, chlorophyll fluorescence (Fv:Fm ratio), and predawn leaf water potential did not indicate the presence of stress in field-grown Passiflora ligularis during standard growing conditions. Water stress affects plant growth because cell growth is one of the most
Alexandra García-Castro, Astrid Volder, Hermann Restrepo-Diaz, Terri W. Starman, and Leonardo Lombardini
Krista Shellie and D. Michael Glenn
higher transpiration in apple under a temperate climate. An objective of this research was to determine whether foliar particle film increased leaf water potential and/or g S in field-grown wine grapes under varying levels of vine water stress. The
Paongpetch Phimchan, Suchila Techawongstien, Saksit Chanthai, and Paul W. Bosland
( Techawongstien et al., 1992 ). When severe wilting persisted overnight, the plants in the drought stress treatment were re-watered at the rate of the control plants. The mean values of leaf water potential, relative water content, plant height, stem diameter
Nisa Leksungnoen, Paul G. Johnson, and Roger K. Kjelgren
. Measurements. Predawn leaf water potential measurements were made twice a week in 2007 and once a week in 2008 using a pressure chamber (Model 3005HGPL; Soil, Moisture Equipment Corp, Santa Barbara, CA). At predawn, five stems of each species in each subplot
R. Ceulemans, I. Impens, and R. Gabriels
Leaf water potential, leaf water vapour diffusion resistance and transpiration of azalea (Rhododendron simsii Planch, sp. cvs. Hellmut Vogel and Reinhold Ambrosius) were measured over a 7-day drying period. Both cultivars had an effective and active regulation of their water balance. Recovery after severe water stress was rapid. Differences in water regulation with regard to stomatal dimensions and densities were found in both cultivars. Difference in behaviour to water stress was greatly dependent on root/shoot ratio.
J. J. Allen, T. A. Nell, J. N. Joiner, and L. G. Albrigo
There were generally no decreases in water potential when leaves of chrysanthemum (Chrysanthemum morifolium Ramat.) were stored in plastic bags for 1-5 hours, individually or together, provided a moist towel was included. Decreases in water potential occurred after 1 and 3 hours in leaves stored individually or together without a moist towel. Maximum stress was observed in the third negative at 0600 hours with values increasing to a maximum of −8.1 bars at 1400 hours.
John C. Pair and Steven M. Still
Ilex X meserveae S. Y. Hu cvs. Blue Angel, Blue Maid, Blue Princess (pistillate) and Blue Prince (staminate) were planted around specially designed cross-shaped structures to determine tolerance to summer and winter stresses as affected by sun, shade, and wind patterns. Most plant damage occurred in the summer on the S and SW exposures where plant canopy and soil temperatures reached 43° and 48°C, respectively. All cultivars survived −23° in winter, but ‘Blue Angel’ was damaged. ‘Blue Princess’ was the hardiest and most fruitful cultivar. Shoot growth was greatest on ‘Blue Prince’ and ‘Blue Maid’. Plants performed best on the N, NE, and NW exposures, where summer temperatures were relatively cool and foliage temperature fluctuation were reduced in winter.
C. D. Stanley, B. K. Harbaugh, and J. F. Price
Leaf water potential (LWP) data for cut-flower chrysanthemums (Crysanthemum morifolium Ramat.) collected from 5 different irrigation rate treatments throughout the growing season were compared to the final plant characteristics and yield in order to evaluate the usefulness of LWP for estimating water stress effects on ultimate yield. Significant treatment differences for LWP response measured during high evaporative demand periods were similar to treatment differences for yields and final plant characteristics. Treatment differences for LWP response measured during low evaporative demand periods were not significant and did not reflect the significant treatment differences for yields and final plant characteristics. Results indicate that LWP measurements vary with changes in atmospheric conditions, such as cloud cover, and are difficult to interpret relative to water stress effects on final plant characteristics. Plant growth parameters, such as height or growth rate, when monitored during the season, were found to be more adequate indicators of stress effects on final yield.
Terence L. Robinson and Bruce H. Barritt
Abbreviations: ABA, abscisic acid; c, t-ABA, cis, trans-abscisic acid; LPI, leaf plastochron index; PI, plastochron index age; ψ P , leaf turgor pressure; ψ S , leaf osmotic potential; ψ W , leaf water potential; t , t-ABA, trans, trans
Jianping P. Wang, Suleiman S. Bughrara, and C. Jerry Nelson
( Festuca mairei ) compared with three tall fescue ( F. arundinacea Schreb.) cultivars: Kentucky 31, Falcon II, and Barolex. Objectives of this study were to compare leaf elongation, leaf water content, leaf water potential, root biomass, and root length