximum crop growth and yield under a particular controlled environment, the timing and duration of CO$\\sb2$-enrichment and control of airflow need to be considered.","Made available in DSpace on 2011-05-07T13:01:33Z (GMT). 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Art"],"dc:creator":["Chen, Guang-Yau Stanley"],"dc:date":["2011-05-07T13:01:33Z","10000-01-01","1996"],"dc:description":["Romaine lettuce (Lactuca sativa var. longifolia L.) was grown hydroponically inside a walk-in growth chamber (Conviron, PGW36) with two levels of airflow (0.36 and 2.50 m$\\rm\\cdot s\\sp{-1})$ at different atmospheric CO$\\sb2$ concentrations (350 and 700 $\\rm\\mu mol\\cdot mol\\sp{-1}).$ A combination of metal-halide and high-pressure sodium lamps was used to provide 30 mol$\\rm\\cdot m\\sp{-2}$ photosynthetic photon flux (PPF) per day with a 12-hour photoperiod at the rate of 660 $\\rm\\mu mol\\cdot m\\sp{-2}\\cdot s\\sp{-1}.$ Air temperature was maintained at 22$\\sp\\circ$C and relative humidity at 70% for both day and night. Nutrient solution pH was kept at 5.7 with nitrate as the sole nitrogen source. Growth analysis was carried out at 3-day intervals and gas exchange rate of both single-leaf and whole-plant was measured with a modified portable photosynthesis system (LI-COR, LI-6200 PPS). A microcomputer-based data acquisition and process control system was developed to maintain CO$\\sb2$ concentration and monitor environmental condition in each of the four runs of this experiment.","Results from this study indicated that CO$\\sb2$-enhancement can greatly increase the growth and yield of lettuce by increasing RGR shortly (1.3 days) after the treatment was applied. It created bigger plants while it kept them at the same physiological age with equal leaf number per plant as those grown under low CO$\\sb2$ environment. In contrast, higher airflow decreased lettuce yields by producing smaller plants with fewer leaves per plant than under lower airflow. The delay of growth and development caused by higher airflow was estimated to be 1.3 days, while RGR remained the same throughout the rest of growth.","The results of this study confirm that airflow is an important environmental factor, which should be controlled or characterized in every experiment. There should exist an optimal range of airflow for plants growing under unique environments. In order to promote the maximum crop growth and yield under a particular controlled environment, the timing and duration of CO$\\sb2$-enrichment and control of airflow need to be considered.","Made available in DSpace on 2011-05-07T13:01:33Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9737070.pdf: 3096431 bytes, checksum: 01bc2159af9d7c995c0a99d57ee87f9f (MD5) Previous issue date: 1996","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:49:11Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:22:21-05:00 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":["9780591471984","AAI9737070","(UMI)AAI9737070","http://hdl.handle.net/2142/21203"],"dc:language":["eng"],"dc:rights":["Copyright 1996 Chen, Guang-Yau Stanley"],"dc:subject":["Agriculture, Agronomy","Biology, Plant Physiology"],"dc:title":["Effect of airflow and carbon dioxide on growth, yield, and gas exchange of lettuce"],"dc:type":["text"],"thesis:degree_discipline":["Crop Sciences"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:17Z"}