Effects of root severing treatments on loblolly pine

1988 ◽  
Vol 18 (11) ◽  
pp. 1376-1385 ◽  
Author(s):  
William C. Carlson ◽  
Constance A. Harrington ◽  
Peter Farnum ◽  
Stephen W. Hallgren
Keyword(s):  
Soil Moisture ◽  
Water Potential ◽  
Root System ◽  
Loblolly Pine ◽  
Water Status ◽  
Lateral Roots ◽  
Second Order ◽  
Plant Water Status ◽  
Plant Water ◽  
First Order

Six-year-old loblolly pine seedlings were subjected to root severing treatments varying from 0 to 100% of first-order lateral roots. Separate treatments severed surface-oriented or deep-oriented roots. Plant water status was monitored periodically for several months. After all measurements were taken, gross root system structure was determined by excavation. Treatment responses were evident on all dates of measurement. Relationships between percentage of root system cut and leaf conductance or water potential were stronger when surface-oriented roots were cut than when deep-oriented roots were cut. Severing surface-oriented first-order lateral (SOFOL) roots probably resulted in greater impact on plant water status than severing deep-oriented first-order lateral (DOFOL) roots because (i) SOFOL roots had both surface-oriented and deep-oriented second-order lateral roots that could tap both surface and subsurface soil horizons for soil moisture, and (ii) the deep-oriented second-order roots (originating from the SOFOL roots) were spatially distributed over a much larger area than the DOFOL roots and thus would have access to soil water in a larger volume of soil. For SOFOL roots the relationship between percentage cut and leaf conductance or transpiration was strongly negative; for DOFOL roots, no relationship between these variables was observed. Initially water potential decreased with the percentage of roots cut in both groups; in later measurements, water potential was affected more by severing SOFOL than DOFOL roots. Calculation of soil moisture depletion by depth indicated that both surface- and deep-oriented second-order lateral roots were important for water uptake. Severing SOFOL roots significantly decreased nitrogen, phosphorus, and potassium levels in needles of the first growth flush of the year. Levels of these elements in terminal buds were not affected by severing SOFOL roots, but were significantly reduced by severing DOFOL roots. Secondary xylem production was reduced proportionately to the amount of root system cross-sectional area severed.

scholarly journals Soilless Substrate Hydrology Can Be Engineered to Influence Plant Water Status for an Ornamental Containerized Crop Grown within Optimal Water Potentials

2018 ◽  
Vol 143 (4) ◽  
pp. 268-281 ◽  
Author(s):  
Jeb S. Fields ◽  
James S. Owen ◽  
James E. Altland ◽  
Marc W. van Iersel ◽  
Brian E. Jackson
Keyword(s):  
Hydraulic Conductivity ◽  
Water Potential ◽  
Loblolly Pine ◽  
Water Status ◽  
Crop Growth ◽  
Plant Water Status ◽  
Plant Water ◽  
Eastern United States ◽  
Water Potentials ◽  
Soilless Substrate

Water-efficient soilless substrates need to be engineered to address diminishing water resources. Therefore, we investigated soilless substrates with varying hydrologies to determine their influence on crop growth and plant water status. Aged loblolly pine (Pinus taeda) bark was graded into four particle size fractions. The coarsest fraction was also blended with either sphagnum peat or coir at rates that mimic static physical properties of the unfractionated bark or conventional substrate used by specialty crop producers within the eastern United States. Hibiscus rosa-sinensis ‘Fort Myers’ plugs were established in each of the seven substrates and maintained at optimal substrate water potentials (−50 to −100 hPa). After a salable crop was produced 93 days after transplanting, substrate was allowed to dry until plants completely wilted. Crop morphology and water use was affected by substrate hydrology. Increased substrate unsaturated hydraulic conductivity (K) allowed for plants to access higher proportions of water and therefore increased crop growth. Maintaining optimal substrate water potential allowed plants to be produced with <18 L water. Measurements of plant water availability showed that the substrate water potential at which the crop ceases to withdraw water varied among substrates. Pore uniformity and connectivity could be increased by both fibrous additions and particle fractionation, which resulted in increased substrate hydraulic conductivity (Ks). Plants grown in substrates with higher hydraulic conductivities were able to use more water. Soilless substrate hydrology can be modified and used in concert with more efficient irrigation systems to provide more water sustainability in container crop systems.

scholarly journals A minimally disruptive method for measuring water potential in planta using hydrogel nanoreporters

2021 ◽  
Vol 118 (23) ◽  
pp. e2008276118
Author(s):  
Piyush Jain ◽  
Weizhen Liu ◽  
Siyu Zhu ◽  
Christine Yao-Yun Chang ◽  
Jeff Melkonian ◽  
...  
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Water Status ◽  
Resonance Energy ◽  
Field Measurements ◽  
Leaf Water ◽  
Plant Water Status ◽  
Plant Water ◽  
In Planta

Leaf water potential is a critical indicator of plant water status, integrating soil moisture status, plant physiology, and environmental conditions. There are few tools for measuring plant water status (water potential) in situ, presenting a critical barrier for developing appropriate phenotyping (measurement) methods for crop development and modeling efforts aimed at understanding water transport in plants. Here, we present the development of an in situ, minimally disruptive hydrogel nanoreporter (AquaDust) for measuring leaf water potential. The gel matrix responds to changes in water potential in its local environment by swelling; the distance between covalently linked dyes changes with the reconfiguration of the polymer, leading to changes in the emission spectrum via Förster Resonance Energy Transfer (FRET). Upon infiltration into leaves, the nanoparticles localize within the apoplastic space in the mesophyll; they do not enter the cytoplasm or the xylem. We characterize the physical basis for AquaDust’s response and demonstrate its function in intact maize (Zea mays L.) leaves as a reporter of leaf water potential. We use AquaDust to measure gradients of water potential along intact, actively transpiring leaves as a function of water status; the localized nature of the reporters allows us to define a hydraulic model that distinguishes resistances inside and outside the xylem. We also present field measurements with AquaDust through a full diurnal cycle to confirm the robustness of the technique and of our model. We conclude that AquaDust offers potential opportunities for high-throughput field measurements and spatially resolved studies of water relations within plant tissues.

scholarly journals Determination of an efficient irrigation schedule for the cultivation of rose cv. Freedom under greenhouse conditions in Colombia

2014 ◽  
Vol 32 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Jhon Jairo Arévalo ◽  
Javier Enrique Vélez S. ◽  
Diego Sebastiano Intrigliolo
Keyword(s):  
Water Potential ◽  
Water Status ◽  
Irrigation Schedule ◽  
Experimental Period ◽  
Plant Water Status ◽  
Base Line ◽  
Plant Water ◽  
Stem Water Potential ◽  
Evaporative Demand ◽  
Stem Water

An experiment on rose (Rosa sp.) cv. Freedom was performed in a greenhouse on the Bogota Plateau, Colombia, to identify an efficient irrigation regime for this crop. The tested treatments were based on three irrigation doses, applying different fractions of the estimated crop evapotranspiration (ETc), calculated using a class A evaporation tank: i) 100% ETc (ETc100), ii) 80% ETc (ETc80) and iii) 70% ETc (ETc70). During the entire experimental period, from mid-May to early September, the crop had a constant production of floral stems. In all of the irrigation treatments, the soil and plant water status were monitored using tensiometers and the midday stem water potential, respectively (ystem). In the fully irrigated roses, the actual water use was determined using a drainage lysimeter in order to obtain the local crop coefficients (Kc) by means of a water balance. From June to August, the obtained monthly Kc values varied between 1.10 and 1.26. Compared to the ETc100 treatment, 14.5 and 21.8% less water was applied in treatments ETc80 and ETc70, respectively. Despite this fact, no statistically significant differences were found among the treatments for rose production or quality. Finally, in the more irrigated roses, tight relationships between the stem water potential and vapor pressure deficit were obtained. The reported base-line equations can be used for predicting the optimum rose plant water status, depending on the environmental conditions. Overall, the reported results can be used for an efficient irritation schedule for rose crops under greenhouse conditions, using the local Kc and direct determinations of plant water status corrected for the evaporative demand.

scholarly journals Correlation of Field-Measured and Remotely Sensed Plant Water Status as a Tool to Monitor the Risk of Drought-Induced Forest Decline

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 77 ◽  
Author(s):  
Daniel Marusig ◽  
Francesco Petruzzellis ◽  
Martina Tomasella ◽  
Rossella Napolitano ◽  
Alfredo Altobelli ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Forest Decline ◽  
Tree Mortality ◽  
Vegetation Index ◽  
Water Status ◽  
Remotely Sensed ◽  
Plant Water Status ◽  
Tree Level ◽  
Plant Water

Increased frequency of tree mortality and forest decline due to anomalous drought events calls for the adoption of effective monitoring of tree water status over large spatial and temporal scales. We correlated field-measured and remotely sensed plant water status parameters, to test the possibility of monitoring the risk of drought-induced dehydration and hydraulic failure using satellite images calibrated on reliable physiological indicators of tree hydraulics. The study was conducted during summer 2019 in the Karst plateau (NE Italy) in a woodland dominated by Fraxinus ornus L.; Sentinel-2 images were acquired on a seasonal scale on the same dates when absolute water content (AbWC), relative water content (RWC), and minimum water potential (Ψmin) were measured in the field. Plant water status parameters were correlated with normalized difference vegetation index (NDVI and NDVI 8A), normalized difference water index (NDWI), and soil-adjusted vegetation index (SAVI). Significant Pearson and Spearman linear correlations (α < 0.05) emerged between all tree-level measured variables and NDWI, while for NDVI, NDVI 8A, and SAVI no correlation was found. Our results suggest the possibility of using the NDWI as a proxy of tree water content and water potential.

Soil Moisture as Predictor of Plant Water Status

2021 ◽  
Vol 47 (3) ◽  
pp. 110-115
Author(s):  
Johannes Hertzler ◽  
Steffen Rust
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Water Status ◽  
Soil Water Potential ◽  
Irrigation Scheduling ◽  
Plant Water Status ◽  
Plant Water ◽  
Estimation Errors ◽  
Plant Available Water ◽  
The Relationship

Soil water potential can be used as a proxy for plant available water in irrigation scheduling. This study investigated the relationship between soil water potential and plant water status of pines (Pinus sylvestris L.) planted into two different substrates. Predawn leaf water potential as a well-established measure of the plant water status and soil water potential correlated very well. However, estimating the plant water status from individual sensor readings is subject to significant estimation errors. Furthermore, it was shown that heterogeneous soil/root ball combinations can lead to critical effects on the soil water balance, and that sensors installed outside of the root balls cannot estimate the plant water status without site-specific calibration.

scholarly journals A minimally disruptive method for measuring water potential in-planta using hydrogel nanoreporters

2020 ◽  
Author(s):  
Piyush Jain ◽  
Weizhen Liu ◽  
Siyu Zhu ◽  
Jeff Melkonian ◽  
Duke Pauli ◽  
...  
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Water Status ◽  
Resonance Energy ◽  
Field Measurements ◽  
Leaf Water ◽  
Plant Water Status ◽  
Plant Water ◽  
In Planta

AbstractLeaf water potential is a critical indicator of plant water status, integrating soil moisture status, plant physiology, and environmental conditions. There are few tools for measuring plant water status (water potential) in situ, presenting a critical barrier for the development of appropriate phenotyping (measurement) methods for crop development and modeling efforts aimed at understanding water transport in plants. Here, we present the development of an in situ, minimally-disruptive hydrogel nanoreporter (AquaDust) for measuring leaf water potential. The gel matrix responds to changes in water potential in its local environment by swelling; the distance between covalently linked dyes changes with the reconfiguration of the polymer, leading to changes in the emission spectrum via Fluorescence Resonance Energy Transfer (FRET). Upon infiltration into leaves, the nanoparticles localize within the apoplastic space in the mesophyll; they do not enter the cytoplast or the xylem. We characterize the physical basis for AquaDust’s response and demonstrate its function in intact maize (Zea mays L.) leaves as a reporter of leaf water potential. We use AquaDust to measure gradients of water potential along intact, actively transpiring leaves as a function of water status; the localized nature of the reporters allows us to define a hydraulic model that distinguishes resistances inside and outside the xylem. We also present field measurements with AquaDust through a full diurnal cycle to confirm the robustness of the technique and of our model. We conclude that AquaDust offers potential opportunities for high-throughput, field measurements and spatially resolved studies of water relations within plant tissues.

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