Exam 2 Flashcards
Aerial Enviro, Irradiance, and Light
Atmosphere
Air
Thin layer no more than 12 kilo high
Hydrosphere
Water
limited supply of water in rivers, glaciers lakes and underground
Lithosphere
Soil
Crust of soil minerals and rocks going 1 thousand meters into earths crust
Aerial environment
portion of ecosphere that exists above soil and to the tip of the plant
-Irridiance, temp, atmosphere, organisms
Components of aerial environment
irradiance and temp result of thermonuclear radiation from sun
atmosphere pollution harmful to plants
pollinators or pathogens
ultimate source of irradiance and ultimate black body ?
solar radiation/the sun
Thermonuclear fusion
reactions inside the sun-
Hydrogen converting to Helium
Nuclear fission
induced fission reaction
(Uranium 235)
bunsen burner color
depends on oxygen supply
electromagnetic spectrum
light is both wave and particle
how a rainbow forms
bending of light through atmospheric rain droplets results in light moving into respective bands = rainbow
photoelectric effect
zinc exposed to UV light releases electrons and becomes + charge.
These e create electrical current that can be measured
(the turn circle video from class)
quantum theory
quantum energy of wavelength is proportional to its freq and WV
color blindness
red, blue , green cone disorder
If there were no scattering of air molecules, the sky would be
pitch black and stars visible all day long
solar zenith angle
dominant direction of sun rays
where will shade be thrown?
surface intensity
amount of light in location with climate
-seasonal differences, latitude and clouds
AZ and NV highest in summer and winter
photochemical reactions
ability of irradiance to affect bio organisms
light-> photoreceptor-> primary reaction-> 2nd action-> development
radiometry
measurement of flux
spectroradiometry
measures radiant flux dependent upon the WV of the radiation
pyranometer
measure solar radiation
photometry
measures CIE photopic curve
(human eye measurement)
PAR
measures flux used by plants
UV damage
DNA- absorbs UV-B radiation and breaks the dna coding path
skin- skin cancer
mutations- added limbs
snow blindness
how plants use light?
photomorphogenesis
light can impact seed growth
weeds use light to germinate earlier
chlorophyll synthesis
germination in the dark= etiolated spindly yellow growth
green shows when light is present
chloroplasts in light
low light- orient flat to maximize surface area
high light- stack to protect against death
how do plants protect against sun?
curl leaves to avoid water loss
waxy coating
change angle of leaves to avoid sun rays
LAI
quantity of leaves on crop
structure of canopy by # of land surface area
4-6
Phytochrome
pigment responsible for photomorphogenic growth responses
red and far red ratios
red light = good plant
far red light= etiolated plant
exposure to light follows last light to grow
Decoteau’s black box
how we learned plants respond to different colors of light?
-break light off into diff. colors to treat plants
-measure growth of each light
photoperiodism to change flowering
flash light = long day= energy daver = doramcy and flowering impact
cryptochrome
blue light pigment
Practical uses of growth regulators
reduces height by inhibiting gibberellins in stem petals and flowers
row orientation and light
east-> west= utilize light more efficiently
north to south shade eachother easier
greenhouse orientation and light
north-> south= morning sunshine
filtering light
emitted radiation can be modified with the uses of filters, shade cloth…
types of filters
neutral density- reduce light intensity without changing light quality
color filter- used to remove certain colors
energy friendly filters
vegetation, trees, manipulating light for home heating/cooling
spectral filtering
modify incoming sunlight
-light comes thru corrugated panels filled with colored water
-hot water heats greenhouse
feeding space
uses nutrient film hydroponics with reflective walls to retain light
explain the outcome of three treatment groups for phytochrome light treatments
red- shorter and more compact
far red- taller stems to reach for more light
far red interrupted- similar to red, reverts far red light impact
explain the varied ways to orient your rows for economic optimization
follow slope of land= more access to light, but hard to harvest
straight lines= quicker to work, less light availability
in regards to sunlight, which orientation of rows is more efficient?
East to west because it follows the natural sun movement in the sky throughout the day
explain how and why chlorophylls move when exposed to high or low light
chlorophyll cells move to be more spread out when in low light to cover more leaf surface area= more sunlight
in high light, they stack to avoid stress
why are PAR sensors generally more useful than other radiation measuring instruments?
they measure the wavelength of absorption of sunlight that is most efficient for photosynthesis
why is it beneficial for plants to be able to measure the ratio of red to far red light ?
to help avoid growing over eachother. no unwanted stretch
proximity to other plants
what are the layers of the ecosphere
atmosphere- air
hydrosphere- water
lithosphere- soil
what is the difference between solar noon and 12:00 noon?
solar noon is around 2-4pm in PA
describe photomorphogenesis, what pigment is important and provide an example of a photomorphogenic response in plants
light mediated development of plants where plants respond to light environment
phytochrome is an important pigment that regulates the germination of seeds in response to the absence or presence of light
Heliotropism is when sunflowers follow the sun through the sky to be more visible to pollinators
