Influence of artificial shade on water stress of containerized ponderosa pine seedlings

1977 ◽  
Vol 7 (3) ◽  
pp. 537-540 ◽  
Author(s):  
Bruce A. Buchanan ◽  
Michael F. Davault ◽  
James T. Fisher
Keyword(s):  
New Mexico ◽  
Water Stress ◽  
Ponderosa Pine ◽  
Relative Water Content ◽  
Pressure Potential ◽  
Xylem Pressure ◽  
Sacramento Mountains ◽  
Pine Seedlings ◽  
Xylem Pressure Potential ◽  
Relative Water

Artificially shaded and unshaded containerized Pinusponderosa Laws, seedlings were planted in the Sacramento Mountains of southern New Mexico on July 29, 1975. Xylem pressure potential (Pstem) and relative water content (RWC) were measured four times per day from August 1 to 16, 1975. Shading had little effect on RWC but significantly increased Pstem; midafternoon (1530 hours, MDST) increase averaged 2 bars (1 bar = 105 Pa). During the study RWC ranged from 86 to 94% and Pstem ranged from −4 to −10 bars. At the end of September no mortality had occurred in either treatment.

Effect of Biostimulants on Drought Tolerance of Ornamental Annuals

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 539d-539
Author(s):  
S.A. Geer ◽  
T.J. Smalley ◽  
M.W. Rieger
Keyword(s):  
Drought Tolerance ◽  
Relative Water Content ◽  
Dry Weight ◽  
New Haven ◽  
Pressure Potential ◽  
Xylem Pressure ◽  
Shoot Dry Weight ◽  
Salvia Splendens ◽  
Xylem Pressure Potential ◽  
Relative Water

This study determined the effect of the granular humate Earthgreen (Menefee Mining Corp., Dallas) and the biostimulant ROOTS2™ (LISA Products Corp., New Haven, Conn.) on drought tolerance of the ornamental annuals Impatiens wallerana `Accent White' and Salvia splendens `Red Hot Sally'. Earthgreen was incorporated into the soil and ROOTS2™ applied as a root drench at transplanting and 30 days after transplanting, Transplants were established in greenhouse beds under irrigated conditions for 8 weeks, then subjected to a five week drought. Data indicates rates of 43.9 and 87.9 g·m–2 of Earthgreen or 300 ml of 1% or 2% ROOTS2™ per plant had no significant effect on Salvia shoot dry weight or chlorophyll content of Salvia or Impatiens at the end of the 8-week establishment period. However, Salvia flower dry weight was significantly increased with the higher rate of Earthgreen. During the 5-week drought, Earthgreen or ROOTS2™ did not significantly affect xylem pressure potential of Salvia or relative water content of Impatiens. After the 5-week drought no significant effect of either product on shoot dry weight of Salvia or Impatiens or flower dry weight of Salvia was observed.

Effects of drying soils on survival of young Piceaglauca seedlings

1982 ◽  
Vol 12 (4) ◽  
pp. 1006-1009 ◽  
Author(s):  
E. C. Tear ◽  
K. O. Higginbotham ◽  
J. M. Mayo
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Water Loss ◽  
Growing Season ◽  
Combined Effects ◽  
Pressure Potential ◽  
Greenhouse Soil ◽  
Soil Mixture ◽  
Xylem Pressure ◽  
Xylem Pressure Potential

Drought stress is often suggested as a factor preventing successful field establishment of seedlings of white spruce (Piceaglauca (Moench) Voss) during their first growing season. In this study the combined effects of water stress and seedbed type on 1- and 3-month-old seedlings were examined. Shoot xylem pressure potential decreased to −1.5 MPa in seedlings grown in a greenhouse soil mixture in 9.5 days but took 18.5 days to reach this level in peat. Mortality reached 100% for 1-month-old seedlings grown in greenhouse mix 11 days after watering ceased, while it took 23 days to reach this level in peat. Shoot xylem pressure potentials can be used to predict mortality potential on the two seedbed types. Three-month-old seedlings on either seedbed survived for at least 31 days without watering, indicating development of capability for control of water loss with time.

Measurement of water stress in subalpine trees: effects of temporary tissue storage methods and needle age

1982 ◽  
Vol 12 (4) ◽  
pp. 969-972 ◽  
Author(s):  
Merrill R. Kaufmann ◽  
Gary L. Thor
Keyword(s):  
Water Stress ◽  
Conifer Species ◽  
Pressure Potential ◽  
Tissue Storage ◽  
Storage Tissue ◽  
Tissue Samples ◽  
Needle Age ◽  
Xylem Pressure ◽  
Xylem Pressure Potential ◽  
Storage Methods

Water stress of subalpine conifer species may be measured with the pressure chamber after several hours of tissue storage. Tissue samples stored in cool, humid vials exhibited very little change in xylem pressure potential over a 4-h period. However, xylem pressure potential declined steadily when a source of water vapor was not available. Xylem pressure potentials of current-year and 1-year-old needles of lodgepole pine (Pinuscontorta var. latifolia Engelm.) were slightly lower than those of older needles.

The water relations of the field bean crop

1976 ◽  
Vol 273 (927) ◽  
pp. 581-591 ◽  
Keyword(s):  
Water Stress ◽  
Water Content ◽  
Water Relations ◽  
Relative Water Content ◽  
Field Bean ◽  
Pressure Potential ◽  
Relative Water ◽  
Absolute Growth ◽  
Bean Crop ◽  
Field Beans

The water relations of crops of field beans, Vicia faba , are analysed. Three parameters (the solute potential at zero turgor, the relative water content at zero turgor and the slope of the line relating pressure potential to relative water content) are used. All three decrease with water stress. Measurements of leaf area show that water stress decreases the absolute growth rate but does not affect the duration of growth very much.

Critical Period of Weed Interference in Transplanted Tomatoes (Lycopersicon esculentum): Growth Analysis

Weed Science ◽  
1983 ◽  
Vol 31 (4) ◽  
pp. 476-481 ◽  
Author(s):  
Susan E. Weaver ◽  
Chin S. Tan
Keyword(s):  
Lycopersicon Esculentum ◽  
Critical Period ◽  
Growth Analysis ◽  
Canopy Temperature ◽  
Dry Weight ◽  
Pressure Potential ◽  
Xylem Pressure ◽  
Fruit Number ◽  
Weed Interference ◽  
Xylem Pressure Potential

The critical period of weed interference in transplanted tomatoes (Lycopersicon esculentumMill. 'Springset’) was from 28 to 35 days after transplanting. A single weeding during this period was sufficient to prevent yield reductions. A growth analysis revealed that significant differences in plant dry weight and fruit number between tomatoes from weed-free and weed-infested plots were not apparent until 56 to 70 days after transplanting. The shorter the initial weed-free period, or the longer weeds were allowed to remain in the plots before removal, the earlier reductions in tomato dry weight and fruit number appeared. Weed interference was due primarily to shading rather than water stress. Tomatoes from weed-infested plots had significantly lower stomatal conductances than those from weed-free plots, but did not differ in xylem-pressure potential or in canopy temperature. If tomatoes were kept weed-free for more than 28 days, or when weeds were present for less than 28 days after transplanting, stomatal conductances were not significantly reduced.

Comparative Studies in Selected Species of Eucalyptus Used in Rehabilitation of the Northern Jarrah Forest, Western Australia. I. Patterns of Xylem Pressure Potential and Diffusive Resistance of Leaves

1984 ◽  
Vol 32 (4) ◽  
pp. 367 ◽  
Author(s):  
IJ Colquhoun ◽  
RW Ridge ◽  
DT Bell ◽  
WA Loneragan ◽  
J Kuo
Keyword(s):  
Western Australia ◽  
Water Loss ◽  
Seasonal Patterns ◽  
Pressure Potential ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Xylem Pressure ◽  
Diffusive Resistance ◽  
Xylem Pressure Potential ◽  
The Impact

Land use which reduces tree canopy density and the impact of Phytophthora cinnamomi are believed to be altering the hydrological balance of parts of the northern jarrah forest, Western Australia. In the drier eastern zones of the forest, replacement plant communities must maintain the soil-salt-water balance to prevent significant increases in salinization of streams in water supply catchments. Daily and seasonal patterns of the diffusive resistance of leaves and xylem pressure potential were determined for the major natural dominant of the region, Eucalyptus marginata, and five other species of Eucalyptus used in rehabilitation. Three types of daily and seasonal patterns were observed. E. marginata and E. calophylla exhibited little stomatal control of water loss, and leaf resistances remained low throughout the study period (type 1). E. maculata, E. resinifera and E. saligna exhibited marked stomatal regulation during summer days when xylem pressure potentials fell below -2.O MPa (type 2). E. wandoo (type 3) also controlled water loss but developed xylem pressure potentials far lower than all other species tested (<-3.0 MPa). Although none of the species tested replicated the summer stomatal resistance and xylem pressure potential patterns of E. marginata, it is suggested that total annual water use should be examined before selecting the most appropriate species to rehabilitate disturbed sites in the eastern zones of the northern jarrah forest region.

scholarly journals In vitro screening of rice genotypes using polyethylene glycol under drought stress

2016 ◽  
Vol 27 (2) ◽  
pp. 128-135 ◽  
Author(s):  
J Akte ◽  
S Yasmin ◽  
MJH Bhuiyan ◽  
F Khatun ◽  
J Roy ◽  
...  
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Water Content ◽  
Relative Water Content ◽  
Dry Weight ◽  
Proline Accumulation ◽  
Shoot Length ◽  
Fresh Weight ◽  
Relative Water

Five rice varieties viz. Binadhan-4, Binadhan-5, Binadhan-6, Binadhan-10 and Iratom-24 were evaluated in vitro under different water stress conditions. Several parameters such as germination percentage, shoot length, root length, shoot-root ratio, fresh weight, dry weight, turgid weight, relative water content and proline accumulation were studied. Drought condition was created by MS medium supplemented with five treatments of PEG, with a control such as 0%, 1%, 2%, 3% and 4% of PEG. The highest germination (100%) was found in the variety Binadhan-10 under low water stress conditions induced by 1% PEG. Similarly, the highest percentage of germination was found in all varieties under control condition (0% PEG). The lowest percentage of germination was obtained in the variety Iratom-24. But under severe stress (4% PEG), the highest percentage of germination was found only in the variety Binadhan-10. Moreover, the variety Binadhan-10 was found to be the best at 4% PEG for shoot length, root length, shoot-root ratio, relative water content and also the best at 1% PEG for fresh weight, dry weight, turgid weight. Water stress decreased relative water content and increased proline accumulation in rice. The highest relative water content was recorded in the variety Binadhan-10 and the lowest value recorded in the variety Binadhan-5. The highest proline content was obtained from the binadhan-6 at the highest treatment (4% PEG). Binadhan-10 showed the best performance almost in all the parameters under drought stress because of its own nature of tolerancy.Progressive Agriculture 27 (2): 128-135, 2016

Stomatal control and the development of water deficit in Engelmann spruce seedlings during drought

1979 ◽  
Vol 9 (3) ◽  
pp. 297-304 ◽  
Author(s):  
Merrill R. Kaufmann
Keyword(s):  
Flux Density ◽  
Stomatal Closure ◽  
Absolute Humidity ◽  
Pressure Potential ◽  
Evaporative Demand ◽  
Xylem Pressure ◽  
Full Sunlight ◽  
Engelmann Spruce ◽  
Xylem Pressure Potential ◽  
The Relationship

The effects of soil drying on water relations of Engelmann spruce (Piceaengelmannii Engelm.) were studied by withholding water from 4-year-old potted seedlings in full sunlight and under a shade screen transmitting 55–60% light. During a period of 2 months, xylem pressure potential, water vapor conductance, and transpirational flux density gradually declined compared with well watered controls, with drying being more rapid in full sunlight. As drying progressed, xylem pressure potential at 0 transpiration (predawn potential) decreased and the slope of the relationship between xylem pressure potential and transpirational flux density became more negative. Hysteresis in the relationship occurred when predawn xylem pressure potential was −6 bars (1 bar = 105 Pa) or lower. Needle conductance during daylight hours decreased as the absolute humidity difference from leaf to air increased but conductances were lower in September than in August for given humidity differences. Xylem pressure potentials between −15 and −19 bars had no clear effect on conductance in August but apparently caused significant stomatal closure in September. Because of humidity-induced stomatal closure, evaporative demand had little effect on transpirational flux density over a broad range of humidity gradient. Thus increased leaf-to-air vapor gradients for transpiration are not always accompanied by increased transpiration.

scholarly journals Modifications in vapor diffusion resistence of leaves and water relations in barbados cherry plants under water stress

2001 ◽  
Vol 13 (1) ◽  
pp. 75-87 ◽  
Author(s):  
REJANE J. MANSUR C. NOGUEIRA ◽  
JOSÉ ANTÔNIO P. V. DE MORAES ◽  
HÉLIO ALMEIDA BURITY ◽  
EGÍDIO BEZERRA NETO
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Content ◽  
Relative Water Content ◽  
Leaf Temperature ◽  
Diffusive Resistance ◽  
Severe Water Stress ◽  
Relative Water ◽  
Proline Concentration ◽  
Prolonged Stress

Young sexually and assexually propagated Barbados cherry plants were submitted to water deficit (20 days without irrigation). During this period the accumulation of proline, water potential of branches, osmotic potential, the relative water content of leaves, the leaf diffusive resistance, the transpiration rate and leaf temperature in the cuvette were determined. In addition, photosynthetically active radiation (PAR) and vapor pressure deficit (VPD) were measured in the porometer cuvette. The concentration of proline for both types of plants began to increase on the fifth day without watering, and reached 38.1 times the concentration in the control plants grown from seeds and 26.4 times the concentration in grafted plants on the tenth day without watering. The lowest levels of leaf water potential in the plants suffering from severe water stress varied from -4.5 to -5.7 MPa, the lowest values being observed in the sexually propagated plants. These plants also showed the highest values for transpiration (0.9 mmol.m-2.s-1) and proline concentration (20.42 mg.g-1 DM), the lowest for relative water content of the leaves (38.4%) and diffusive resistance (940 s.m-1) at the end of the experiment. The Barbados cherry plants developed strategies for surviving drought, with differences between various characteristics, resulting from prolonged stress, which significantly influenced the parameters evaluated, with the exception of leaf temperature.

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