Micrometeorology and physiology of sugarcane crop during water stress
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Date
2001-11
Authors
Koonjah, S. S.
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Free State
Abstract
Water stress is the single most important factor limiting yield
in plants. The effects of water stress on the micrometeorology
and physiology of sugarcane were investigated using the
rainshelter facilities provided at the South African Sugar
Association Experiment Station, Mount Edgecombe.
Sugarcane variety NCo37 6 was stressed at the age of seven
months during the first ratoon crop. Plant extension rate (PER)
together with microclimatic measurements including radiation
interception, and leaf and canopy temperature were measured
continuously. Photosynthesis and leaf water potential were also
measured on a daily basis together with the volumetric soil
water content.
Among the yield-determining processes, plant extension rate was
the first to be significantly affected 10 days after onset of
water stress. The leaf water potential (ΨL measured at this
stage was -0.7 MPa. Leaf area index and radiation interception
were the next processes to be affected. A significant decrease
in photosynthetic rate occurred 19 days after onset of water
stress when the ΨLwas at -1.0 MPa. More than 50% reduction in
radiation use efficiency occurred 24 days after imposing water
stress and the ΨLmeasured at this stage was -1.5 MPa.
Recovery from the first stress as far as plant extension rate
and photosynthesis were concerned, occurred within 3 to 4 days
after irrigation was resumed. When the same sugarcane plants
were stressed for a second time, it took fewer days for plant
extension rate and photosynthesis to be severely affected as
compared to the stress imposed during the first time.
Description
Keywords
Sugarcane -- Effect of drought on, Sugarcane -- Water requirements, Sugarcane -- Climatic factors, Dissertation (M.Sc.Agric. (Agrometeorology))--University of the Free State, 2002