Methods of Studying Plant Water Relations

Psychrometric Methods.- 1.4.2.5 Refractometric Method.- 1.4.3 Deformation Method for Measuring Osmotic Potential of Tissues.- 1.5 Determination of Turgor Pressure (Pressure Potential).- 1.5.1 Introduction.- 1.5.2 Calculations of Pressure Potential.- 1.5.3 Direct Measurements of Pressure Potential.- 1.5.4 Indirect Methods for Determination of Pressure Potential.- 1.6 Matric Potential, "Bound", "Free" and "Mobile" Water.- 1.6.1 Introduction.- 1.6.2 Determination of Matric Potential.- 1.6.3 Determinations of "Free" and "Bound" Water.- 1.6.3.1 Dilatometric Method.- 1.6.3.2 Refractometric Method.- 1.6.3.3 Cryoscopic Method.- 1.6.3.4 Cobalt Chloride Method.- 1.6.4 Determination of "Mobile" Water.- 2 Water Content.- 2.1 Direct Methods of Water Content.- 2.1.1 Determination of the Water Content by Drying.- 2.1.2 Chemical Determination of Water by Titration.- 2.1.3 Other Methods.- Determination of Water in Microscopic Sections.- Determination of Water by Distillation with Toluene.- 2.2 Indirect Methods of Water Content.- 2.2.1 Measurement of the Absorption of Radioactive Radiation.- Determination of the Water Content of Leaves.- Determination of the Water Content of Thicker and Denser Organs.- Determination of the Water Content of a Plant Community.- 2.2.2 Measurement of Dielectric Constant (Capacitance) and Related Procedures.- 2.2.3 Measurement of Electrical Conductivity of the Tissue.- 2.2.4 Other Methods.- 2.3 Determination of the Water Content of Cell.- 2.4 Root Bridge Method.- 2.5 Water Saturation Deficit (Relative Water Content.- 2.5.1 Characteristics of These and Analogous Terms.- 2.5.2 Review and Discussion of the Methods which Have Been Used.- 2.5.3 Practical Hints.- 2.5.4 Determination of Harmful Water Saturation.- 2.5.4.1 Basic Terms.- 2.5.4.2 Techniques.- 3 Water Exchange between Plant Roots and Soil.- 3.1 Availability of Soil Water.- 3.1.1 Introduction.- 3.1.1.1 Static Availability of Soil Water.- 3.1.1.2 Dynamic Availability of Soil Water.- 3.1.2 Brief Review of Methods Used to Determine the Soil Water Content.- 3.1.3 Determination of Static Availability of Soil Water.- 3.1.3.1. Determination of Soil Water Potential.- 3.1.3.2 Determination of Matric Potential of Soil.- Soil Tensiometers.- Osmotic Tensiometer.- Resistance Block Method.- Other Methods for Matric Potential Estimation.- Suction Plate and Pressure Membrane.- 3.1.3.3 Determination of the Osmotic Potential of Soil Solution.- 3.1.4 Estimation of Dynamic Availability of Soil Water.- 3.1.4.1 Permanent Wilting Percentage.- Techniques Used to Determine P.W.P.- Examples of Standardized Procedures Used by Different Authors.- 3.1.5 Experimental Control of Soil Moisture.- 3.2 Determination of the Water Potential of.- 3.3 Determination of Water Absorption by.- 3.3.1 Potometric Determination of Rate of Water Absorption by a Complete Root System.- 3.3.2 Micropotometric Determination of the Differences in the Rate of Water Absorption in the Various Parts of a Single Root.- 3.3.3 Potometric Measurement of Experimentally Induced Water Uptake.- 3.3.4 Potometric Determination of Water Balance.- 3.3.5 Soil Potometers.- 3.4 Xylem Sap Exudation from Excised Roots and Root Systems.- 3.4.1 Introduction.- 3.4.2 Measurement of Sap Volume.- 3.4.3 Other Experimental Techniques.- 3.4.4 Determination of Root Pressure.- 3.4.5 Mathematical Models of Sap Exudation.- 4 Liquid Water Movement in Plants.- 4.1 Determination of Hydraulic Conductivity (Water Permeability) of Cytoplasm, Cell Membrane and Parenchymatous Tissues.- 4.1.1 "Osmotic" Measurements.- 4.1.2 "Pressure" Measurements.- 4.1.3 "Diffusion" Measurements.- 4.2 Measurements of the Velocity of Water Movement in Xylem.- 4.2.1 Heat Pulse Methods.- Measuring Procedures.- Heating Devices.- Temperature Sensing Elements.- 4.2.2 Radioactive Tracer Method.- 4.2.3 Magnetohydrodynamic Method.- 4.3 Measurements of the Volume Flux of Water in Xylem Vessels.- 4.3.1 Heat Balance Methods.- 4.3.2 Radioactive Tracer Methods.- 5 Water Exchange between Plant and Atmosphere.- 5.1 Introduction.- 5.2 Air Humidity.- 5.2.1 Expressions for Air Humidity and a Review of Methods Used for its Determination.- 5.2.2 Control of Air Humidity.- 5.3 Water Absorption by Aerial Parts of Plants.- 5.3.1 Introduction.- 5.3.2 Review of Methods Used to Measure Dew.- 5.3.3 Determination of Water Absorption by Aerial Parts.- 5.4 Ecological Factors in Transpiration.- 5.4.1 Evaporimeters. Equivalent Evaporation Power.- 5.4.2 Relative Transpiration.- 5.5 Transpiration.- 5.5.1 Introduction.- 5.5.2 Measurement of Instantaneous Transpiration Rate.- 5.5.2.1 Method of Short-term Weighing of Detached Parts of Plants.- 5.5.2.2 Short-term Gasometric Measurements.- 5.5.3 Continuous Measurement of the Transpiration Rate of Intact Plants.- 5.5.3.1 Gasometric Methods.- Gasometric Systems.- Transpiration Chambers.- Other Components of Gasometric Systems.- Infrared Analysers.- Psychrometric Methods.- Lithium Chloride and Other Resistance Hygrometers.- Dew-point Hygrometers.- Corona Hygrometer.- Microwave Hygrometer.- List of Manufacturers of Different Commercial Types of Hygrometers.- Thermoflux.- Gravimetric Absorption Methods.- 5.5.3.2 Gravimetric Methods.- 5.5.4 Measurement of Integrated Transpiration.- 5.5.5 Water Loss by Detached Leaves.- 5.5.6 Determination of Transpiration Resistance.- 5.5.6.1 Introduction.- 5.5.6.2 Calculation of Transpiration Resistances from Measurements of Steady State Transpiration Rate.- 5.5.6.3 Calculation of Transpiration Resistance from Leaf Energy Balance.- 5.5.6.4 Cobalt Chloride Paper Method.- 5.5.7 Transpiration Ratio and Productivity of Transpiration.- 5.5.8 Calculations of the Transpiration Rate and Examples.- 5.6 Stomata.- 5.6.1 Introduction.- 5.6.2 Frequency, Size and Shape of Stomata.- 5.6.3 Measurement of Stomatal Aperture.- 5.6.3.1 Direct Observation.- 5.6.3.2 Microrelief (Replica) Methods.- 5.6.3.3 Infiltration Methods.- 5.6.4 Porometry.- 5.6.4.1 Water Vapour Diffusion Porometers.- Unventilated Porometers.- Calibration of Unventilated Porometers.- Ventilated Porometers.- Calibration of Ventilated Porometers.- Steady State Diffusion Porometers.- 5.6.4.2 Diffusion Porometers Using Other Gases.- 5.6.4.3 Mass Flow Porometers.- Flow Rate Porometers.- Resistance Porometers.- Pressure - drop Porometers.- 5.7 Guttation.- 6 Table Appendix.- 6.1 Pertinent Physical Values, their Symbols and Units.- 6.2 Prefixes for Units.- 6.3 Some Mathematical Symbols.- 6.4 Some Physical Properties of Liquid Water.- 6.5 Some Physical Properties of Water Vapour.- 6.6 Absolute Air Humidity at Various Relative Air Humidities and Air Temperatures [Range -10 to 40°C and 10 to 100% r. h.].- 6.7 Absolute Air Humidity at Various Relative Air Humidities and Air Temperatures [Detailed Tables, Range 15 to 30°C and 40 to 100% r.h.].- 7 References.- Author Index.