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Adaxial and Abaxial Stomatal Resistance of Cotton in the Field 1
Author(s) -
Sharpe Peter J. H.
Publication year - 1973
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1973.00021962006500040014x
Subject(s) - lysimeter , transpiration , transpiration stream , resistance (ecology) , drought resistance , gossypium hirsutum , fiber crop , water content , agronomy , water stress , environmental science , horticulture , biology , botany , soil water , soil science , photosynthesis , geotechnical engineering , engineering
An experiment was conducted near Sydney, Australia to determine the adaxial and abaxial stomatal responses of cotton ( Gossypium hirsutum L.) to environmental factors under noncycling field conditions. Cotton plants were grown in small lysimeter pans and transpiration was measured by strain guage lysimeters. Leaf temperature, ambient temperature and other micrometeorological parameters were monitored continuously, Stomatal resistances were regularly measured for both surfaces with a diffusion resistance porometer developed by the author. It was found that under field conditions, the adaxial and abaxial stomata differ in their response to light, water stress, and ambient temperature. Under most conditions, including darkness and. drought, the adaxial surface was considerably higher in resistance than the abaxial surface. However, the differences in resistance between the two surfaces disappeared under a combination of high light and temperature conditions. High transpiration rates and low leaf resistance were associated with high ambient temperatures. With sufficient soil moisture there was no evidence of midday stomatal closure even under severe light and temperature regimes. It was found that sampling the resistance of one surface alone (particularly the adaxial) did not give an accurate estimate of the overall leaf resistance. In addition, it was also found that similar .resistances on both surfaces under any one set of environmental conditions does not necessarily imply that this will be so under all conditions.