scholarly journals SOIL WATER DEFICIT EFFECTS ON PLANT WATER RELATIONS AND LEAF GROWTH OF CUCUMBER

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 596c-596
Author(s):  
Jeffrey Melkonian ◽  
David W. Wolfe
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Leaf Growth ◽  
Soil Water Potential ◽  
Conclusive Evidence ◽  
Soil Water Deficit ◽  
Leaf Elongation ◽  
Relative Water ◽  
And Control

Cucumber (Cucumis sativus L. cv. Marketmore 80) plants were exposed to a soil water deficit and subsequently rewatered. Maximum stress intensity was -1.5 MPa midday leaf water potential compared to -0.6 to -0.8 MPa in the well watered control, eight days after withholding water. Midday stomatal conductance {ks), leaf turgor potential and water potential decreased in the stress treatment compared to the control beginning at the first sampling, two days after withholding water. The decrease in all three was approximately linear with time over the stress. Decreased leaf elongation was observed at the second sampling, three days after the initial decline in ks and five days after withholding water. At similar relative water content {RWC), osmotic potentials of the stress and control treatments were the same throughout most of the stress. Further, there was no difference in osmotic potential, at the same RWC, between the stress and control treatments 12 - 16 hours after rewatering. Split-root experiments were also conducted to examine a possible role of a non-hydraulic signal from roots in drying soil in the regulation of ks and leaf elongation in cucumber. No conclusive evidence of a signal was found despite significant decreases in soil water potential of one-half of the root system of the stress plants. However, fluctuating vapor pressure gradients (vpg) may have obscured evidence of a signal.

Soybean Irrigation Initiation in Mississippi: Yield, Soil Moisture, and Economic Response

2019 ◽  
Vol 35 (1) ◽  
pp. 39-50
Author(s):  
H. C. Pringle, III ◽  
L. L. Falconer ◽  
D. K. Fisher ◽  
L. J. Krutz
Keyword(s):  
Soil Moisture ◽  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Mississippi Delta ◽  
Soil Water Potential ◽  
Irrigation Scheduling ◽  
Silty Clay ◽  
Soil Water Deficit ◽  
Soybean Yield

Abstract. Irrigated acreage is expanding and groundwater supplies are decreasing in the Mississippi Delta. Efficient irrigation scheduling of soybean [ (L.) Merr] will aid in conservation efforts to sustain groundwater resources. The objective of this study was to develop irrigation initiation recommendations for soybean grown on Mississippi Delta soils. Field studies were conducted on a deep silty clay (SiC) in 2012, 2013, 2014, and 2015 and on a deep silty clay loam (SiCL) and deep silt loam (SiL) or loam (L) soil in 2013, 2014, and 2015. Irrigation was initiated multiple times during the growing season and soybean yield and net return were determined to evaluate the effectiveness of each initiation timing. Growth stage, soil water potential (SWP), and soil water deficit (SWD) were compared at these initiation timings to determine which parameter or combination of parameters consistently predicted the resulting greatest yields and net returns. Stress conditions that reduce yield can occur at any time from late vegetative stages to full seed on these deep soils. The wide range of trigger values found for SWP and SWD to increase yields in different years emphasizes the complexity of irrigation scheduling. Monitoring soil moisture by itself or use of a single trigger value is not sufficient to optimize irrigation scheduling to maximize soybean yield with the least amount of water every year on these soils. Monitoring one or more parameters (e.g., leaf water potential, canopy temperature, air temperature, humidity, solar radiation, and wind) is needed in conjunction with soil moisture to directly or indirectly quantify the abiotic stresses on the plant to better define when a yield reducing stress is occurring. Keywords: Irrigation initiation, Irrigation scheduling, Soil water deficit, Soil water potential, Soybean, Water conservation.

A basis for improved soil and water management for irrigated pastures in northern Victoria

1988 ◽  
Vol 28 (3) ◽  
pp. 315 ◽  
Author(s):  
SJ Blaikie ◽  
FM Martin ◽  
WK Mason ◽  
DJ Connor
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
White Clover ◽  
Soil Profile ◽  
Leaf Water ◽  
Individual Species ◽  
Soil Water Deficit ◽  
Leaf Elongation

The water relations of white clover and paspalum as monocultures and components of a mixed pasture were studied on a normal and a modified soil profile during the interval between 2 successive irrigations. Responses of individual species were similar in monocultures and mixed pastures. On the normal profile white clover was the first species to react to soil water deficit when the rate of leaf elongation fell by 33% to about 10 mm/day after 30 mm of cumulative evaporation minus rainfall (E - R). This was followed by a reduction in dawn and midday leaf water potential at around 50 mm E - R. After 65 mm E - R, leaf elongation had ceased. In contrast, paspalum showed no signs of water shortage until 70-80 mm E - R. At this stage both the rate of leaf elongation and midday leaf water potential fell. After 90 mm E - R the dawn leaf water potential fell and by 120 mm E - R leaf elongation was negligible. Modification of the profile increased soil water availability by allowing more extraction of water at depth in the profile. This delayed the onset of water stress by about 40 mm E - R in both species. These observations show that the common irrigation interval of 60-90 mm E - R in northern Victoria is likely to restrict pasture yields because it causes a period of soil water deficit stress, especially for white clover, and the development of leaf area is impeded, increasing the time taken for canopies to recover maximum productivity after grazing. To overcome these limitations farmers will have to water more frequently or modify the soil profile to provide pastures with a better water supply.

scholarly journals Water status and gas exchange of umbu plants (Spondias tuberosa Arr. Cam.) propagated by seeds and stem cuttings

2007 ◽  
Vol 29 (2) ◽  
pp. 355-358 ◽  
Author(s):  
José Moacir Pinheiro Lima Filho
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Leaf Gas Exchange ◽  
Leaf Water ◽  
Soil Water Deficit ◽  
Stem Cuttings

The experiment was carried out at the Embrapa Semi-Árido, Petrolina-PE, Brazil, in order to study the physiological responses of umbu plants propagated by seeds and by stem cuttings under water stress conditions, based on leaf water potential and gas exchange measurements. Data were collected in one-year plants established in pots containing 30 kg of a sandy soil and submitted to twenty-day progressive soil water deficit. The evaluations were based on leaf water potential and gas exchange data collection using psychrometric chambers and a portable infra-red gas analyzer, respectively. Plants propagated by seeds maintained a significantly higher water potential, stomatal conductance, transpiration and photosynthesis under decreasing soil water availability. However, plants propagated by stem cuttings were unable to maintain a favorable internal water balance, reflecting negatively on stomatal conductance and leaf gas exchange. This fact is probably because umbu plants propagated by stem cuttings are not prone to formation of root tubers which are reservoirs for water and solutes. Thus, the establishing of umbu plants propagated by stem cuttings must be avoided in areas subjected to soil water deficit.

scholarly journals Eucalyptus sp. seedling response to potassium fertilization and soil water.

2008 ◽  
Vol 18 (1) ◽  
pp. 47 ◽  
Author(s):  
Paulo César Teixeira ◽  
José Leonardo Moraes Gonçalves ◽  
José Carlos Arthur Junior ◽  
Cleci Dezordi
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Leaf Area ◽  
Water Deficit ◽  
Water Relations ◽  
Transpiration Rate ◽  
Dry Matter ◽  
Soil Water Potential ◽  
Eucalyptus Grandis ◽  
Eucalyptus Urophylla

A considerable portion of Brazil‘s commercial eucalypt plantations is located in areas subjected to periods of water deficit and grown in soils with low natural fertility, particularly poor in potassium. Potassium is influential in controlling water relations of plants. The objective of this study was to verify the influence of potassium fertilization and soil water potential (Ψw) on the dry matter production and on water relations of eucalypt seedlings grown under greenhouse conditions. The experimental units were arranged in 4x4x2 randomized blocks factorial design, as follow: four species of Eucalyptus (Eucalyptus grandis, Eucalyptus urophylla, Eucalyptus camaldulensis and hybrid Eucalyptus grandis x Eucalyptus urophylla), four dosages of K (0, 50, 100 and 200 mg dm-3) and two soil water potentials (-0.01MPa and -0.1 MPa). Plastic containers with 15 cm diameter and 18 cm height, with Styrofoam base, containing 3.0 dm3 of soil and two plants per container were used. Soil water potential was kept at -0.01MPa for 40 days after seeding. Afterward, the experimental units were divided into two groups: in one group the potential was kept at -0.01MPa, and in the other one, at -0.10 MPa. Soil water potential was controlled gravimetrically twice a day with water replacement until the desired potential was reestablished. A week before harvesting, the leaf water potential (Ψ), the photosynthetic rate (A), the stomatal conductance (gs) and the transpiration rate were evaluated. The last week before harvesting, the mass of the containers was recorded daily before watering to determine the consumption of water by the plants. After harvesting, total dry matter and leaf area were evaluated. The data were submitted to analysis of variance, to Tukey's tests and regression analyses. The application of K influenced A, gs and the transpiration rate. Plants deficient in K showed lower A and higher gs and transpiration rates. There were no statistical differences in A, gs and transpiration rates in plants with and without water deficit. The addition of K reduced the consumption of water per unit of leaf area and, in general, plants submitted to water deficit presented a lower consumption of water.

scholarly journals Transpiration and leaf growth of potato clones in response to soil water deficit

2014 ◽  
Vol 71 (2) ◽  
pp. 96-104 ◽  
Author(s):  
André Trevisan de Souza ◽  
Nereu Augusto Streck ◽  
Arno Bernardo Heldwein ◽  
Dilson Antonio Bisognin ◽  
José Eduardo Minussi Winck ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Leaf Growth ◽  
Soil Water Deficit

Transpiration and leaf growth of gladiolus in response to soil water deficit

2021 ◽  
Vol 283 ◽  
pp. 110031
Author(s):  
Camila Coelho Becker ◽  
Nereu Augusto Streck ◽  
Paulo Ivonir Gubiani ◽  
Lilian Osmari Uhlmann ◽  
Josana Andreia Langner ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Leaf Growth ◽  
Soil Water Deficit
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