New Zealand Journal of Crop and Horticultural Science abstracts
Variations in water availability and temperature in the root environment
during root volume restriction studies
M. B. HURLEY
J. S. ROWARTH
M. C. T. TROUGHT
Soil, Plant and Ecological Sciences Division
P. O. Box 84
Lincoln University
New Zealand
M. F. BARNES
Animal and Food Sciences Division
P. O. Box 84
Lincoln University
New Zealand
R. N. ROWE
Soil, Plant and Ecological Sciences Division
P. O. Box 84
Lincoln University
New Zealand
Abstract Variations were investigated in matric potential
([[Psi]]ms) and temperature in the root environment of tomato plants
(
Lycopersicon esculentum Mill. `Red Dwarf') grown over a range (200,
400, or 800 cm
3) of rooting volumes (RV). Under media-based
growing conditions, [[Psi]]ms
and temperature varied inversely with
RV. The root environment in the smallest RV had a 2-fold decrease in [[Psi]]ms
to -14 kPa, a greater rate of decrease in [[Psi]]ms and a lower overall
[[Psi]]ms magnitude of -30 kPa (compared with -12 kPa in the largest RV). There
were large diurnal temperature fluctuations (range = 12deg.C) and the root
environment in the smallest RV was consistently 3deg.C higher with a mean of
25.4deg.C, compared with a mean of 22.3deg.C in the largest RV. Enclosing the
pots within a modified hydroponic system, in conjunction with a very frequent
watering regime, eliminated differences in [[Psi]]ms and reduced differences
in
media temperature between different RVs. The physiological basis of the
dwarfing response previously associated with RVR may have been inadvertently
confounded with variations in media [[Psi]]ms and media temperature.
Keywords rooting volume (RV); root volume restriction (RVR);
media matric potential; media temperature; Lycopersicon esculentum
H97-67
Received 10 December 1997; accepted 2 March 1998
PDF file of entire paper: medium quality (548K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
