Dec 29, 2015
• ENH 102. Physiological Principles in Environmental Horticulture (4)
• Lecture—3 hours; discussion—1 hour. Prerequisite: Biological Sciences 1C. Physiological principles and processes essential to floriculture, nursery crop production, turfculture and landscape horticulture. Emphasis on the control of vegetative and reproductive development for a broad species range in greenhouse and extensive landscape environments. GE credit: SE.—I. (I.) Burger Gilbert
Who am I?
• Matthew Gilbert • Department of Plant Sciences
– 2314 Plant and Environmental Sciences Building – [email protected] – Office Hours:
• Mondays 2pm-4:30pm (email me otherwise) • PES 2314
Who am I?
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What is Environmental Horticulture?
• Department of Plant Biology – Basic plant research (?focusing on small scales?)
• Department of Plant Sciences – Agronomy and Vegetable Crops – Pomology – Rangeland Science – Environmental Horticulture
Goals for the Course • To provide students with an integrative overview of
major physiological plant processes spanning the biochemical, cellular, tissue, organ and whole plant levels of organization.
• To build a physiological basis upon which students can understand the effects on and responses of plants to their environment.
“Horticulturists know how to grow plants; physiologists know how plants grow.” • To provide you with (intellectual) tools to observe
and understand the plants that surround you.
http://berxblog.blogspot.com/2012/03/creating-my-mobile-toolbox-for-windows.html
Goals for the Course
• Back of the envelope calculations • Critical thought using plant physiology • Critical reading of scientific papers
http://en.wikipedia.org/wiki/File:HouseCastSeason1.jpg
http://12160.info/group/marijuanagodsplant/forum/topics/famous-stoners-throughout-history
http://en.wikipedia.org/wiki/File:Goldman_Sachs.svg
http://en.wikipedia.org/wiki/File:Orchid_plants.jpg
Introduction
Plant Physiology?
• An integrative science – Biology – Chemistry – Physics – Math – Anatomy – Morphology
Introduction
Plant Physiology?
• The science concerned with processes and functions
• Processes – Photosynthesis – Respiration – Ion uptake – Translocation – Transpiration – Flowering – Seed formation
Introduction
Unifying Concepts • Importance of water • Membranes • Energy
– Chemical potential • Photosynthesis
– ATP, NADPH • Respiration
– Water potential • Internal control mechanisms of plants • Environmental responses of plants • Mechanisms of adaptability
Introduction
Unifying Principles of Plants • Convert light energy into chemical energy
– Photosynthesis • Non-motile • Must evolve or adapt or else • Have cell walls
– Structural reinforcement • Continuously uptake, transport and lose water
– Transpiration – Evaporation
• Developed means of nutrient and photosynthate translocation
He’s forgotten genetics!
Structure Enzymes/ protein
Resource cycles
H2O NADPH
Genes
http://www.thehistoryblog.com/wp-content/uploads/2013/05/Watson-Crick-DNA-model.jpg
Course format
• Lectures (22 topics) • No lab (video’s + demonstrations + examples) • Evaluations:
– One final exam (150) – One (two?) midterms (100) – Group discussion exercises (125) – Arboretum tour (25) – One minute evaluations (evaluation of progress)
• 1 – Introduction and Environment • 2 – Anatomy • 3 – Membranes • 4 – Bioenergetics • 5- Photosynthesis – Light dependent
reactions • 6- Photosynthesis – Light
independent reactions • 7 – Factors affecting photosynthesis • 8 – Respiration • 9 – Water relations • 10- SPAC • 11- Transpiration • 12- Water stress
• 13- Translocation • 14 – Mineral nutrition • 15 – Uptake and assimilation • 16 – Nutrient deficiency • 17 – Growth • 18 – Differentiation and
Development • 19 – Growth regulators: Auxin,
Cytokinin, Gibberellin, Growth inhibitors, Ethylene
• 20 – Developmental physiology • 21 – Postharvest • 22 – Stress physiology
Reference material • No textbook – so will post lecture slides on
Smartsite • Will post websites at lectures • Taiz and Zeiger - on reserve, any edition is fine • Alternatives abound:
– Salisbury and Ross Plant Physiology – Hopkins and Huner Introduction to Plant Physiology
• If you see a career as an plant physiologist, then these graduate student-level books are useful:
– Lambers et al. Plant Physiological Ecology (PDF available on UCD library website)
– Nobel Physicochemical and Environmental Plant Physiology (serious physics)
Any questions?
Why study the environment, when this is a Plant Physiology course?
• What is a plant’s environment? • Radiation • Temperature • Humidity • Wind • Atmosphere
Temperature
• oC, F or K • Temperature affects:
– Growth and development – Water loss – Photosynthesis and enzymatic processes
• Zwieniecki’s First Law: Temperature affects everything e.g. PV=nRT
Relative humidity • RH is a function of vapor pressure, temperature and atmospheric
pressure (~altitude)
• 0-100% relative humidity of air • 100% is saturation at which condensation occurs • RH=100*ea/esat
– ea = pressure of H2O vapor – esat = saturation pressure of H2O vapor
• But esat = f(Tair) • Is relative humidity very useful?
• http://en.wikipedia.org/wiki/Relative_humidity
http://en.wikipedia.org/wiki/File: Atmosphere_gas_proportions.svg
RH=ea/esat*100
Dry bulb, wet bulb and dew point temperatures • Dry bulb temperature – (shielded) air temperature of dry
thermometer – used in weather reports
• Wet bulb temperature – temperature of thermometer when cooled by evaporating water – used to calculate humidity, or used to evaluate cooling potential of
evaporation
• Dew point temperature or saturation temperature – temperature of air or substance that results in condensation of water vapor – used to control temperatures to prevent or cause condensation
• Great and simple explanation: http://www.ianrpubs.unl.edu/pages/publicationD.jsp?publicationId=1000
• Measurement: using electric RH and Tair meter • Sling psychrometer: http://www.youtube.com/watch?v=Sxm6yq268Bc
ftp://ftp.licor.com/perm/env/LI-610/Manual/610card.pdf
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Wat
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Pa)
Air temperature (oC)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
Relative humidty
Water vapor pressure and dewpoint estimation at sea-level:1) Saturated vapor pressure -where air temperature meets 100%RH curve 2) Water vapor pressure - find intersection of air temperature line and and RH curve, read vapor pressure off y-axis 3) Dewpoint temperature -calculate vapor pressure as in (2) find intersection with 100%RH curve.
A good reference:
Vapor pressure deficit From FAO56
Leaf water loss is roughly proportional to the difference in the atmospheric partial pressure of water in the leaf and outside the leaf
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0 5 10 15 20 25 30 35 40 45
Wat
er v
apor
pre
ssur
e (k
Pa)
Air temperature (oC)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
Relative humidty
Water vapor pressure and dewpoint estimation at sea-level:1) Saturated vapor pressure -where air temperature meets 100%RH curve 2) Water vapor pressure - find intersection of air temperature line and and RH curve, read vapor pressure off y-axis 3) Dewpoint temperature -calculate vapor pressure as in (2) find intersection with 100%RH curve.
VPD = esat(@Tleaf)-ea(@Tair) 1.7 2.5
VPD 9AM = 2.5-1.7 = 0.8 kPa
Vapor pressure deficit From FAO56
Leaf water loss is roughly proportional to the difference in the atmospheric partial pressure of water in the leaf and outside the leaf
0
1
2
3
4
5
6
7
8
9
10
0 5 10 15 20 25 30 35 40 45
Wat
er v
apor
pre
ssur
e (k
Pa)
Air temperature (oC)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
Relative humidty
Water vapor pressure and dewpoint estimation at sea-level:1) Saturated vapor pressure -where air temperature meets 100%RH curve 2) Water vapor pressure - find intersection of air temperature line and and RH curve, read vapor pressure off y-axis 3) Dewpoint temperature -calculate vapor pressure as in (2) find intersection with 100%RH curve.
VPD = esat(@Tleaf)-ea(@Tair)
4.9
1.7 2.5
VPD 9AM = 2.5-1.7 = 0.8 kPa VPD 3PM = 4.9-1.7 =
From: http://en.wikipedia.org/wiki/Psychrometrics
Wind
• http://en.wikipedia.org/wiki/Beaufort_scale • Growth chambers/greenhouses have circulation • Wind couples things (leaves) with air
– enhances water loss – changes temperature
What is light?
http://en.wikipedia.org/wiki/File:Linear_visible_spectrum.svg
What is light?
Solar radiation: W m-2 = J s-1 m-2
Wavelength: 250nm – 2.5µm Intensity: full sunlight 1000 W m-2
http://en.wikipedia.org/wiki/File:Linear_visible_spectrum.svg
Light: Lux (weighted according to human perception) Wavelength: 380nm – 750nm Intensity: full sunlight 100000 lux
Power or energy
Light for plants
http://en.wikipedia.org/wiki/File:Par_action_spectrum.gif
PAR, PPF and PPFD: µmol * m-2 s-1
Wavelength: 400nm – 700nm Intensity: full sunlight 2000 µmol m-2 s-1
* That is micro mols of photosynthetically active photons per m2 per s Why express PAR as a quantum unit rather than energy (W m-2)?
Photosynthetically Active Radiation, Photosynthetic Photon Flux and Photosynthetic Photon Flux Density
http://en.wikipedia.org/wiki/File:Linear_visible_spectrum.svg
http://en.wikipedia.org/wiki/File:Linear_visible_spectrum.svg
Which is the best artificial light source for growing plants?
Source: LICOR6400XT manual
700nm - > beyond here lies heat UV <- 400nm
Atmosphere
• Sea level: 101.35 kPa • O2 20.9% ~21kPa • H2O 0-5% ~ 0-5kPa • CO2 0.04% ~ 40Pa ~ 400ppm
• O3 low
• pollution
http://en.wikipedia.org/wiki/File: Atmosphere_gas_proportions.svg
What factors influence plant water loss?
• Environmental: – Solar radiation – Wind – VPD (RH and temperature)
• Plant characteristics – Leaf and canopy shape – How wide the stomata are open and their density
From FAO56
ETo = reference evapotranspiration
Landscape coefficient/crop coefienct
ETo = reference evapotranspiration
• Penman-Monteith equation:
• Main publication: FAO56 http://www.kimberly.uidaho.edu/ref-et/fao56.pdf
From FAO56
Wind speed
ETo applied to landscapes
http://www.water.ca.gov/wateruseefficiency/docs/wucols00.pdf
http://en.wikipedia.org/wiki/File:Lysimeter_g1.svg http://dateline.ucdavis.edu/071996/071996no1.html
http://wwwcimis.water.ca.gov/cimis/frontMapView.do?urlImg=eto
Exercise #1
http://crf.ucdavis.edu/virtual-tour /conviron-growth-chamber/
ftp://ftp.licor.com/perm/env/LI-610/Manual/610card.pdf
0
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3
4
5
6
7
8
9
10
0 5 10 15 20 25 30 35 40 45
Wat
er v
apor
pre
ssur
e (k
Pa)
Air temperature (oC)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
Relative humidty
Water vapor pressure and dewpoint estimation at sea-level:1) Saturated vapor pressure -where air temperature meets 100%RH curve 2) Water vapor pressure - find intersection of air temperature line and and RH curve, read vapor pressure off y-axis 3) Dewpoint temperature -calculate vapor pressure as in (2) find intersection with 100%RH curve.
A good reference: