Exam 2
Horticulture 201 with Reed at Texas A&M University
About this deck
By: Ashley Brinegar
Textbook: The Biology of Horticulture: An Introductory Textbook
Created: 2011-10-11
Size: 53 flashcards
Views: 15
Textbook: The Biology of Horticulture: An Introductory Textbook
Created: 2011-10-11
Size: 53 flashcards
Views: 15
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Hormone
an endogenous or naturally occurring compound that is produces or synthesized in one part of the plant and causes a change in physiology, growth or development in another part of the plant; usually present in very small quantities.
Growth Substance
all naturally occurring or synthetically produced substances that affect the physiology, growth and development of plants
Auxin
hormone that causes cell elongation; discovered by Darwin; causes rooting; basipetal flow
- Indolebutyric acid (IBA) most common
- Destroyed by blue light
Cytokinin
hormone that causes cell division; acropetal flow; causes shoots
- benzyladenine (BA) most common
Gibberellic Acid (GA)
hormone that causes internode cell elongation; staminates flowers
- all plants have GA just at a perfect amount
Ethylene
hormone that kills the plant or part of; death hormone; pistillate flowers
- a gas
Abscisic Acid (ABA)
occurs in plastids, especially chloroplasts; triggers leaves to drop.
- high in fall; low in spring
- more leaves the more water loss through transpiration
Tropism
response of plants to environmental or physical stimuli.
- phototropism
- geotropism
- thigmotropism
Phototropism
response to light
Geotropism
response to gravity
Thigmotropism
response to touch
Basipetal Flow
shoot tips down
Apical Dominance
determined by apical bud, partly due to auxin produced
Herbicides - Auxin's effect
2, 4-D at high concentrations
Adventitious Root Formation - Auxin's effect
- stem and leaf cuttings
- tissue culture
Acropetal
flows down
Leaf Aging or Abscission - Cytokinin's effect
may delay
Seed Germination - Cytokinin's effect
may overcome dormancy or stimulate germination
Adventitious Root Formation - Cytokinin's Effect
- Leaf and root cuttings
- tissue culture
Rosette or Dawrf Plant - GA's effect
lack of endogenous GA often causes;
- GA acts as a growth retardant: chemicals that block GA synthesis; are usually in greenhouse and bedding plant production to produce compact plants
Flowering - GA's effect
may cause bolting in biennials
- biennials: plants the have a 2 year life cycle
Fruit Size - GA's effect
increases size of seedless grapes
Bud Dormancy - GA's effect
may overcome and substitute for cold treatment
Seed Germination _ GA's effect
may increase or speed up; subs for cold treatment
Sex Expression - GA's effect
favors staminate (male) flowers formation on monoecious plants
- monoecious: both parts on one plant
Why Dormancy?
rest and survive through winter
Fruit Ripening - Ethylene's effect
stimulates in many fruits. dying fruit.
Flowering - Ethylene's effect
triggers flowering in some bromeliads ex: pineapple
- more fruit
Flower Longevity - Ethylene's effect
causes senescence (death) of cut flowers
Leaf Abscission (Leaf Drop) - Ethylene's effect
causes in some plants
Leaf Epinasty ( curling and contortion of leaves) - Ethylene's effect
causes in some plants; first sign in leaf abscission
Sex Expression - Ethylene's effect
favors pistillate (female) flower formation on monoecious (both) plants
Dormancry - ABA's effect
causes bud or seed dormancy
Leaf abscission - ABA's effect
may cause in leaf drop in some plants
Stomata - ABA's effect
causes stomata to close (a response to drought stress)
Temperature
a qualitative measure of the amount of heat energy; you can tell temp by color
- it is a measure of the intensity or degree of heat energy
Heat
a quantitative measure of the amount of heat energy; measured in calories
- it is a measue of the quality or amount of heat energy
- faster you move, the hotter
Measures of Heat
- calorie (cal)
- Kilocalorie (kcal)
- Specific Heat
- Heat of fusion
- Heat of Vaporization
Calorie
amount of heat (heat energy) required to raise 1 gram of water by 1 degree C
- Kilocalorie - 1,000 calories
Specific Heat
amount of heat (# of calories) needed to raise 1 gram of a substance by 1 degree C ;stabilizes the temp of plants (plants are 75-95% water) ;stabilizes temp of the environment, esp. around large bodies of water
- water = 1 ;the highest specific heat of any substance
- Metal = 0.1
Heat of Fusion
amount of heat (# of calories) needed to change 1 gram of a substance from solid to liquid at its melting/freezing point; used for low intensity heat production;
- water = 80 cal/g
Heat of Vaporization
amount of heat (# of calories) needed to change 1 gram o fa substance from liquid to gas at its boiling/condensation point;
- water = 540 cal/g ;when water evaporates it cools down the atmosphere, plants, and animals
- plants keep themselves cool through their water
- Practical uses: evaporative cooling system, sprinkler irrigate greenhouse or nursery crops in mid afternoon
3 Ways to Transfer Heat (Heat Energy)
- Conduction
- Convection
- radiation
Conduction
flow of heat energy through a medium from molecule to molecule (like an oven)
Convection
mass movement of heat energy (like boiling water)
Radiation
flow of energy as electromagnetic waves, with no transferring medium; when radiation is absorbed it may be converted to heat energy
Infrared (IR) Radiation
a form of radiation easily converted to heat energy when absorbed and vice versa
Practical uses:
- infrared heaters
- radiational cooling
- frost protection with fog, smoke, and overhead coverings
Climate
the average atmospheric conditions over a long period of time
weather
the current and temporary atmospheric conditions
Global Climatic Zones
determined by position of earth relative to the sun
- Tropical climatic zone
- Temperate climate zone
- Arctic climatic zone
Tropical Climate Zone
areas between the 23.5 degree latitude N & S of equator; between the Tropic of Cancer(off the S. tip of Fla. and middle of Mexico) and the Tropic of Capricorn. Warm, rarely freezes
Temperate Climate Zone
area between the 23.5 degree and 66.5 degree latitude N & S; between Tropic of Cancer and Arctic Circle, and the Tropic of Capricorn and Antarctic Circle. Has hot and col seasons.
- subtropical: often used to describe the southern most area of the Temperate Climate Zone (ex. South Florida and Rio Grande Valley), but is not an official climates zone
Arctic Climatic Zone
area between the 66.5 degree N latitude and the N. Pole and the 66.5 degree S latitude and the S. Pole. North of Arctic Circle and south of Antarctic Circle. Always cold and frozen
About this deck
By: Ashley Brinegar
Textbook: The Biology of Horticulture: An Introductory Textbook
Created: 2011-10-11
Size: 53 flashcards
Views: 15
Textbook: The Biology of Horticulture: An Introductory Textbook
Created: 2011-10-11
Size: 53 flashcards
Views: 15
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
Think of it as a digital backpack™: access to all of your study materials online and on your phone.
STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.
“I have used this website for three exams, and I see a huge difference in my test results.”
Naj
Naj