Effect of pruning and plant spacing on the growth of cherry rootstocks and their influence on stem water potential of sweet cherry trees

The present work evaluates the main adaptive mechanisms developed by young sweet cherry trees (Prunus avium L.) to cope with drought. For this purpose, the young trees were subjected to two drought cycles with different water stress intensities followed by a recovery period. Three irrigation treatments were applied: control treatment (CTL) irrigated to ensure non-limiting soil water conditions; moderate water stress (MS) subjected to two drying cycles whose duration was dependent on the time elapsed until the trees reached values of midday stem water potential (Ψstem) of −1.3 and −1.7 MPa for the first and second cycle, respectively; and severe water stress (SS) similar to MS, but with reference values of −1.6 and −2.5 MPa. In-between drought cycles, MS and SS trees were irrigated daily as the CTL trees until reaching Ψstem values similar to those of CTL trees. The MS and SS trees showed an important stomatal regulation and lower vegetative growth. The decreasing leaf turgor potential (Ψturgor) during the drought periods accounted for 40–100% of the reduction in leaf water potential at midday (Ψmd). The minimum osmotic potential for mature leaves was about 0.35 MPa lower than in well-irrigated trees. The occasional osmotic adjustment observed in MS and SS trees was not sufficient to maintain Ψturgor values similar to the CTL trees or to increase the specific leaf weight (SLW). The leaf insertion angle increased as the water stress level increased. Severe water stress (Ψstem < −2.0 MPa) resulted in clear early defoliation as a further step in water conservation.

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

Sustainability ◽

10.3390/su13041759 ◽

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.

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

Remote Sensing ◽

10.3390/rs13091837 ◽

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).

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Potential of UAS-Based Remote Sensing for Estimating Tree Water Status and Yield in Sweet Cherry Trees

Remote Sensing ◽

10.3390/rs12152359 ◽

2020 ◽

Vol 12 (15) ◽

pp. 2359

Author(s):

Víctor Blanco ◽

Pedro José Blaya-Ros ◽

Cristina Castillo ◽

Fulgencio Soto-Vallés ◽

Roque Torres-Sánchez ◽

...

Keyword(s):

Remote Sensing ◽

Deficit Irrigation ◽

Vegetation Index ◽

Sweet Cherry ◽

Prunus Avium ◽

Water Status ◽

Control Treatment ◽

Stem Water Potential ◽

Irrigation Treatments ◽

Cherry Trees

The present work aims to assess the usefulness of five vegetation indices (VI) derived from multispectral UAS imagery to capture the effects of deficit irrigation on the canopy structure of sweet cherry trees (Prunus avium L.) in southeastern Spain. Three irrigation treatments were assayed, a control treatment and two regulated deficit irrigation treatments. Four airborne flights were carried out during two consecutive seasons; to compare the results of the remote sensing VI, the conventional and continuous water status indicators commonly used to manage sweet cherry tree irrigation were measured, including midday stem water potential (Ψs) and maximum daily shrinkage (MDS). Simple regression between individual VIs and Ψs or MDS found stronger relationships in postharvest than in preharvest. Thus, the normalized difference vegetation index (NDVI), resulted in the strongest relationship with Ψs (r2 = 0.67) and MDS (r2 = 0.45), followed by the normalized difference red edge (NDRE). The sensitivity analysis identified the optimal soil adjusted vegetation index (OSAVI) as the VI with the highest coefficient of variation in postharvest and the difference vegetation index (DVI) in preharvest. A new index is proposed, the transformed red range vegetation index (TRRVI), which was the only VI able to statistically identify a slight water deficit applied in preharvest. The combination of the VIs studied was used in two machine learning models, decision tree and artificial neural networks, to estimate the extra labor needed for harvesting and the sweet cherry yield.

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Usefulness of early morning stem water potential as a sensitive indicator of water status of deficit-irrigated grapevines (Vitis vinifera L.)

Scientia Horticulturae ◽

10.1016/j.scienta.2015.04.034 ◽

2015 ◽

Vol 191 ◽

pp. 10-14 ◽

Cited By ~ 10

Author(s):

Jason Cole ◽

Vinay Pagay

Keyword(s):

Vitis Vinifera ◽

Water Potential ◽

Water Status ◽

Early Morning ◽

Sensitive Indicator ◽

Vitis Vinifera L ◽

Stem Water Potential ◽

Stem Water

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Crop load affects assimilation rate, stomatal conductance, stem water potential and water relations of field-grown Sauvignon blanc grapevines

Journal of Experimental Botany ◽

10.1093/jxb/48.9.1675 ◽

1997 ◽

Vol 48 (9) ◽

pp. 1675-1680 ◽

Cited By ~ 39

Author(s):

A. Naor ◽

Y. Gal ◽

B. Bravdo

Keyword(s):

Stomatal Conductance ◽

Water Potential ◽

Water Relations ◽

Assimilation Rate ◽

Stem Water Potential ◽

Crop Load ◽

Sauvignon Blanc ◽

Stem Water

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

10.5194/egusphere-egu21-2187 ◽

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

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.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.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.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.Determination coefficients of r2=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.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&#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, (r2=0.60 NDWI in 2018), as well as greater differences in terms of water stress presented in the vineyard.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.

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Estimation of water stress in olive orchards through remote sensing data analysis

10.5194/egusphere-egu21-9521 ◽

2021 ◽

Author(s):

Luz Karime Atencia ◽

María Gómez del Campo ◽

Gema Camacho ◽

Antonio Hueso ◽

Ana M. Tarquis

Keyword(s):

Remote Sensing ◽

Water Stress ◽

Water Potential ◽

Statistical Tests ◽

Remote Sensing Data ◽

Olive Tree ◽

Fruit Trees ◽

Data Sets ◽

Stem Water Potential ◽

Stem Water

Olive is the main fruit tree in Spain representing 50% of the fruit trees surface, around 2,751,255 ha. Due to its adaptation to arid conditions and the scarcity of water, regulated deficit irrigation (RDI) strategy is normally applied in traditional olive orchards and recently to high density orchards. The application of RDI is one of the most important technique used in the olive hedgerow orchard. An investigation of the detection of water stress in nonhomogeneous olive tree canopies such as orchards using remote sensing imagery is presented.In 2018 and 2019 seasons, data on stem water potential were collected to characterize tree water state in a hedgerow olive orchard cv. Arbequina located in Chozas de Canales (Toledo). Close to the measurement&#8217;s dates, remote sensing images with spectral and thermal sensors were acquired. Several vegetation indexes (VI) using both or one type of sensors were estimated from the areas selected that correspond to the olive crown avoiding the canopy shadows.Nonparametric statistical tests between the VIs and the stem water potential were carried out to reveal the most significant correlation. The results will be discussing in the context of robustness and sensitivity between both data sets at different phenological olive state.ACKNOWLODGEMENTSFinancial support provided by the Spanish Research Agency co-financed with European Union FEDER funds (AEI/FEDER, UE, AGL2016-77282-C3-2R project) and Comunidad de Madrid through calls for grants for the completion of Industrial Doctorates, is greatly appreciated.

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ESTABLISHING REFERENCE VALUES OF TRUNK DIAMETER FLUCTUATIONS AND STEM WATER POTENTIAL FOR IRRIGATION SCHEDULING OF OLIVE TREES

Acta Horticulturae ◽

10.17660/actahortic.2004.664.51 ◽

2004 ◽

pp. 407-412 ◽

Cited By ~ 28

Author(s):

A. Moriana ◽

E. Fereres

Keyword(s):

Water Potential ◽

Reference Values ◽

Irrigation Scheduling ◽

Stem Water Potential ◽

Trunk Diameter ◽

Stem Water ◽

Olive Trees ◽

Trunk Diameter Fluctuations

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Unexpected relationships between δ13C and wine grape performance in organic farming

OENO One ◽

10.20870/oeno-one.2013.47.4.1556 ◽

2013 ◽

Vol 47 (4) ◽

pp. 269 ◽

Cited By ~ 5

Author(s):

Edoardo Antonio Costantino Costantini ◽

Alessandro Agnelli ◽

Pierluigi Bucelli ◽

Aldo Ciambotti ◽

Valentina Dell’Oro ◽

...

Keyword(s):

Water Stress ◽

Water Potential ◽

Soil Water ◽

Organic Farming ◽

Water Availability ◽

Stress Conditions ◽

Soil Water Availability ◽

Wine Grape ◽

Stem Water Potential ◽

Stem Water

Aim: To evaluate the relationship between carbon isotope ratio (δ13C) and wine grape viticultural and oenological performance in organic farming.Methods and results: The study was carried out for four years in the Chianti Classico wine production district (Central Italy), on five non irrigated vineyards conducted in organic farming. The reference variety was Sangiovese. Eleven sites were chosen for vine monitoring and grape sampling. The performance parameters were alcohol and must sugar content, sugar accumulation rate, mean berry weight, and extractable polyphenols. δ13C, stem water potential, and soil water availability were also monitored. Finally, soil nitrogen as well as yeast available nitrogen in the must were measured. δ13C was directly related to stem water potential and soil water deficit, and indicated a range of water stress conditions from none and moderate to strong. However, its relationship with viticultural and oenological results was contrary to expectation, that is, performance linearly increased along with soil moisture. On the other hand, the worst performance was obtained where both water and nitrogen were more limiting.Conclusions: The unexpected relationship between δ13C and Sangiovese performance was caused by low nitrogen availability. The studied sites all had low-fertility soils with poor or very poor nitrogen content. Therefore, in the plots where soil humidity was relatively higher, nitrogen plant uptake was favoured, and Sangiovese performance improved. Macronutrient being the main limiting factor, the performance was not lower in the plots where soil water availability was relatively larger. Therefore, the best viticultural result was obtained with no water stress conditions, at low rather than at intermediate δ13C values.Significance and impact of the study: Water nutrition is crucial for wine grape performance. δ13C is a method used to assess vine water status during the growing season and to estimate vine performance. A good performance is expected at moderate stress and intermediate δ13C values. A better knowledge of the interaction between water and nutrient scarcity is needed, as it can affect the use of δ13C to predict vine performance.

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