Water availability is a critical limiting element in semi-arid ecosystem productivity and presents particular challenges in Sahelian countries such as Senegal. The landscapes are characterized by the presence of two common semi-arid shrubs (Piliostigma reticulatum and Guiera senegalensis), both of which may be important hydraulic regulators in these water-limited ecosystems....
Laboratory experiments were used to investigate the mechanism
of plant response to water stress by determining the sensitivity of leaf
elongation, photosynthesis and transpiration in young corn plants to a
decrease in leaf water potential.
In initial experiments, 9 day old corn plants were grown at soil
water potentials of...
An adequate stand at the optimum time is an important factor
affecting potential yield and soil erosion control. However, obtaining
adequate stands of fall planted winter wheat in the dryland areas of the
Pacific Northwest is often complicated by marginal seed zone soil
moisture. The purpose of this laboratory study...
A series of experiments was designed to investigate differential
flood-tolerance and the phenomenon of flood-induced stomatal closure
of several fruit tree species. The first two experiments were conducted
with potted plants submerged outdoors 5-10 cm above the soil line.
Plant morphology, growth, leaf conductance (cL), and soil oxygen diffusion
rate...
The use of chemicals such as the triazines (especially atrazine) and mixtures of the triazines and 2,4-D or 2,4,5-T has become almost standard practice in some parts of the world for selectively controlling grasses and other herbaceous weeds to conserve moisture for and/or prevent the smothering of newly-planted conifers. In...
The major objectives of this study were an
evaluation of the Meteorological Office Rainfall and
Evaporation Calculation System (MORECS) evapotranspiration
(ET) model using the Penman-Monteith equation and
comparison of the MORECS and measured surface resistance.
Meteorological, soil and plant parameters were measured in
an alfalfa field over two growing seasons....
Farmlands, grasslands, and savannas in semi-arid sub-Sahelian Africa have the potential to store
carbon (C) in soil. There is a great need to manage ecosystems to increase C storage in semipermanent
soil pools. This will improve soil quality, impede desertification and by reducing
atmospheric CO₂ levels, will slow climate change....
Published May 1931. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Coffee trees growing in the Kona district of Hawaii
were treated with different concentrations of either BA,
GA3, or Promalin, and pruned at the time of flowering. No
significant differences in the flowering and fruit ripening
pattern were found. High concentrations (100 mg/1) of
growth regulators decreased fruit fresh weight....
This thesis research examines the effects of film-forming antidesiccants applied to dormant pondexosa pine (Pinus ponderosa Dougl.) seedlings after being lifted and to actively growing seedlings. The basic proposition was that antidesiccants would have a positive effect on reducing water loss in ponderosa pine seedlings. In order to evaluate the...
The relationships among total water potential (psi), osmotic potential ([pi]), pressure potential (P), and relative water content (R*) were determined during four consecutive soil drying cycles for shoots of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings. In each cycle, seedlings were sampled for pressure-volume determinations as soil water was depleted gradually...
The principles of continuum mechanics provide a consistent
framework for the derivation of mathematical statements describing
transport of water and solute, and growth in plant tissue. These
derivations are based upon the explicit consideration of the tissue as
a mathematical continuum composed of a cell wall matrix, water, and
solute...
Evaluation and sensitivity analysis of a soil-water---
atmosphere-plant simulation model, SWATRE, developed by
Feddes et al (1978) in The Netherlands was conducted.
The evaluation was performed with the observed data
obtained by Cuenca (1978) for three different irrigation
levels in UC82 variety tomato fields in Davis,
California. SWATHE requires about...