scholarly journals Daily stem diameter variations can predict the canopy water status of mature temperate trees

2018 ◽  
Vol 38 (7) ◽  
pp. 941-952 ◽  
Author(s):  
Lars Dietrich ◽  
Roman Zweifel ◽  
Ansgar Kahmen
Keyword(s):  
Water Status ◽  
Stem Diameter ◽  
Temperate Trees ◽  
Canopy Water ◽  
Stem Diameter Variations

scholarly journals EFFECT OF STEM AGE ON THE RESPONSE OF STEM DIAMETER VARIATIONS TO PLANT WATER STATUS IN TOMATO

2012 ◽  
pp. 907-914 ◽  
Author(s):  
J. Hanssens ◽  
T. De Swaef ◽  
K. Steppe ◽  
K. Goen ◽  
F. De Nayer ◽  
...  
Keyword(s):  
Water Status ◽  
Plant Water Status ◽  
Stem Diameter ◽  
Plant Water ◽  
Stem Diameter Variations

Functional unfold principal component analysis for automatic plant-based stress detection in grapevine

2012 ◽  
Vol 39 (6) ◽  
pp. 519 ◽  
Author(s):  
Annelies Baert ◽  
Kris Villez ◽  
Kathy Steppe
Keyword(s):  
Principal Component Analysis ◽  
Data Analysis ◽  
Drought Stress ◽  
Water Status ◽  
Multivariate Time Series ◽  
Principal Component ◽  
Component Analysis ◽  
Stem Diameter ◽  
Optimal Linear ◽  
Stem Diameter Variations

Detection of drought stress is of great importance in grapevines because the plant’s water status strongly affects the quality of the grapes and hence, resulting wine. Measurements of stem diameter variations show promise for detecting drought stress, but they depend strongly on microclimatic changes. Tools for advanced data analysis might be helpful to distinguish drought from microclimate effects. To this end, we explored the possibilities of two data mining techniques: Unfold principal component analysis (UPCA) – an already established tool in several biotechnological domains – and functional unfold principal component analysis (FUPCA) – a newer technique combining functional data analysis with UPCA. With FUPCA, the original, multivariate time series of variables are first approximated by fitting the least-squares optimal linear combination of orthonomal basis functions. The resulting coefficients of these linear combinations are then subjected to UPCA. Both techniques were used to detect when the measured stem diameter variations in grapevine deviated from their normal conditions due to drought stress. Stress was detected with both UPCA and FUPCA days before visible symptoms appeared. However, FUPCA is less complex in the statistical sense and more robust than original UPCA modelling. Moreover, FUPCA can handle days with missing data, which is not possible with UPCA.

scholarly journals Comparison of Stem Diameter Variations in Three Small Ornamental Shrubs under Water Stress

HortScience ◽  
2010 ◽  
Vol 45 (11) ◽  
pp. 1681-1689 ◽  
Author(s):  
Julián Miralles-Crespo ◽  
María J. Sánchez-Blanco ◽  
Alejandra Navarro G. ◽  
Juan J. Martínez-Sánchez ◽  
Jose A. Franco L. ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Status ◽  
Early Summer ◽  
Stem Growth ◽  
Stem Diameter ◽  
Stress Recovery ◽  
Plant Water ◽  
Mediterranean Shrubs ◽  
Ornamental Shrubs ◽  
Stem Diameter Variations

The dendrometer has been proposed as a sensitive plant water indicator based on stem growth. However, studies including dendrometers have been mainly focused on fruit trees and less attention has been paid to ornamental shrubs (small plants). In the study described here, stem dendrometers were used to ascertain whether there is any relationship between water status and dendrometric indices in potted ornamental shrubs (1 to 2 cm diameter). For this purpose, three Mediterranean shrubs (Pittosporum tobira, Callistemon citrinus, and Rhamnus alaternus) were studied under water stress recovery conditions in winter, spring, and early summer. At the end of the experiment, an extreme water stress treatment, which resulted in plant death (August) was also studied. Stem diameter variations [maximum and minimum daily stem values (MXDS and MNDS, respectively), maximum daily shrinkage (MDS), and stem growth rate (SGR)], daily evapotranspiration (daily plant ET), and leaf water potential (Ψleaf) parameters were considered throughout the experiment. A regression analysis between dendrometric indices and daily plant ET showed that MXDS and MNDS were sensitive under water stress recovery conditions, especially in severe environmental conditions (spring and summer). The SGR in C. citrinus, the MDS in P. tobira, and both indices in R. alaternus were seen to be sensitive during the stress to death period. Although more studies are needed, the results confirm that the use of dendrometers in small plants may be useful to provide continuous and automated registers of the plant water status under different substrate water content and climatic conditions. However, the response of these indices may imply moderate water stress.

scholarly journals Signal Intensity of Stem Diameter Variation for the Diagnosis of Drip Irrigation Water Deficit in Grapevine

Horticulturae ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 154
Author(s):  
Chen Ru ◽  
Xiaotao Hu ◽  
Wene Wang ◽  
Hui Ran ◽  
Tianyuan Song ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Signal Intensity ◽  
Signal To Noise Ratio ◽  
Water Status ◽  
Stem Diameter ◽  
Vegetative Stage ◽  
Signal To Noise ◽  
Diameter Variation ◽  
Expansion Stage ◽  
Noise Ratio

Precise irrigation management of grapevines in greenhouses requires a reliable method to easily quantify and monitor the grapevine water status to enable effective manipulation of the water stress of the plants. This study describes a study on stem diameter variations of grapevine planted in a greenhouse in the semi-arid area of Northwest China. In order to determine the applicability of signal intensity of stem diameter variation to evaluate the water status of grapevine and soil. The results showed that the relative variation curve of the grapevine stem diameter from the vegetative stage to the fruit expansion stage showed an overall increasing trend. The correlations of MDS (maximum daily shrinkage) and DI (daily increase) with meteorological factors were significant (p < 0.05), and the correlations with SWP, RWC and soil moisture were weak. Although MDS and DI can diagnose grapevine water status in time, SIMDS and SIDI have the advantages of sensitivity and signal intensity compared with other indicators. Compared with MDS and DI, the R2 values of the regression equations of SIMDS and SIDI with SWP and RWC were high, and the correlation reached a very significant level (p < 0.01). Thus, SIMDS and SIDI are more suitable for the diagnosis of grapevine water status. The SIMDS peaked at the fruit expansion stage, reaching 0.957–1.384. The signal-to-noise ratio of SIDI was higher than that of MDS across the three treatments at the vegetative stage. The value and signal-to-noise ratio of SIDI at the flowering stage were similar to those of SIMDS, while the correlation between SIDI and the soil moisture content was higher than that of SIMDS. It can be concluded that that SIDI is suitable as an indicator of water status of grapevine and soil during the vegetative and flowering stages. In addition, the signal-to-noise ratio of SIMDS during the fruit expansion and mature stages was significantly higher than that of SIDI. Therefore, SIMDS is suitable as an indicator of the moisture status of grapevine and soil during the fruit expansion and mature stages. In general, SIMDS and SIDI were very good predictors of the plant water status during the growth stage and their continuous recording offers the promising possibility of their use in automatic irrigation scheduling in grapevine.

scholarly journals A new validation of the Scholander pressure chamber technique based on stem diameter variations

2001 ◽  
Vol 52 (359) ◽  
pp. 1361-1365 ◽  
Author(s):  
Hervé Cochard ◽  
Sébastien Forestier ◽  
Thierry Améglio
Keyword(s):  
Pressure Chamber ◽  
Stem Diameter ◽  
Chamber Technique ◽  
Stem Diameter Variations

scholarly journals The feasibility of hand-held thermal and UAV-based multispectral imaging for canopy water status assessment and yield prediction of irrigated African eggplant (Solanum aethopicum L)

2021 ◽  
Vol 245 ◽  
pp. 106584
Author(s):  
Paul Reuben Mwinuka ◽  
Boniface P. Mbilinyi ◽  
Winfred B. Mbungu ◽  
Sixbert K. Mourice ◽  
H.F. Mahoo ◽  
...  
Keyword(s):  
Multispectral Imaging ◽  
Water Status ◽  
Yield Prediction ◽  
Status Assessment ◽  
Canopy Water

ROLE OF WATER AND CARBON IN TREE STEM DIAMETER VARIATIONS: A DOUBLE-GIRDLING EXPERIMENT

2005 ◽  
pp. 269-273 ◽  
Author(s):  
F.A. Daudet ◽  
T. Améglio ◽  
H. Cochard ◽  
O. Archilla ◽  
A. Lacointe
Keyword(s):  
Stem Diameter ◽  
Tree Stem ◽  
Stem Diameter Variations
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