scholarly journals Terrestrial laser scanning intensity captures diurnal variation in leaf water potential

2021 ◽  
Vol 255 ◽  
pp. 112274
Author(s):  
S. Junttila ◽  
T. Hölttä ◽  
E. Puttonen ◽  
M. Katoh ◽  
M. Vastaranta ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Leaf Water

scholarly journals Terrestrial Laser Scanning Intensity Captures Diurnal Variation in Leaf Water Potential

2020 ◽  
Author(s):  
Samuli Junttila ◽  
Teemu Hölttä ◽  
Eetu Puttonen ◽  
Masato Katoh ◽  
Mikko Vastaranta ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Tree Species ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Leaf Water ◽  
Water Dynamics ◽  
Plant Water ◽  
Plant Mortality

Drought-induced plant mortality has increased globally during the last decades and is forecasted to influence global vegetation dynamics. Timely information on plant water dynamics is essential for understanding and anticipating drought-induced plant mortality. The most common metric that has been used for decades for measuring water stress is leaf water potential (ΨL), which is measured destructively. To obtain information on water dynamics from trees and forested landscapes, remote sensing methods have been developed. However, the spatial and temporal resolution of the existing methods have limited our understanding of water dynamics and diurnal variation of ΨL within single trees. Thus, we investigated the capability of terrestrial laser scanning (TLS) intensity in observing diurnal variation in ΨL during a 50 hour monitoring period and aimed to improve understanding on how large part of the diurnal variation in ΨL can be captured using intensity observations. We found that TLS intensity at 905 nm wavelength was able to explain 78% of the variation in ΨL for three trees of two tree species with a root-mean square error of 0.137 MPa. Based on our experiment with three trees, time-series of TLS intensity measurements can be used in detecting changes in ΨL, and thus it is worthwhile to expand the investigations to cover a wider range of tree species and forests and further increase our understanding of plant water dynamics at wider spatial and temporal scales.

Effects of Different Irrigation Amounts on Water Use of Precocious Walnuts

2014 ◽  
Vol 651-653 ◽  
pp. 1423-1431
Author(s):  
Hua Bing Ma ◽  
Mei Mei Li ◽  
Jun Jie Ren ◽  
Bao Guo Li ◽  
Guo Hui Qi
Keyword(s):  
Diurnal Variation ◽  
Water Use Efficiency ◽  
Water Potential ◽  
Soil Water ◽  
Water Use ◽  
Leaf Water Potential ◽  
Sap Flow ◽  
Leaf Water ◽  
Flow Rates ◽  
Use Efficiency

Objective : To provide scientific guidance for water management of precocious walnuts. Method: With 8 years old ‘Lvling’ walnut trees as samples, 5 irrigation quantity treatments were designed, including 0, 15, 30, 45 and 60 kg of water per plant for each time, respectively and the routine irrigation amount (CK) was 600 kg of water per plant for each time. During the draught stage in growing season, 3 times of irrigation were carried out, and the effects of different treatments on sap flow, water use efficiency, yield and fruit quality were compared. Results: The daily instantaneous maximum average sap flow rates were found with 60 kg of water and control; the daily highest average water use efficiency was 1.54 mmol/mol with the treatment of 30 kg water; the daily highest average leaf water potential was-1.23 MPa with control; the highest yield per plant (1.48 kg) was found with the control, and the yield of 45 kg and 60 kg water per plant one time accounted for 98.65% and 99.32% of that of control, respectively. with T1 the yield was the lowest, only accounting for 70.65% of the control. Conclusion: As the soil water contents increased, the diurnal variation curve of sap flow rates changed from unimodal to bimodal patterns in sunny days, the main peak was narrowed; the curve of diurnal variation of leaf water potential changed from "V" to "W" type; the leaf water use efficiency increased initially and then decreased later; and the nut quality was improved and the yield increased. The optimal soil water content (SWC) of 'Lvling' precocious walnuts ranged from 20.01% ~ 21.96%.

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

Sampling Error for Leaf Water Potential Measurements in Wheat 1

Crop Science ◽  
1986 ◽  
Vol 26 (2) ◽  
pp. 380-383 ◽  
Author(s):  
R. C. Johnson ◽  
H. T. Nguyen ◽  
R. W. McNew ◽  
D. M. Ferris
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Sampling Error ◽  
Leaf Water ◽  
Water Potential Measurements

scholarly journals The Effect of Grapevine Age (Vitis vinifera L. cv. Zinfandel) on Phenology and Gas Exchange Parameters over Consecutive Growing Seasons

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 311
Author(s):  
Vegas Riffle ◽  
Nathaniel Palmer ◽  
L. Federico Casassa ◽  
Jean Catherine Dodson Peterson
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Management Practices ◽  
Leaf Water ◽  
Sugar Accumulation ◽  
Gas Exchange Parameters ◽  
Growing Season Length ◽  
Growing Seasons ◽  
Exchange Parameters

Unlike most crop industries, there is a strongly held belief within the wine industry that increased vine age correlates with quality. Considering this perception could be explained by vine physiological differences, the purpose of this study was to evaluate the effect of vine age on phenology and gas exchange parameters. An interplanted, dry farmed, Zinfandel vineyard block under consistent management practices in the Central Coast of California was evaluated over two consecutive growing seasons. Treatments included Young vines (5 to 12 years old), Control (representative proportion of young to old vines in the block), and Old vines (40 to 60 years old). Phenology, leaf water potential, and gas exchange parameters were tracked. Results indicated a difference in phenological progression after berry set between Young and Old vines. Young vines progressed more slowly during berry formation and more rapidly during berry ripening, resulting in Young vines being harvested before Old vines due to variation in the timing of sugar accumulation. No differences in leaf water potential were found. Young vines had higher mid-day stomatal conductance and tended to have higher mid-day photosynthetic rates. The results of this study suggest vine age is a factor in phenological timing and growing season length.

Photosynthesis Response of Sunlit and Shade Pepper (Capsicum annuum) Leaves at Different Positions in the Canopy Under Two Water Regimes

1994 ◽  
Vol 21 (3) ◽  
pp. 377 ◽  
Author(s):  
A Alvino ◽  
M Centritto ◽  
FD Lorenzi
Keyword(s):  
Water Potential ◽  
Capsicum Annuum ◽  
Leaf Water Potential ◽  
Co2 Exchange ◽  
Leaf Water ◽  
Predawn Leaf Water Potential ◽  
Water Regimes ◽  
Water Potentials ◽  
Sun And Shade ◽  
Shade Leaves

Pepper (Capsicum annuum L.) plants were grown in 1 m2 lysimeters under two different water regimes in order to investigate differences in the spatial arrangements of the leaves and to relate this to daily assimilation rates of leaves of the canopy. The control regime (well-watered (W) treatment) was irrigated whenever the accumulated 'A' pan evaporation reached 4 cm, whereas the water-stressed (S) treatment was watered whenever the predawn leaf water potential fell below -1 MPa. During the growing cycle, equal numbers of sun and shade leaves were chosen from the apical, middle and basal parts of the canopy, corresponding to groups of leaves of increasing age. The CO2 exchange rate (CER) was measured at 0830, 1230 and 1530 hours on 8 days along the crop cycle, on leaves in their natural inclination and orientation. Leaf water potentials were measured on apical leaves before dawn and concurrently with gas exchange measurements. Control plants maintained predawn leaf water potential at -0.3 MPa, but S plants reached values lower than -1.2 MPa. Midday leaf water potentials were about twice as low in the S plants as in the controls. Water stress reduced LA1 during the period of crop growth, and dry matter production at harvest. Stressed apical leaves appeared to reduce stress by changing their inclination. They were paraheliotropic around midday and diaheliotropic at 0830 and 1530 hours. The CER values of the S treatment were significantly lower than those of the W treatment in apical and middle leaves, whereas the CER of basal leaves did not differ in either treatments. In the S treatment, reduction in the CER values of sunlit apical leaves was more evident in the afternoon than at midday or early in the morning, whereas basal leaves were less affected by water than basal stress leaves if sunlit, and negligibly in shaded conditions.

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