Water relations of cut greenhouse roses: The relationships between stem water potential, hydraulic conductance and cavitation

1988 ◽  
Vol 36 (1-2) ◽  
pp. 109-118 ◽  
Author(s):  
M.A. Dixon ◽  
J.A. Butt ◽  
D.P. Murr ◽  
M.J. Tsujita
Keyword(s):  
Water Potential ◽  
Water Relations ◽  
Hydraulic Conductance ◽  
Stem Water Potential ◽  
Stem Water

Water stress and reduced fruit size in micro-irrigated pear trees under deficit partial rootzone drying

2007 ◽  
Vol 58 (7) ◽  
pp. 670 ◽  
Author(s):  
Mark G. O'Connell ◽  
Ian Goodwin
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Relations ◽  
Fruit Size ◽  
Leaf Conductance ◽  
Stem Water Potential ◽  
Crop Water ◽  
Reproductive Growth ◽  
Stem Water ◽  
Partial Rootzone Drying

Crop water relations, vegetative and reproductive growth, and soil water status were studied during 2 seasons to determine the effectiveness of partial rootzone drying (PRD) in a mature micro-irrigated pear orchard in the Goulburn Valley, Australia. PRD treatments were 50% (PRD50) and 100% (PRD100) of predicted crop water requirement (ETc) applied on one side of the tree alternated on a 14-day cycle compared with a Control treatment, which received 100% of ETc irrigated on both sides of the tree. Irrigation was applied daily by micro-jets to replace ETc estimated using reference crop evapotranspiration (ETo) and a FAO-56 crop coefficient of 1.15 adjusted for tree size. The PRD50 regime applied 174–250 mm for the season v. 347–470 mm for both the Control and PRD100 treatments. Irrigation maintained a well watered rootzone under the emitter compared with the drying profiles of the alternated wet/dry irrigated zones of the PRD treatments. There was no significant benefit of PRD100 compared with the Control irrigation regime. Similar vegetative growth (canopy radiation interception), reproductive growth (fruit growth rate, final fruit size, yield), fruit quality (total soluble solids, flesh firmness), and crop water relations (midday leaf conductance, midday leaf and stem water potential) were measured between the Control and PRD100. Trees under the PRD50 regime showed symptoms of severe water stress, that being greater fruit drop, reduced fruit size, lower yield, reduced leaf conductance, and lower leaf and stem water potential. The 50% water saving afforded by PRD50 led to a yield penalty of 16–28% compared with the Control and PRD100. PRD50 fruit failed to meet commercial cannery requirements due to poor fruit size. We conclude from an agronomic basis that deficit PRD irrigation management is not recommended for micro-irrigated pear orchards on fine-textured soils in the Goulburn Valley, Australia.

scholarly journals Variation in scion water relations mediated by two newly released Geneva series rootstocks

2021 ◽  
Author(s):  
Erica Casagrande Biasuz ◽  
Lee Kalcsits
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Water Relations ◽  
Isotope Composition ◽  
Water Status ◽  
Physiological Traits ◽  
Stem Water Potential ◽  
Carbon And Oxygen Isotope ◽  
Stem Water

Dwarfing rootstocks are used to control tree vigor allowing for increased densities that increase apple production. Although there is considerable variation among rootstocks in dwarfing capacity, the mechanisms by which rootstocks affect vigor in apple scions remains unclear. Here, Honeycrisp apple growth and water relations were compared among three rootstocks; M-9 as the industry standard and two less studied Geneva series rootstocks; G.87 and G. 814 in Washington, USA. Trees were acquired from a commercial nursery and planted in 2017. In 2018 and 2019, scion physiological, isotopic and morphological traits were measured to better understand the link between rootstock-driven vigor and physiological traits. Rootstock affected scion shoot growth (P <0.001), stomatal conductance (P< 0.01) and stem water potential (P <0.001). Rootstocks with low vegetative vigor like M.9 also had lower stomatal conductance and enriched leaf δ13C and δ18O isotope composition. Plant growth was positively correlated with stomatal conductance and stem water potential. Rootstocks also affected plant water status and net gas exchange. Here, we report an association between rootstock-induced vigor and scion physiological traits such as gas exchange, stem water potential, and leaf carbon and oxygen isotope composition. This research has implications for the understanding of the mechanisms of dwarfing by rootstocks in apple.

scholarly journals Rootstocks induce functional differences that affect carbon isotope discrimination and water relations in the apple scion

2021 ◽  
Author(s):  
Erica Casagrande Biasuz ◽  
Lee Kalcsits
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Carbon Isotope ◽  
Hydraulic Resistance ◽  
Water Relations ◽  
Water Movement ◽  
Isotope Composition ◽  
Leaf Gas Exchange ◽  
Stem Water Potential ◽  
Stem Water

Composite trees combine traits from both the rootstock and scion. Dwarfing rootstocks are used to reduce shoot vigor and improve fruit quality and productivity. Although differences in rootstock vigour have been clearly described, the underlying physiological mechanisms regulating scion vigor are not well understood. Plant water status is strongly influenced by stem hydraulic resistance to water movement. In the scion, stomata regulate transpiration rates and are essential to prevent hydraulic failure. Lower stomatal conductance contributes to enriched leaf carbon isotope composition (δ13C). Combined, the effects of increased hydraulic resistance, limited stomatal control, and subsequently, limited gas exchange can affect tree growth. These differences may also correspond to differences in scion vigor. Here, vegetative growth, gas exchange, stem water potential, and leaf δ13C were compared to determine how rootstocks affect scion water relations. B.9 had the lowest shoot vigor compared to the more vigorous rootstock, G.890. Similarly, photosynthetic rates were also lower. Rootstock vigor was closely associated with leaf gas exchange and stem water potential in the scion and were reflected in leaf δ13C signatures. Dwarfing was strongly related to hydraulic limitations induced by rootstock genotype and these changes are distinguishable when measuring leaf and stem δ13C composition.

scholarly journals Gas Exchange and Vine Water Relations are Crop Load Dependent

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 648d-648
Author(s):  
A. Naor ◽  
Y. Gal ◽  
B. Bravdo
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Water Relations ◽  
Shoot Density ◽  
Simultaneous Increase ◽  
Stem Water Potential ◽  
Sink Effect ◽  
Stem Water ◽  
The One ◽  
Root Permeability

The effect of shoot density and crop level on gas exchange and water relations of filed-grown Sauvignon blanc was studied. Ten and 44 shoots/vine and one and two clusters per shoot treatments were examined in a factorial design. The two-cluster treatments had higher stem water potential (Ystem), assimilation rate, and stomatal (gs) and nonstomatal (gm) conductance. A quantitative analysis suggests that capacitance cannot account for the simultaneous increase in gs and Ystem in the two clusters treatment. The two-cluster treatment had higher Ystem for similar transpiration rates (similar gs) compared to the one-cluster treatment. The similar transpiration rate and lower stem to root water potential difference in the two-cluster treatment was explained by increased root permeability in the two-cluster treatment. The similar gs–gm, in spite of a meaningful decrease of gs with decreasing Ystem, suggests that gs and gm synchronize themselves to perturbations of gm due to sink effect and gs due to water stress.

scholarly journals The Effect of Irrigation Rate on the Water Relations of Young Citrus Trees in High-Density Planting

2021 ◽  
Vol 13 (4) ◽  
pp. 1759
Author(s):  
Said A. Hamido ◽  
Kelly T. Morgan
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Soil Salinity ◽  
Planting Density ◽  
Stem Water Potential ◽  
Irrigation Rate ◽  
Biological Stress ◽  
Stem Water ◽  
Water Contents ◽  
Soil Water Contents

The availability and proper irrigation scheduling of water are some of the most significant limitations on citrus production in Florida. The proper volume of citrus water demand is vital in evaluating sustainable irrigation approaches. The current study aims to determine the amount of irrigation required to grow citrus trees at higher planting densities without detrimental impacts on trees’ water relation parameters. The study was conducted between November 2017 and September 2020 on young sweet orange (Citrus sinensis) trees budded on the ‘US-897’ (Cleopatra mandarin x Flying Dragon trifoliate orange) citrus rootstock transplanted in sandy soil at the Southwest Florida Research and Education Center (SWFREC) demonstration grove, near Immokalee, Florida. The experiment contained six planting densities, including 447, 598, and 745 trees per ha replicated four times, and 512, 717, and 897 trees per ha replicated six times. Each density treatment was irrigated at 62% or 100% during the first 15 months between 2017 and 2019 or one of the four irrigation rates (26.5, 40.5, 53, or 81%) based on the calculated crop water supplied (ETc) during the last 17 months of 2019–2020. Tree water relations, including soil moisture, stem water potential, and water supplied, were collected periodically. In addition, soil salinity was determined. During the first year (2018), a higher irrigation rate (100% ETc) represented higher soil water contents; however, the soil water content for the lower irrigation rate (62% ETc) did not represent biological stress. One emitter per tree regardless of planting density supported stem water potential (Ψstem) values between −0.80 and −0.79 MPa for lower and full irrigation rates, respectively. However, when treatments were adjusted from April 2019 through September 2020, the results substantially changed. The higher irrigation rate (81% ETc) represented higher soil water contents during the remainder of the study, the lower irrigation rate (26.5% ETc) represents biological stress as a result of stem water potential (Ψstem) values between −1.05 and −0.91 MPa for lower and higher irrigation rates, respectively. Besides this, increasing the irrigation rate from 26.5% to 81%ETc decreased the soil salinity by 33%. Although increasing the planting density from 717 to 897 trees per hectare reduced the water supplied on average by 37% when one irrigation emitter was used to irrigate two trees instead of one, applying an 81% ETc irrigation rate in citrus is more efficient and could be managed in commercial groves.

scholarly journals Towards Vine Water Status Monitoring on a Large Scale Using Sentinel-2 Images

2021 ◽  
Vol 13 (9) ◽  
pp. 1837
Author(s):  
Eve Laroche-Pinel ◽  
Sylvie Duthoit ◽  
Mohanad Albughdadi ◽  
Anne D. Costard ◽  
Jacques Rousseau ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Potential ◽  
Large Scale ◽  
Water Status ◽  
Vegetation Indices ◽  
Machine Learning Algorithms ◽  
Severe Drought ◽  
Stem Water Potential ◽  
Stem Water ◽  
Sentinel 2

Wine growing needs to adapt to confront climate change. In fact, the lack of water becomes more and more important in many regions. Whereas vineyards have been located in dry areas for decades, so they need special resilient varieties and/or a sufficient water supply at key development stages in case of severe drought. With climate change and the decrease of water availability, some vineyard regions face difficulties because of unsuitable variety, wrong vine management or due to the limited water access. Decision support tools are therefore required to optimize water use or to adapt agronomic practices. This study aimed at monitoring vine water status at a large scale with Sentinel-2 images. The goal was to provide a solution that would give spatialized and temporal information throughout the season on the water status of the vines. For this purpose, thirty six plots were monitored in total over three years (2018, 2019 and 2020). Vine water status was measured with stem water potential in field measurements from pea size to ripening stage. Simultaneously Sentinel-2 images were downloaded and processed to extract band reflectance values and compute vegetation indices. In our study, we tested five supervised regression machine learning algorithms to find possible relationships between stem water potential and data acquired from Sentinel-2 images (bands reflectance values and vegetation indices). Regression model using Red, NIR, Red-Edge and SWIR bands gave promising result to predict stem water potential (R2=0.40, RMSE=0.26).

Estimation water status of the vineyard by calculating multispectral index from satellite images

2021 ◽  
Author(s):  
Marta Rodríguez-Fernández ◽  
María Fandiño ◽  
Xesús Pablo González ◽  
Javier J. Cancela
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Spectral Index ◽  
Satellite Images ◽  
Irrigation System ◽  
Water Status ◽  
Stress Index ◽  
Stem Water Potential ◽  
Stem Water ◽  
Water Potential Measurements

&lt;p&gt;The estimation of the water status in the vineyard, is a very important factor, in which every day the winegrowers show more interest since it directly affects the quality and production in the vineyards. The situation generated by COVID-19 in viticulture, adds importance to tools that provide information of the hydric status of vineyard plants in a telematic way.&lt;/p&gt;&lt;p&gt;In the present study, the stem water potential in the 2018 and 2019 seasons, is analysed in a vineyard belonging to the Rias Baixas wine-growing area (Vilagarcia de Arousa, Spain), with 32 sampling points distributed throughout the plot, which allows the contrast and validation with the remote sensing methodology to estimate the water status of the vineyard using satellite images.&lt;/p&gt;&lt;p&gt;The satellite images have been downloaded from the Sentinel-2 satellite, on the closets available dates regarding the stem water potential measurements, carried out in the months of June to September, because this dates are considered the months in which vine plants have higher water requirements.&lt;/p&gt;&lt;p&gt;With satellite images, two spectral index related to the detection of water stress have been calculated: NDWI (Normalized Difference Water Index) and MSI (Moisture Stress Index). Stem water potential measurements, have allowed a linear regression with both index, to validate the use of these multispectral index to determine water stress in the vineyard.&lt;/p&gt;&lt;p&gt;Determination coefficients of r&lt;sup&gt;2&lt;/sup&gt;=0.62 and 0.67, have been obtained in July and August 2018 and 0.54 in June of 2019 for the NDWI index, as well as values of 0.53 and 0.63 in July 2018 and June 2019 respectively, when it has been analysed the MSI index.&lt;/p&gt;&lt;p&gt;Between both seasons, the difference observed, that implies slightly greater water stress in 2019, is reflected in the climate conditions during the summer months, with an average accumulated rainfall that doesn&amp;#8217;t exceed 46 mm of water. Although, the NDWI index has allowed to establish better relationships in the 2018 season respect to the MSI index and the 2019 season, (r&lt;sup&gt;2&lt;/sup&gt;=0.60 NDWI in 2018), as well as greater differences in terms of water stress presented in the vineyard.&lt;/p&gt;&lt;p&gt;With the spectral index calculated, it has been possible to validate the use of these index for the determination of the water stress of the vineyard plants, as an efficient, fast and less expensive method, which allows the application of an efficient irrigation system in the vineyard.&lt;/p&gt;

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