© 1987 Oxford University Press
RESEARCH-ARTICLE |
Saturation Deficit, Canopy Formation and Function in Sorghum bicolor (L.)
Department of Physiology and Environmental Science, University of Nottingham School of Agriculture Sutton Bonington, Loughborough, Leics. LE12 5RD, U.K.
2 To whom all correspondence should be addressed.
Correspondence to: Department of Physiology and Environmental Science, University of Nottingham School of Agriculture, Sutton Bonington, Loughborough, Leics. LE12 5RD, U.K.
Hamdi, Q. A., Harris, D. and Clark, J. A. 1987. Saturation deficit, canopy formation and function in Sorghum bicolor (L.).J. exp. Bot. 38: 12721283.
Stands of two sorghum genotypes, SPV 354 and MK. 35-1, were grown in controlled-environment glasshouses at three levels of saturation vapour pressure deficit (SD), at the same temperature and with unrestricted soil moisture. Vegetative growth was monitored by growth analysis and non-destructive measurements were made of leaf appearance, leaf extension and final size, and fractional light interception. Rates of leaf appearance were reduced at high SD in both genotypes, although this may have been an artefact of the method of measurement, and MK 35-1 produced leaves more slowly than SPV 354. Leaf extension was also slowed as SD increased and, since the duration of extension for individual leaves of a given age remained constant, resulted in smaller leaf area indices (L) in dry air than in humid air. The cumulative interception of radiation and the dry matter/radiation quotient (e) both decreased as SD increased.
Key words: Sorghum, saturation deficit, canopy formation