Use of a Hydraulic Press for Estimation of Leaf Water Potential in Grain Sorghum 1

1986 ◽  
Vol 78 (4) ◽  
pp. 749-751 ◽  
Author(s):  
S. K. Hicks ◽  
R. J. Lascano ◽  
C. W. Wendt ◽  
A. B. Onken
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Grain Sorghum ◽  
Hydraulic Press ◽  
Leaf Water

Evaluation of the hydraulic press for measurement of leaf water potentials in cassava

1983 ◽  
Vol 101 (2) ◽  
pp. 407-410 ◽  
Author(s):  
J. A. Palta
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Hydraulic Press ◽  
Pressure Chamber ◽  
Leaf Water ◽  
Moisture Loss ◽  
Total Leaf Area ◽  
Water Potentials ◽  
Wide Range ◽  
Poor Relationship

SUMMARYIn the application of the Scholander pressure chamber technique to cassava water relations studies, the leaf water potential measured on central lobules was initially compared with that measured on entire leaves (including petiole). Measurements made using both a Campbell-Brewster hydraulic press and a pressure chamber of the leaf water potential in six different cassava clones were also compared. Although the central lobules showed a greater sensitivity to moisture loss after sampling than entire leaves, their leaf water potential was in close agreement with those measured on the entire leaves (r3 = 0·96). Therefore, for routine and field estimates in cassava, measurements made on the central lobules may be used to avoid the large reduction in total leaf area. The Campbell-Brewster hydraulic press satisfactorily estimated leaf water potential in M.Col. 1684 clone, which had the longest and narrowest lobules, but in other clones the leaf water potential was overestimated at high leaf potential (> -12·5) and underestimated at low water potentials (< -12·5). Over a wide range of leaf water potentials, a poor relationship between leaf water potentials estimated with hydraulic press and with the pressure chamber was observed for cassava because press estimates are influenced by lobule length and lobule width.

Differences between two grain sorghum genotypes in adaptation to drought stress. III. Physiological responses

1983 ◽  
Vol 34 (6) ◽  
pp. 637 ◽  
Author(s):  
GC Wright ◽  
RCG Smith ◽  
JM Morgan
Keyword(s):  
Root Growth ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Physiological Responses ◽  
Grain Sorghum ◽  
Leaf Water ◽  
Physiological Basis ◽  
Solute Accumulation ◽  
Sorghum Genotypes ◽  
Adaptation To Drought

A sorghum hybrid (E-57) giving a higher yield under rain-fed systems of production was studied to examine the physiological basis of this effect. A comparison was made with another hybrid (TX-671) with similar maturity. E-57 was able to maintain stomatal opening to a lower leaf water potential than TX-671 because of its greater capacity to osmoregulate. In E-57 osmotic potential declined due to active solute accumulation, thus maintaining turgor as leaf water potential declined to - 2.0 MPa. In contrast, TX- 671 could only maintain this adjustment to - 1.4 MPa. The differences in osmoregulation were associated with maintenance of leaf area, water extraction and possibly root growth by E-57. This indicated that osmoregulation enabled photosynthesis to continue and that a significant amount of the resultant assimilate may have been diverted to root growth.

Improvement of the water status and yield of field-grown grain sorghum (Sorghum bicolor) by inoculation withAzospirillum brasilense

1988 ◽  
Vol 110 (2) ◽  
pp. 271-277 ◽  
Author(s):  
S. Sarig ◽  
A. Blum ◽  
Y. Okon
Keyword(s):  
Soil Moisture ◽  
Stomatal Conductance ◽  
Grain Yield ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Dry Matter ◽  
Water Status ◽  
Grain Sorghum ◽  
Leaf Water ◽  
Dry Matter Accumulation

SummaryThe effect of inoculation withAzospirillum brasilenseon growth, water status and yield of dryland sorghum (cv. RS 610 and cv. H-226) growing on stored soil moisture was examined in three field experiments conducted during the years 1983–5.Plants were sampled at regular intervals, and the following characteristics were measured: dry-matter accumulation, leaf area, grain yield, percentage nitrogen and phosphorus in leaves, leaf water potential, canopy temperature, transpiration, stomatal conductance and soil water depletion.Inoculation led to an average increase of 19% in total stover dry-matter yield, as a result of higher rates of dry-matter accumulation during the early stages of growth.Azospirilluminoculation caused a 15–18% increase in grain yield in all three experiments. This increase was associated with a greater number of seeds per panicle.The water regime of sorghum plants was improved by inoculation, as seen in their higher leaf water potential, lower canopy temperatures and greater stomatal conductance and transpiration. Total extraction of soil moisture by inoculated plants was greater (by about 15%) and occurred from deeper soil layers, compared with non-inoculated controls.These findings indicate that inoculation withAzospirillumcan lead to yield increases in dryland grain sorghum, primarily through improved utilization of soil moisture.

scholarly journals Hydraulic Press Measurements of Leaf Water Potential in Groundnuts

1983 ◽  
Vol 19 (4) ◽  
pp. 287-291 ◽  
Author(s):  
G. Rajendrudu ◽  
M. Singh ◽  
J. H. Williams
Keyword(s):  
Regression Analysis ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Error Variance ◽  
Hydraulic Press ◽  
Pressure Chamber ◽  
Leaf Water ◽  
Dew Point ◽  
Functional Relations ◽  
The Press

SUMMARYThe hydraulic press was compared with the dew point psychrometer and the pressure chamber methods for measuring leaf water potential (Ψ) in groundnuts (Arachis hypogaea L.). For measurements on the same leaf, regression analysis revealed that the slopes did not differ significantly from unity. An analysis of functional relations between measurements made by the press and the dew point psychrometer or the press and the pressure chamber showed that the error variance of the press was similar to those of the two other methods. Therefore, we conclude that for groundnuts the performance of the press, the dew point psychrometer and the pressure chamber are similar.

Comparisons between Press and Pressure Chamber Techniques for Measuring Leaf Water Potential

1981 ◽  
Vol 17 (1) ◽  
pp. 75-84 ◽  
Author(s):  
T. M. Yegappan ◽  
B. J. Mainstone
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Elaeis Guineensis ◽  
Water Status ◽  
High Water ◽  
Hydraulic Press ◽  
Pressure Chamber ◽  
Leaf Water ◽  
Wide Range ◽  
The Press

SUMMARYA hydraulic press (the J-14) was compared with a Scholander pressure chamber to measure leaf water potential in Theobroma cacao, Gliricidia maculata, Cajanus cajan and Elaeis guineensis. Although the press satisfactorily estimated water status in soft, unhardened leaves of T. cacao, G. maculata and C. cajan at high water potential, it underestimated water status in hardened leaves of T. cacao. Satisfactory estimates were obtained at low water potential for hardened leaves of T. cacao but not for the others. There was a poor relation between readings of the two instruments for E. guineensis over a wide range of water potentials because press readings appeared to be influenced by leaf structure.

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