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Effects of incandescent radiation on photosynthesis, growth rate and yield of 'Waldmann's Green' leaf lettuceEffects of different ratios of incandescent (ln) to fluorescent (Fl) radiation were tested on growth of 'Waldmann's Green' leaf lettuce in a controlled environment. After 4 days of treatment, dry weight, leaf area, relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR) and photosynthetic rate (Pn) were greater for plants grown at 84 rather than 16 percent of total irradiance (82 W/sq m) from ln lamps. Although leaf dry weight and area were 12-17 percent greater at 84 percent ln after the first 8 days of treatment, there were no differences in RGR or Pn between treatments during the last 4 days. If 84 percent ln was compared with 50 percent ln, all cumulative growth parameters, RGR, NAR and Pn were greater for 84 percent ln during the first 4 days of treatment. However, during the second 4 days, RGR was greater for the 50 percent ln treatment, resulting in no net difference in leaf dry weight or area between treatments. Shifting from 84 to 50 percent ln radiation between the first and second 4 days of treatment increased plant dry weight, leaf area, RGR and NAR relative to those under 84 percent ln for 8 days continuously.
Document ID
19930062471
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Knight, Sharon L.
(NASA Ames Research Center Moffett Field, CA, United States)
Mitchell, Cary A.
(Purdue Univ. West Lafayette, IN, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1988
Publication Information
Publication: Scientia Horticulturae
ISSN: 0304-4238
Subject Category
Life Sciences (General)
Accession Number
93A46468
Funding Number(s)
CONTRACT_GRANT: NCC2-100
Distribution Limits
Public
Copyright
Other

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