scholarly journals Vine water deficit : among the 3 applications of pressure chamber, stem water potential is the most sensitive indicator

OENO One ◽  
2000 ◽  
Vol 34 (4) ◽  
pp. 169
Author(s):  
Xavier Choné ◽  
Olivier Trégoat ◽  
Cornelis Van Leeuwen ◽  
Denis Dubourdieu

<p style="text-align: justify;">Vine water status is an important factor in grape quality. High tannin and anthocyanin content in red grape berries are related to moderate vine water deficits. Hence, a simple and sensitive indicator is required to determine vine water status and especially water constraint. Pressure chamber allows a quick and easy to practice determination of water status in the vineyard. Three applications of pressure chamber are known: predawn leaf water potential (ΨB), leaf water potential (ΨF) and stem water potential (ΨT). Only ΨB and ΨF are widely used on vines. In this survey ΨB, ΨF, ΨT and transpiration flow were measured on mature leaves to determine non-irrigated vine water status in field grown vines during the growing season. In California as well as in France, stem Ψ was the most discriminating indicator for both moderate and severe water deficits. In every plot surveyed ΨT was much better correlated to leaf transpiration than ΨF. Moreover, ΨT revealed nascent water deficit earlier than ΨB did. Among the three application of pressure chamber, ΨT was the only one to indicate short term water deficit after a rainfall. Hence, ΨT appears to be a useful indicator for grapevine management in both non-irrigated and irrigated vineyards.</p>

OENO One ◽  
2014 ◽  
Vol 48 (2) ◽  
pp. 123 ◽  
Author(s):  
José Manuel Mirás-Avalos ◽  
Emiliano Trigo-Córdoba ◽  
Yolanda Bouzas-Cid

<p style="text-align: justify;"><strong>Aims</strong>: To evaluate the usefulness of predawn water potential (<strong>Ψ</strong><sub>pd</sub>) to assess the water status of Galician grapevine cultivars for irrigation purposes.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Three Galician white grapevine cultivars (Albariño, Godello and Treixadura) were subjected to rain-fed and irrigation conditions during the 2013 growing season. Diurnal changes in leaf water potential (<strong>Ψ</strong><sub>l</sub>) were measured using a pressure chamber on days with high evapotranspiration demand. Stem water potential (<strong>Ψ</strong><sub>s</sub>) was measured at midday. <strong>Ψ</strong><sub>pd</sub> was not able to discriminate between treatments, whereas <strong>Ψ</strong><sub>l</sub> and <strong>Ψ</strong><sub>s</sub> at midday were able to detect significant differences in water status among plants.</p><p style="text-align: justify;"><strong>Conclusion</strong>: <strong>Ψ</strong><sub>pd</sub> was not useful to evaluate vine water status under the Galician climatic conditions. In contrast, both <strong>Ψ</strong><sub>l</sub> and <strong>Ψ</strong><sub>s</sub> were effective for detecting differences between treatments and can thus be used for irrigation management purposes.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: This is the first study evaluating water status of Galician grapevine cultivars. It also provides useful information about the strategy for its control through measurements of midday <strong>Ψ</strong>l or <strong>Ψ</strong>s.</p>


2002 ◽  
Vol 127 (3) ◽  
pp. 448-454 ◽  
Author(s):  
L.E. Williams ◽  
F.J. Araujo

A study was conducted to compare three measurements of determining water status of grapevines (Vitis vinifera L.) in the field. Predawn leaf water potential (ΨPD), midday leaf water potential (Ψl), and midday stem water potential (Ψstem) were measured on `Chardonnay' and `Cabernet Sauvignon' grapevines grown in Napa Valley, California late in the 1999 growing season. Both cultivars had been irrigated weekly at various fractions (0, 0.5, and 1.0 for `Chardonnay' and 0, 0.5, 0.75, and 1.5 for `Cabernet') of estimated vineyard evapotranspiration (ETc) from approximately anthesis up to the dates of measurements. Predawn water potential measurements were taken beginning at 0330 hr and completed before sunrise. Midday Ψl and Ψstem measurements were taken only between 1230 and 1330 hr. In addition, net CO2 assimilation rates (A) and stomatal conductance to water vapor (gs) were also measured at midday. Soil water content (SWC) was measured in the `Chardonnay' vineyard using a neutron probe. Values obtained for ΨPD, Ψl, and Ψstem in this study ranged from about -0.05 to -0.8, -0.7 to -1.8, and -0.5 to -1.6 MPa, respectively. All three measurements of vine water status were highly correlated with one another. Linear regression analysis of Ψl and Ψstem versus ΨPD resulted in r2 values of 0.88 and 0.85, respectively. A similar analysis of Ψl as a function of Ψstem resulted in an r2 of 0.92. In the `Chardonnay' vineyard, all three methods of estimating vine water status were significantly (P < 0.01) correlated with SWC and applied amounts of water. Lastly, ΨPD, Ψl, and Ψstem were all linearly correlated with measurements of A and gs at midday. Under the conditions of this study, ΨPD, Ψl, and Ψstem represent equally viable methods of assessing the water status of these grapevines. They were all correlated similarly with the amount of water in the soil profile and leaf gas exchange as well as with one another.


2009 ◽  
Vol 66 (4) ◽  
pp. 436-446 ◽  
Author(s):  
Claudia Rita de Souza ◽  
Luís Henrique Bassoi ◽  
José Moacir Pinheiro Lima Filho ◽  
Fabrício Francisco Santos da Silva ◽  
Leandro Hespanhol Viana ◽  
...  

There is an increased demand for high quality winegrapes in the São Francisco Valley, a new wine producing area in Brazil. As the grape quality is closely linked to the soil water status, understanding the effects of rootstock and irrigation management on grapevine water relations is essential to optimize yield and quality. This study was carried out to investigate the effects of irrigation strategies and rootstocks on water relations and scion vigour of field-grown grapevines in Petrolina, Pernambuco state, Brazil. The cultivars used as scions are Moscato Canelli and Syrah, both grafted onto IAC 572 and 1103 Paulsen rootstocks. The following water treatments were used: deficit irrigation, with holding water after veraison; and partial root-zone drying, supplying (100% of crop evapotranspiration) of the water loss to only one side of the root system after fruit set, alternating the sides periodically (about 24 days). In general, all treatments had values of pre-dawn leaf water potential higher than -0.2 MPa, suggesting absence of water stress. The vine water status was more affected by rootstock type than irrigation strategies. Both cultivars grafted on IAC 572 had the highest values of midday leaf water potential and stem water potential, measured on non-transpiring leaves, which were bagged with both plastic sheet and aluminum foil at least 1 h before measurements. For both cultivars, the stomatal conductance (g s), transpiration (E) and leaf area index (LAI) were also more affected by roostsotck type than by irrigation strategies. The IAC 572 rootstock presented higher g s, E and LAI than the 1103 Paulsen. Differences in vegetative vigor of the scion grafted onto IAC 572 rootstocks were related to its higher leaf specific hydraulic conductance and deeper root system as compared to the 1103 Paulsen, which increased the water-extraction capability, resulting in a better vine water status.


2009 ◽  
Vol 66 (3) ◽  
pp. 287-292 ◽  
Author(s):  
Antonio Odair Santos ◽  
Oren Kaye

Leaf water potential is a measure commonly used to describe crop water status and water stress dynamics. The established method for determining leaf water potential using a pressure chamber is cumbersome and subject to operator error as well as time/temperature limitations. These limitations prohibit the intensive sampling required to support proactive water management of commercial crops, including vineyards. Particular for grapevines there is need for faster, more precise and more reliable tools for determining leaf water potential in the field. Portable Near-infrared spectroscopy and multivariate data analysis were applied for the modeling and prediction of leaf water potential in grapevines. For field-grown wine grapes the most significant and intensive leaf absorptions occurs in the region from 1440 to 1950 nm and again beyond 2,200 nm. Multivariate analysis of these spectra, referenced against pressure chamber measurements as a standard, showed correlation coefficients from 0.87 to 0.95 clearly demonstrated that this technology can provide a fast and reasonable assessment of leaf water potential in the field.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 499B-499
Author(s):  
Ken Shackel ◽  
David Paige

In a number of tree crops, we have found that the water potential of lower canopy, nontranspiring leaves, measured with the pressure chamber at midday (midday stem water potential), is an excellent index of plant water stress and can be used for irrigation scheduling. Because stem water potential is typically much higher than transpiring leaf water potential, a lower pressure is required for the measurement, allowing us to design and build a lightweight device that could be easily operated by hand. The prototype was designed for pressures up to 2 MPa, which is sufficient for most irrigation conditions. A number of design features were incorporated into the sealing gland to eliminate the need for retightening during the pressurization process, reduce the amount of tissue external to the pressure chamber, and allow a greater visibility of the petiole. Identical values to those obtained with the standard, compressed nitrogen pressure chamber were obtained over the entire 2-MPa range, and the time required using either device under field conditions was the same (about 1 min per measurement). A number of alternative protocols were tested, and we found that even substantial recutting of the petiole had no influence on the measured water potential, contrary to popular belief. We also found that the same sample could be remeasured multiple times (five), with no net change in the water potential, allowing the measurement to be checked if necessary. This device should be of great utility in field irrigation management.


1999 ◽  
Vol 50 (7) ◽  
pp. 1225 ◽  
Author(s):  
J. A. Palta ◽  
Z. Plaut

The effect of transient water deficits on seed yield and components of seed yield of narrow-leafed lupin was measured in plants grown in a controlled environment under simulated field conditions. Lupins were grown in large columns of soil and transient water deficits were induced at pod set on the mainstem and first-order apical branches by withholding water for a 5-day period. Soil water content, leaf water potential, turgor pressure, and leaf conductance declined similarly during each period of transient water deficit. Differences in these parameters were apparent 2 days after water was withheld, and over the 5-day period, leaf water potential declined to −1.3 MPa and leaf conductance fell to 44% of the well-watered controls. Total dry matter per plant was reduced by the transient water deficit treatments. The reduction resulted from less accumulation of dry matter on the first, second, and third order apical branches. Leaf area on these branches was also reduced by abscission of the leaves after the water deficit was released. Seed yield per plant after each period of transient water deficit was reduced by 30–33%, relative to the well-watered controls. The reduction was largely due to a reduction in seed yield on the branches, mainly because they had fewer pods and seeds per pod. Seed dry weight and harvest index were not significantly affected by each period of transient water deficit. We conclude that differences in final seed yield between the well- watered controls and the transient water deficit treatments resulted from differences in pod number and seeds per pod. Low dry matter accumulation and reduction in leaf area on the first- and second-order apical branches under the transient water deficit were associated with the differences. Whereas the differences in pod number generated differences in the size of the reproductive sink, the differences in leaf area generated differences in the source capacity for assimilates for pod set and pod-filling.


1979 ◽  
Vol 15 (4) ◽  
pp. 377-383 ◽  
Author(s):  
M. V. K. Sivakumar ◽  
S. M. Virmani

SUMMARYThe pressure-chamber technique has been used for the first time to measure leaf-water potentials in chickpea under field conditions. Available soil-water contents at different depths for irrigated and non-irrigated crops are presented along with the diurnal variation in leaf-water status, to show that pressure-chamber measurements correspond closely with available soil water. Leaf-water potential has also shown differences in leaf-water status among different cultivars. The rapidity and ease with which measurements can be made in the field make the technique suitable for quick measurements of leaf-water status for chickpea.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 53
Author(s):  
Alson Time ◽  
Edmundo Acevedo

The effect of water deficit on growth, water status and stomatal functioning of Prosopis tamarugo was investigated under controlled water conditions. The study was done at the Antumapu Experiment Station of the University of Chile. Three levels of water stress were tested: (i) well-watered (WW), (ii) medium stress intensity (low-watered (LW)) and (iii) intense stress (non-watered (NW)), with 10 replicates each level. All growth parameters evaluated, such as twig growth, specific leaf area and apical dominance index, were significantly decreased under water deficit. Tamarugo twig growth decreased along with twig water potential. The stomatal conductance and CO2 assimilation decreased significantly under the water deficit condition. Tamarugo maintained a high stomatal conductance at low leaf water potential. In addition, tamarugo reduced its leaf area as a strategy to diminish the water demand. These results suggest that, despite a significant decrease in water status, tamarugo can maintain its growth at low leaf water potential and can tolerate intense water deficit due to a partial stomatal closing strategy that allows the sustaining of CO2 assimilation in the condition of reduced water availability.


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