scholarly journals Soil moisture heterogeneity regulates water use in Populus nigra L. by altering root and xylem sap phytohormone concentrations

2020 ◽  
Vol 40 (6) ◽  
pp. 762-773 ◽  
Author(s):  
Jaime Puértolas ◽  
Marta Pardos ◽  
Carlos de Ollas ◽  
Alfonso Albacete ◽  
Ian C Dodd
Keyword(s):  
Soil Moisture ◽  
Water Use ◽  
Deficit Irrigation ◽  
Xylem Sap ◽  
Irrigation Scheduling ◽  
Populus Nigra ◽  
Soil Drying ◽  
Plant Water ◽  
Plant Water Use ◽  
Soil Moisture Heterogeneity

Abstract Soil moisture heterogeneity in the root zone is common both during the establishment of tree seedlings and in experiments aiming to impose semi-constant soil moisture deficits, but its effects on regulating plant water use compared with homogenous soil drying are not well known in trees. Pronounced vertical soil moisture heterogeneity was imposed on black poplar (Populus nigra L.) grown in soil columns by altering irrigation frequency, to test whether plant water use, hydraulic responses, root phytohormone concentrations and root xylem sap chemical composition differed between wet (well-watered, WW), and homogeneously (infrequent deficit irrigation, IDI) and heterogeneously dry soil (frequent deficit irrigation, FDI). At the same bulk soil water content, FDI plants had greater water use than IDI plants, probably because root abscisic acid (ABA) concentration was low in the upper wetter layer of FDI plants, which maintained root xylem sap ABA concentration at basal levels in contrast with IDI. Soil drying did not increase root xylem concentration of any other hormone. Nevertheless, plant-to-plant variation in xylem jasmonic acid (JA) concentration was negatively related to leaf stomatal conductance within WW and FDI plants. However, feeding detached leaves with high (1200 nM) JA concentrations via the transpiration stream decreased transpiration only marginally. Xylem pH and sulphate concentration decreased in FDI plants compared with well-watered plants. Frequent deficit irrigation increased root accumulation of the cytokinin trans-zeatin (tZ), especially in the dry lower layer, and of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), in the wet upper soil layer. Root hormone accumulation might explain the maintenance of high root hydraulic conductance and water use in FDI plants (similar to well-watered plants) compared with IDI plants. In irrigated tree crops, growers could vary irrigation scheduling to control water use by altering the hormone balance.

scholarly journals A Model for Irrigation Scheduling in Container-Grown Nursery Crops Utilizing Management Allowed Deficit (MAD)

1993 ◽  
Vol 11 (3) ◽  
pp. 115-118
Author(s):  
Douglas F. Welsh ◽  
Jayne M. Zajicek
Keyword(s):  
Plant Growth ◽  
Water Use ◽  
Irrigation Scheduling ◽  
Plant Performance ◽  
Plant Water ◽  
Irrigation Regimes ◽  
Plant Water Use ◽  
Moisture Deficit ◽  
Growing Medium ◽  
Nursery Crops

Abstract Plant growth and water use of container-grown Photinia × fraseri (Dress) were studied under varying irrigation regimes. Treatments were based on management allowed deficit (MAD) irrigation (including 0, 5, 10, 25, 50, 75 and 95% MAD), which links evapotranspiration (ET) and plant available moisture in determining irrigation schedules. Plant growth was maximized under 25% MAD irrigation. Plant performance and water use were significantly reduced as moisture deficit levels in the growing medium exceeded 50% under MAD irrigation of 50%, 75% and 95%. Plant performance also tended to decrease, but plant water use increased with lower MAD treatments (i.e., 0%, 5%, 10%). The research reported provides a model for nursery managers and researchers to use MAD irrigation in determining optimum irrigation regimes to meet plant water needs and maintain maximum plant performance.

Calcium Uptake and Whole-plant Water Use Influence Pod Calcium Concentration in Green Bean Plants

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 542d-542
Author(s):  
Kirk W. Pomper ◽  
Michael A. Grusak
Keyword(s):  
Water Use ◽  
Water Uptake ◽  
Xylem Sap ◽  
Green Bean ◽  
Plant Water ◽  
Plant Water Use ◽  
Whole Plant ◽  
Ca Uptake ◽  
Pod Development ◽  
Two Stages

Understanding the mechanisms that regulate xylem transport of calcium (Ca) to green bean pods could allow approaches to increase pod Ca concentrations and enhance the nutritional value of edible pods. Using the green bean cultivars `Hystyle' and `Labrador', that exhibit high and low pod Ca levels respectively, we wished to determine whether observed differences in Ca concentration of stem xylem-sap were related to differences in whole-plant water uptake and Ca import. Well-watered greenhouse-grown plants, selected at flowering and at two stages of pod development, were placed in a growth chamber at a constant light intensity. Pot weight loss was measured to determine whole-plant water use and stem xylem exudate was subsequently collected from the severed base of the shoot. `Hystyle' displayed 50% higher Ca concentration in exudate than `Labrador' during pod development. Labrador showed 35% greater total water transport through the stem than `Hystyle'. Additional plants were used to determine total, long-term Ca uptake. No significant differences in total Ca were seen between cultivars at the three harvest dates. With whole-plant Ca uptake being equivalent, the results suggest that higher water uptake in `Labrador' led to a dilution of Ca in the xylem stream and thus less total Ca was transported to developing pods, relative to that in `Hystyle'. These results reveal that green bean varieties with low whole-plant water use have the potential to yield edible pods with elevated Ca content.

scholarly journals Calcium Uptake and Whole-plant Water Use Influence Pod Calcium Concentration in Snap Bean Plants

2004 ◽  
Vol 129 (6) ◽  
pp. 890-895 ◽  
Author(s):  
Kirk W. Pomper ◽  
Michael A. Grusak
Keyword(s):  
Water Use ◽  
Water Uptake ◽  
Xylem Sap ◽  
Plant Water ◽  
Snap Bean ◽  
Plant Water Uptake ◽  
Plant Water Use ◽  
Whole Plant ◽  
Pod Development ◽  
Two Stages

Understanding the mechanisms that regulate xylem transport of calcium (Ca) to snap bean (Phaseolus vulgaris L.) pods could allow approaches to increase pod Ca concentration and enhance the nutritional value of edible pods. Using the snap bean cultivars Hystyle and Labrador, which exhibit high and low pod Ca levels, respectively, we wished to determine whether there were differences between the two cultivars in stem xylem-sap Ca concentration and whether any differences in sap Ca concentration were related to differences in whole-plant water uptake or Ca import between the cultivars. Well-watered greenhouse-grown plants were placed in a growth chamber at a constant light intensity for an equilibration period. Pot weight loss was measured to determine whole-plant water use and stem xylem exudate was subsequently collected from the severed base of the shoot at flowering and at two stages of pod development. `Hystyle' displayed an exudate Ca concentration that was 50% higher than `Labrador' during pod development. `Labrador' showed 35% greater total water transport through the stem than `Hystyle'. `Labrador' plants also showed a significantly larger leaf area than `Hystyle' plants. Additional plants were used to determine total, long-term Ca influx. No difference was observed between cultivars in total Ca influx into the aerial portion of the plant. With whole-shoot Ca influx being equivalent and pod transpiration rate identical in the two cultivars, our results suggest that the higher whole-plant water uptake in `Labrador' led to a dilution of Ca concentration in the xylem stream and thus less total Ca was transported to developing pods, relative to that in `Hystyle'. Increased transpiration efficiency, enhanced root uptake of Ca, or reduced Ca sequestration in the xylem pathway of the stem could lead to an enhancement in pod Ca concentration in future cultivars of snap bean.

The effect of deficit irrigation on seasonal variations of plant water use in Olea europaea L.

2005 ◽  
Vol 273 (1-2) ◽  
pp. 139-155 ◽  
Author(s):  
Roberto Tognetti ◽  
Riccardo d’Andria ◽  
Giovanni Morelli ◽  
Arturo Alvino
Keyword(s):  
Water Use ◽  
Seasonal Variations ◽  
Olea Europaea ◽  
Deficit Irrigation ◽  
Plant Water ◽  
Olea Europaea L ◽  
Plant Water Use ◽  
Olea Europaéa

scholarly journals Influence of Climatic Variables on Whole-plant Water use of Cocoa under Limited Soil Moisture Condition

2019 ◽  
pp. 1-8
Author(s):  
Femi S. Omotayo ◽  
Philip G. Oguntunde ◽  
Ayorinde A. Olufayo
Keyword(s):  
Soil Moisture ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Correlation Coefficient ◽  
Water Use ◽  
Vapour Pressure ◽  
Plant Water ◽  
Plant Water Use ◽  
Whole Plant ◽  
Cocoa Plantation

Cocoa (Theobroma cacao L.) is a cash crop that is cultivated in many tropical regions of the world and is highly productive under favourable climatic conditions. Cocao, being originally an under storey tree of rainforests in tropical America, is traditionally cultivated below the canopy of shade trees. This study is carried out to establish the influence of climatic variables on whole-plant water use of cocoa under limited soil moisture conditions. An experimental plot was made in an even – aged 54 years old cocoa plantation which was demarcated while Water use measurement carried out for 20 consecutive days at the center of the cocoa plantation field at the Federal University of Technology, Akure using the temperature difference method (Sap flow meter). The results of evaporation rate and water consumed by crops led to decrease in soil water in the monitored root zone from 0.049 to 0.015 m3 m-3. Solar radiation reached a high value of 1002.37 Wm-2, with day time average of 238.02 Wm-2. Temperature ranges between 16.41 and 34.19ºC with a daily average of about 24.39ºC. Relative humidity varied from 98.60% to less than 32.37% with daily mean of around 74.90%. Vapour pressure varied from 0.01 to 2.87 kpa. The day time wind speeds rarely exceed 5.2 ms-1 while the daily averages were generally around 1.09 ms-1.  The results also show that transpiration, (Ec) is mostly influenced by solar radiation with a correlation coefficient of 0.71 while other variable like temperature, Vapour pressure deficit, and Relative humidity has correlation coefficient of 0.62, 0.50 and 0.58 respectively. The total amount of rainfall during the experiment was 38.9 mm. This shows that solar radiation has greater influence on the transpiration of the cocoa plant than other variables in the study area.

scholarly journals Plant Water Use Differs among Three Mature Highbush Blueberry Cultivars

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1127C-1127 ◽  
Author(s):  
Wei Qiang Yang ◽  
David Bryla ◽  
Bernadine Strik
Keyword(s):  
Water Use ◽  
Fruit Development ◽  
Developmental Stages ◽  
Development Stage ◽  
Irrigation Scheduling ◽  
Highbush Blueberry ◽  
Plant Water ◽  
Plant Water Use ◽  
Fruit Maturity ◽  
Crop Coefficients

The water use of three mature highbush blueberry cultivars was determined during the growing season by using TDR technology. A combination of four buriable TDR waveguides at 6-, 12-, 18-, and 24-inch depth and two surface waveguides 6- and 18-inch length were installed in a 60-acre commercial `Bluejay', `Bluecrop', and `Jersey' blueberry field with four replications for each cultivar. The reference evapotranspiration (ETo) was obtained for each cultivar from three weather stations located in the vicinity of replicated waveguides. Soil moisture data were collected every 3-5 days from April to the end of September. The average daily crop evapotranspiration (ETc) was significantly different at different plant developmental stages among three cultivars; the highest daily plant water use was during the fruit development stage for all three cultivars. The crop ETc for `Bluejay' and `Elliott' can be as high as 0.35 inches per day and average 1.5 to 2 inches per week during the summer. The estimated crop coefficients at bloom, fruit development, harvest, and postharvest are 0.90, 1.51, 1.05, and 1.05 for `Bluejay'; 0.84, 1.11, 0.99, and 1.23 for `Bluecrop'; and 0.94, 1.30, 1.39, and 1.17 for `Jersey', respectively. The peak water use coincides well with the advancement of fruit maturity, suggesting irrigation scheduling should differ among early, mid, and later season highbush blueberry cultivars.

Hydraulic and chemical signalling in the regulation of stomatal conductance and plant water use in field grapevines growing under deficit irrigation

2008 ◽  
Vol 35 (7) ◽  
pp. 565 ◽  
Author(s):  
M. Lucília Rodrigues ◽  
Tiago P. Santos ◽  
Ana P. Rodrigues ◽  
Claudia R. de Souza ◽  
Carlos M. Lopes ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Water Availability ◽  
Dominant Role ◽  
Xylem Sap ◽  
Soil Water Availability ◽  
Vitis Vinifera L ◽  
Plant Water ◽  
Chemical Signalling ◽  
Plant Water Use

Effects of irrigation strategies on stomata and plant water use were studied in field-grown grapevines (Vitis vinifera L.). We assessed the importance of root-derived chemical signals vs. hydraulic signalling in stomatal regulation. The experiment included two treatments with the same water added to the soil (50% ETc) applied either to the whole root system (DI) or to half of the roots, alternating irrigation side every 15 days (PRD). Well-watered plants (FI) (100% ETc) and non-irrigated grapevines (NI) were also studied. Partial stomata closure occurred in both PRD and DI plants. [ABA] of xylem sap remained constant during the day and was maintained throughout the season, with higher values in NI plants. Xylem sap pH was not affected by soil water availability. A positive correlation between ψpd and maximum g s was found, indicating that grapevine stomata strongly respond to plant water status. In contrast, ABA did not explain stomatal control at veraison. At mid-ripening g s was significantly correlated with ABA, apparently interacting with the rise in xylem sap pH. Therefore, our data suggest that hydraulic feedback and feed-forward root-to-shoot chemical signalling mechanisms might be involved in the control of stomata in response to decreased soil water availability, hydraulic signals playing the dominant role.

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