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Environmental Plant Physiology Lecture

Environmental Plant Physiology provides a link between the cellular and biochemical analysis in plant physiology and more applied aspects of plant growth. Environmental Plant Physiologists examine the ways that physiological processes are integrated to cause whole plant responses in communities. The subject matter is related to Plant Ecology and Stress Physiology. The basic concepts and approaches are applicable to all types of plants, from petunias to potatoes to plums; grown in pots or in soil, in greenhouses or in the field.

Emphasis will be placed on the relationship between environmental parameters (radiation, temperature, water, nutrients), and their effect on physiological processes (photosynthesis, respiration), and plant responses (leaf expansion, partitioning of dry mass, water status, and transpiration). We will examine the integration of these plant responses into models that help to better understand and predict growth and yield.


12 Course Overview: Quantifying Responses
14 Leaf Energy Balance: Types of Radiation
19 Leaf Energy Balance: Radiation absorption
21 Leaf Energy Balance: Transpiration
26 Energy balance: Conduction and convection
28 Plant Growth Analysis: Individual Plants

02 Plant Growth Analysis: Relative Growth Rate
04 Plant Growth Analysis: Plant Communities
09 Plant Growth Analysis and Canopy Geometry
11 IN CLASS EXAM: Radiation & Growth Analysis
16 Canopy Photosynthesis: Radiation Absorption
18 Canopy Photosynthesis: Radiation Attenuation
23 Canopy Photosynthesis: Radiation Attenuation
25 Photosynthetic Efficiency Energy Conversion in Photosynthesis

01 Photosynthetic Efficiency
03 C3/C4/CAM Characteristics in Crop Plants
08 Water Use Efficiency: Stomatal Control
10 Maintenance and Growth Respiration
13 - 17 Spring Break
22 Maintenance and Growth Respiration Respiration
24 Phloem Transport: Driving gradients
29 Assimilate Partitioning: Source-Sink Relationships Energy Partitioning
31 Assimilate Partitioning: Source-Sink Relationships to Seeds

05 Phloem Transport
(TAKE HOME MIDTERM - 24 hours- due Thursday at noon)
07 Nitrogen: Uptake, Translocation, Assimilation
12 Nitrogen
14 Stress Physiology: Water
19 Absorption Capacity of Root systems
21 Stress Physiology - Temperature
26 Post-Harvest Physiology and Chilling Injury
28 Photobiology: Plant Response to Light Quality

5 COMPREHENSIVE FINAL EXAM: 9:30 am - 11:20 am

Crop Physiology (Selected readings from 7 textbooks). Purchase from Copy Center in BNR Building (about $30)

SUPPLEMENTAL TEXT (not required) Plant Physiology by Taiz and Zeiger - 2002

1. Physiology of Crop Plants
Gardner, Pearce and Mitchell - 1985
2. Basic Growth Analysis
Roderick Hunt - 1990
3. Plant Growth Analysis
Roderick Hunt - 1981
4. Plant Growth and Development
Leopold and Kridemann - 1975
5. Physicochemical and Environmental Plant Physiology
Park Nobel - 1991
6. Environmental Physiology of Plants, 2nd ed.
Fitter and Hay - 1987
7. Respiration and Crop Productivity
Jeffrey Amthor - 1989
8. Plant Physiology, 4th ed.
Salisbury and Ross - 1985
9. An Introduction to the Physiology of Crop Yield
Hay and Walker - 1990
10. Plants and Microclimate, 2nd ed.
Hamlyn Jones - 1992
11. Plant Roots: The Hidden Half. 2nd ed.
Waisel, et al. - 1996
12. Environmental Soil Physics
Hillel - 1998
13. Physiology and the Determination of Crop Yield
Boote, Am. Soc. Agronomy - 1994


I. Introduction
A. Quantitative Biology and crop modeling.

II. Growth and Development
A. Dynamic relationships between growth and yield
B. Analysis of growth in single plants
1. Relative growth rate
2. Net assimilation rate
3. Leaf Area ratio
C. Analysis of crop growth in communities
1. Crop growth rate
2. Leaf area index
3. Plant geometry - leaf angle and orientation
D. Analysis of reproductive growth
1. Harvest index
2. Source-sink relationships
3. Yield components

III. Photosynthesis
A. Theoretical maximum efficiency and actual efficiency
Quantum requirement and quantum yield
B. Factors limiting photosynthesis in the field
C. The relationship between photosynthesis and yield
D. Feedback inhibition of photosynthesis
Translocation and partitioning

IV. Respiration Efficiency
A. The different types of respiration:
mitochondrial respiration
alternative pathway respiration
B. Growth and maintenance respiration
C. Determining respiration efficiency

V. Nitrogen
A. Uptake, assimilation, and translocation of ammonium and nitrate nitrogen

VI. Stress Physiology
A. Crop water relationships
1. Evapotranspiration concepts and measurements
2. Water stress and yield
B. Temperature stress - freezing tolerance and chilling injury


Crop Physiology is both quantitative and conceptual. Exams will aspire to test conceptual understanding. There will be an in-class midterm, a take-home midterm, and an in-class final. Some of the questions on the exams will require calculations so bring a calculator to the exams. One page of notes (both sides of the page) will be allowed for reference information and equations during in-class exams.

I am strict in evaluating test answers because I think there should be little doubt about the appropriate discussion of principles. If your answer is not clear, you lose points. People also lose points by writing long answers that do not address the question.

Old tests will be on reserve in the library. The underlying basis for testing and grading is to stimulate a thorough understanding of the subject matter without intimidating or discouraging interested students. Every effort will be made to help serious students learn the material.


Computer modeling assignments 10%
In-Class Midterm 20%
Take-Home Midterm 30%
Comprehensive Final Exam 40%
TOTAL 100%

If a student has a disability that will likely require some accommodation by the instructor, the student must contact the instructor and document the disability through the Disability Resource Center. In cooperation with the Disability Resource Center, course material may be provided in alternative formats.