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Crop Science Test 3
Test 3
513
Agriculture
Undergraduate 2
10/28/2016

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Cards

Term
2 different types of population/yield interactions
Definition
-those based on seed yield
-those based on population yield
Term
2, 4-D
Definition
type of synthetic auxin; behaves as broadleaf weed killer
Term
3 approaches to monitoring soil moisture for irrigation needs
Definition
1: "water balance" approach
2: soil moisture blocks
3: time domain reflectometry
Term
3 classes of plants based upon flowering response
Definition
a. Long day plants
b. Short day plants
c. Day neutral plants
Term
3 classes of plants based upon flowering response
Definition
1: long day
2: short day
3: day neutral
Term
ABA
Definition
abscisic acid
Term
Auxin also produced at...
Definition
meristematic regions near the root tips
Term
Auxin is involved in apical dominance, which means...
Definition
when you have high auxin, you have no branches
Term
Basal cell develops into...
Definition
suspensor
Term
Both types of p’synth are driven by...
Definition
light
Term
Bulliform cells
Definition
the big cells on the epidermis
Term
C3 plants vs. C4 plants regarding CO2 compensation point
Definition
C3 plants have a higher CO2 compensation point than C4 plants
Term
C3 vs. C4 plants under conditions of hot, dry, and bright sunlight
Definition

-C4 plants are p'synthetically more efficient under these conditions

-under such conditions, C4 plants don't photorespire like C3 plants

Term
C4 p'synth requires an extra set of...
Definition
light rxns
Term
CO2 compensation point
Definition
the c'tration of CO2 at which plants show no net fixation of CO2, that is, the point at which CO2 uptake and evolution are at equilibrium
Term
CO2 compensation point of C3 plants
Definition
50 ppm (soybeans)
Term
CO2 compensation point of C4 plants
Definition
10 ppm (corn)
Term
Crop growth is a balance between ______ and ______
Definition
psynth (gain)
respiration (loss)
Term
Daily heat unit aka...
Definition
growing degree days (GDD)
Term
Factors affecting net PS
Definition

-Temperature (increases respiration and photorespir.)

-Light (low light decreases photosynthesis)

-CO2 concentration (compensation point)

-Water availability, (low turgor and stomata close), (stomata close before wilting begins), (leaf cooling effects)

Term
Factors affecting water use efficiency (WUE)
Definition
-Species (C3 vs. C4)
-Pop. Density
-Soil moisture
-Health of plant (diseases/insects)
-Relative Humidity
-Wind
-Weeds
Term
Factors affecting water use efficiency (WUE) that we have control over
Definition
-Species (C3 vs. C4)
-Pop. Density
-Soil moisture
-Health of plant (diseases/insects)
-Weeds
Term
Following germination and utilization of seed food reserves, plats are on their own to...
Definition
acquire, store, and utilize energy for growth and maintenance
Term
GA can be used to break this in some seeds
Definition
dormancy
Term
How Does a Seed Develop?
Definition
-Double Fertilization
-Development of the Embryo and Endosperm
-Cell expansion and maturation
Term
If you don’t have adequate moisture, this happens to the germinating plant
Definition
it dies
Term
Increase in CO2 c’tration is good for...
Definition
C3 plants
Term
Latent heat of vaporization
Definition
amount of heat needed to change 1 mL (cc) of water to vapor
Term
Latent heat of vaporization for water
Definition
539 calories
Term
Leaf Area Duration (LAD)
Definition
duration for which a specific leaf area remains p'synthetically active after expansion
Term
Leaf Area Index (LAI)
Definition
Unit of leaf area per unit of soil area (leaf area index)
Term
Leaf Area Index (LAI) is a measurement of...
Definition
surfaces available for light interception by crop community rather than individual plants
Term
Low relative humidity means high...
Definition
evapotranspiration
Term
Net Photosynthesis
Definition
Net Photosynthesis = Photosynthesis – Respiration

(This is GROWTH)
Term
PGA
Definition
phosphoglyceric acid
Term
PGAL
Definition
phosphoglyceraldehyde
Term
Pigweed aka...
Definition
Palmer amaranth
Term
Rize-up
Definition
Giberellic Acid that’s spread onto pastures that got ryegrass such that the grass is primed to continue growing
Term
The heat from the sun is the...
Definition
photons
Term
The limitations on p’synth are associated with...
Definition
light and diffusion rate between outside and inside of leaf
Term
The problem with pan evaporation and rainfall
Definition
they don’t match up very well
Term
The relationship between Pred and Pfred causes...
Definition
flowering
Term
Vernalization
Definition
type of floral induction; this is a response to cold conditions; some crops have to be vernalized before they can go from vegetative growth to reproductive growth
Term
Visible spectrum
Definition
390-760 nm
Term
Water is essential to cool plant. Failure to do so results in...
Definition
-decreased photosynthesis
-decreased leaf area
-reduced competitiveness
-susceptibility to pests.
Term
Water needs/use drop after...
Definition
flowering
Term
Wavelength referred to as...
Definition
lambda
Term
We have to have heat units that initiate...
Definition
vernalization
Term
When does CO2 become limiting in supply?
Definition

-Drought (stomatal opening)

-Heat – CO2 fixation process occurs faster than CO2 entrance

Term
a day length sensor in the plants
Definition
the blue light sensory system of cryptochromes
Term
a disadvantage of RUDP carboxylase
Definition
it's O2 sensitive and therefore inefficient unless CO2 is high (photorespiration)
Term
a disadvantage of gated pipe irrigation
Definition
Lots of runoff in this system
Term
a type of special separation that occurs in C4 p'synth
Definition
special separation of C4 (mesophyll) and C3 (bundle sheath) p'synthetic systems of C4 plants
Term
abscisic acid aka...
Definition
dormin
Term
absence of this in C4 plants makes C4 plants more efficient w/ water (higher WUE)
Definition
photorespiration
Term
advantage of PEP carboxylase
Definition
it is not O2 sensitive and therefore efficient at all O2/CO2 c'trations
Term
advantages of the water balance approach
Definition
-No special equipment needed
-Easy to implement
-Inexpensive
Term
advantages of time domain reflectometry to determine irrigation needs
Definition
-Can automate with irrigation system
-Easy to implement
-Moderate (not prohibitive) expense
Term
amount of biomass vs. water need
Definition
a crop that produces more biomass requires more water, regardless of efficiency
Term
amount of energy reaching the Earth's surface
Definition
about 100,000 langleys, which is about which is about 1 billion calories per M-2
Term
amount of leaf area could be impacted by...
Definition
management of the crop
Term
amount of water used by ag
Definition
Ag uses about 85% of all the water supplies globally
Term
an advantage C4 plants have in terms of carbon utilization
Definition
C4 plants are extremely efficient in their carbon utilization
Term
an advantage of gated pipe irrigation
Definition
low cost
Term
an obstacle of irrigation
Definition
costly; therefore, it must be efficient and we can't afford to overapply
Term
another difference between seed yield and biological yield
Definition
seed yield is parabolic and biological yield is asymptotic
Term
at this w'length, proportion of energy converted is high because little energy is left over after electron excitation
Definition
760nm
Term
at this w'length, there is almost no absorption of light and therefore energy not used to excite electron
Definition
525nm
Term
auxin is involved in this dominance
Definition
apical dominance
Term
base temp for corn
Definition
15°C
55°F
Term
base temp for wheat
Definition
5°C
41°F
Term
biomass vs. water use
Definition
High Biomass = High Water Use
Term
bundle sheath cells in warm season grasses have this mechanism for p'synth
Definition
C3
Term
cardinal temperatures
Definition
temps at which crops (plants) cease to actively grow
Term
catastrophic events that can happen in epigeal germination
Definition
-defoliation
-frost
-hail damage
-seed rot
Term
catastrophic events that can happen in hypogeal germination
Definition
none except for seed rot
Term
chart showing soil texture vs. available water
Definition
[image]
Term
chemotaxic response
Definition
directional response to chemical element
Term
cool season grasses and all C3 plants have this in their mesophyll
Definition
C3 stuff
Term
critical LAI
Definition
-the LAI where there’s greatest seed production and greatest grain yield
-the LAI where we get 95% light interception
-rate of dry matter production is asymptotic (i.e. somewhat constant over various LAI)
-leaves are upright or do not become parasitic
Term
crop for which the critical LAI concept doesn't work
Definition
cotton
Term
crop responses to drought depends on...
Definition
stage of development of the crop
Term
crop yield (grain) is largely dependent upon these things pertaining to radiation utilization by a crop surface
Definition

-Intensity and duration of sunlight

-Light interception

-Efficiency of interception (upper vs. lower leaves)

-Efficiency of conversion (C3 vs. C4)

-Distribution of carbohydrates in plants (i.e., roots, stems, and seeds)

Term
cross section of cool season grass
Definition
[image]
Term
cross section of the leaf of a C3 plant
Definition
[image]
Term
cross section of warm season grass
Definition
[image]
Term
cryptochromes
Definition
series of compounds thru which plants respond to blue light
Term
cytokinins interact w/ auxins to do this
Definition
differentiate cell types
Term
cytokinins stimulate...
Definition
cell division
Term
day neutral plants
Definition
plants that develop flowers regardless of day length
Term
depiction of Double fertilization of plant ovules
Definition
[image]
Term
depiction of Photosynthesis in Warm Season Grasses
Definition
[image]
Term
depiction of ovule and ovary in a flower
Definition
[image]
Term
depiction of some processes that happen in the stroma in p'synthesis
Definition
[image]
Term
depiction of some processes that happen in the thylakoids in p'synthesis
Definition
[image]
Term
depiction of the Calvin cycle
Definition
[image]
Term
depiction of the electron transport in p'synth
Definition
[image]
Term
depiction of the interaction of Pred phytochrome and Pfred phytochrome
Definition
[image]
Term
depiction of the light rxns that occur in photosynthesis
Definition
[image]
Term
depiction of the sequence of seed development from fertilization onwards
Definition
[image]
Term
depiction of what happens in the chloroplasts during p'synthesis
Definition
[image]
light rxns on left, dark rxns aka Calvin cycle on right
Term
depiction of what happens in the stroma in the bundle sheath cells in C4 p'synthesis
Definition
[image]
Term
depiction of what happens in the stroma in the mesophyll cells in C4 p'synthesis
Definition
[image]
Term
depiction of what happens in the thylakoid membranes in both the mesophyll cells and the bundle sheath cells in C4 p'synth
Definition
[image]
Term
disadvantages of the water balance approach
Definition
-Assumes soil retains 100% of rainfall
-Does not account for atmospheric conditions
+Wind
+Humidity
Term
disadvantages of time domain reflectometry to determine irrigation needs
Definition
-Electronic failures are bad news
-Tillage can damage probe; therefore, take it out before tilling
-Assume that probe is placed in an area of field which is representative of the entire field; if you have multiple soil types in a field, you have to put multiple in the same field
-Must calibrate for each soil type
Term
does efficient water use guarantee a crop?
Definition
NO!
Term
evaporation
Definition
water loss from soil and puddle surfaces in field; not plant process
Term
example of how growth models can be used as a management aid
Definition
something regarding hail, frost, disease, and insect damage to a crop
Term
example of photoperiod response differing due to cultivar
Definition
different groups of soybeans require shorter nights
Term
example of plant having cold requirement
Definition
winter wheat
-plant in fall --> vernalize in winter --> flower in spring
-plant in spring --> no flower
Term
factors affecting p'synth and photorespiration
Definition

-temp

-CO2

-light

-wilting

Term
factors in Evaluating Light Interception and Use
Definition
-Total area of leaves
-Efficiency of the canopy
-Modifications of leaf area and efficiency (disease, insect, weed competition)
-Duration leaf remains on the plant (leaf area duration)
-Day and season length
Term
factors of Radiation Utilization
Definition

-Intensity and duration of sunlight

-Light interception

-Efficiency of interception (upper vs. lower leaves)

-Efficiency of conversion (C3 vs. C4)

-Distribution of carbohydrates in plants

Term
female part of the corn flower
Definition
ear
Term
first lag phase
Definition
this is the phase where the plant is in transition from seed storage to p'synthetic energy supply
Term
floral induction
Definition
conditioning of plant to enable plant to enable shift of vegetative to reproductive growth
Term
floral induction
Definition
conditioning of plant to enable shift of vegetative to reproductive growth
Term
floral induction by heat units
Definition
accumulation of heat above and beyond some base temp required for a plant to grow
Term
floral initiation
Definition
flowers being exposed to light and such
Term
floral initiation
Definition
changing of growth from vegetative to reproductive
Term
function of respiration
Definition
mobilizes stored compounds and utilizes energy
Term
gated pipe irrigation not too common here in the Southeast, except for...
Definition
the Delta region in Mississippi
Term
gated pipe irrigation used on...
Definition
heavier textured soils
Term
general anatomy of a thylakoid
Definition
[image]
Term
general process of the dark rxns in C3 p'synthesis
Definition
[image]
Term
get this into the field before harvest
Definition
equipment
Term
growing degree days (GDD) aka...
Definition
heat units
Term
the 2 pigments involved in photoperiodism
Definition
-phytochrome -cryptochrome
Term
hard dough
Definition
seed becoming brittle; can't depress w/ thumb nail (~40% moisture)
Term
heat is a driving force of this in plants
Definition
growth and development
Term
heat units aka...
Definition
growing degree days (GDD)
Term
here in Georgia, drip irrigation is used mostly in...
Definition
horticultural areas
Term
hormone
Definition
compound which, when present when present at extremely low c'trations, in the plant, exert measurable physiological and morphological changes which affect plant growth
Term
hormones in plants can also be called...
Definition
growth regulators
Term
how available soil water is expressed
Definition
inches of water per foot of soil
Term
how cryptochromes influence flowering
Definition
they interact with phytochrome to control flowering, but no one knows the mechanism of the interaction other than the scenario in the book
Term
how cryptochromes influence flowering
Definition
by interacting w/ phytochrome to control flowering
Term
how double phy a and phy b affect flowering
Definition
plants with double phy a and phy b will flower earlier than plants with the recessive phy b and dominant phy A
Term
how drought can restrict root growth
Definition
limiting water to plant for function
Term
how efficiency is measured in grain crops
Definition
Pounds of grain/pounds of water
Term
how excess moisture can lead to reduced grain quality
Definition
diseases infecting seed heads/pods
Term
how excess moisture can reduce soil quality
Definition
leaching minerals from soil, making them unavailable to plants
Term
how leaves become functionless in senescence
Definition
they translocate metabolites (proteins, CHO) to seeds and become functionless
Term
how long it takes for an embryo to turn into a corn seed
Definition
25-30 days
Term
how long it takes for an embryo to turn into a cotton seed
Definition
maybe 60 days
Term
how many different types of gibberellins are there?
Definition
80
Term
how many times the Calvin cycle goes around and why
Definition
Calvin cycle goes around 3 times because you’re fixing 3 C and you get phosphoglyceric acid
Term
how p'system 1 replenishes its electrons
Definition
by splitting water, releasing electrons into p'system 1 and H+ ions and O2 in the thylakoid compartment
Term
how pollen grain interacts with ovules
Definition
Pollen grain on stigma, which is low energy, pursues ovules, which are high energy
Term
how population density affects WUE
Definition
higher population density means lower water use efficiency

this is because of lower HI, whatever that is
Term
how relative humidity affects WUE
Definition
higher relative humidity leads to higher WUE due to less evaporation
Term
how temp affects flowering
Definition
cool temps delay flowering
Term
how the amount of available soil moisture affects WUE
Definition
easier to extract water when a lot is present (field capacity); this means lower WUE
Term
how the health of the plant affects WUE
Definition
pathogens and insects reduce the capacity to produce yield, but don't change water use; this leads to lower WUE
Term
how the nomenclature of photoperiodism changed
Definition
the nomenclature of Pred and Pfred was replaced in 2003 with phytochrome A-E
Term
how the phytochrome/cryptochrome interaction occurs
Definition
not known, but evidence is showing that cryptochromes regulate GA production in the flower
Term
how the rate of transmission of water has to be distributed in a center pivot irrigation system in order to be uniform
Definition
Rate of transmission of water has to be greater on the outside than on the inside
Term
how the type of Phytochrome B allele affects flowering
Definition
those that have recessive (phy b) flower earlier than those w/ dominant (phy B)
Term
how the type of phytochrome A allele affects flowering
Definition
plants w/ a recessive phytochrome A gene (phy a) lose the ability to respond to flashes of light in the middle of the night
Term
how to calculate Leaf area index (LAI)
Definition
(LAI)=(area of leaves)/(area of ground)
Term
how to calculate WUE
Definition
WUE=(T yield/T water)
Term
how to calculate crop water needs using the water balance aoproach
Definition
(crop needs)-rainfall
Term
how to calculate daily heat unit
Definition
Daily heat unit = ((daily max temp + daily min temp)/2) ‑ minimum cardinal temp
Term
how to calculate heat unit aka growing degree day
Definition
((daily max temp + daily min temp)/2) - minimum cardinal temp
Term
how to calculate irrigation need using the water balance approach
Definition
water use-rainfall=irrigation need
Term
how to calculate total heat units
Definition
Total heat units = Σ(daily heat units)
Term
how to do the "water balance" approach of monitoring soil moisture for irrigation needs
Definition
Basically, you every day calculate rainfall from the past 7 days and based upon the rainfall you have, you can estimate how much water is available to the plant for use and you estimate water use based upon stage of development of the crop
Term
how we can increase our water use efficiency
Definition
by using our ag management practices something like that
Term
how weeds affect WUE
Definition
compete for water, fertilizer, light
Term
how wind affects WUE
Definition
increases transpiration w/o increased p'synth
Term
how you might wanna plant the rows to get the best energy utilization
Definition
Might wanna plant the rows closer together to get the best energy utilization
Term
immature seeds can be treated w/ ethylene (ethephon) to promote...
Definition
after ripening
Term
immature seeds can be treated w/ this to promote after ripening
Definition
ethylene (ethephon)
Term
importance of length of day to flowering
Definition
extremely important
Term
importance of stand density for seed yield
Definition
important to get a stand dense enough for optimum yield, but too much results in reduced yield
Term
in photorespiration, there's competition of ______ for ______
Definition

O2

RUDP CO2ase

Term
in the log phase, this buffers plants to leaf defoliation
Definition
rapid leaf expansion
Term
induction
Definition
temp response (i.e., vernalization ad accumulation of heat)
Term
initiation
Definition
light response
Term
is the rate of diffusion affected by temp?
Definition
no
Term
is the senescence process reversible?
Definition
no
Term
less auxin and less cytokinin leads to...
Definition
roots
Term
less auxin and more cytokinin leads to...
Definition
buds
Term
light above this w'length doesn't carry enough energy to excite an electron
Definition
760nm
Term
limitations of heat unit models
Definition
1) other variables influence crop growth
2) Planting date can change ability to predict stage of development.
Term
limiting factors in the harvest of corn, soybeans, and peanuts
Definition
quality
Term
limiting factors in the harvest of cotton
Definition
perennial plant
Term
limiting factors in the harvest of wheat in fall
Definition
Hessian fly
Term
limiting factors in the harvest of wheat in spring
Definition
frost
Term
linear phase
Definition
leaf area continues to expand, but plant has been induced to develop reproductive parts

plant buffered to leaf defoliation because of rapid leaf expansion
Term
log phase
Definition
the phase where leaf area expansion is extremely rapid
Term
long day plants
Definition
respond to days getting progressively longer
Term
male part of the corn flower
Definition
tassel
Term
manage soil water to keep it at this level of available water
Definition
between 40% and 90% available water
Term
milk stage
Definition
endosperm liquid when pressed between thumb nail; looks like milk
Term
more auxin and less cytokinin leads to...
Definition
undifferentiated growth
Term
mother plant transfers ______ to seeds and loses ______
Definition
energy
leaves
Term
new fact about photoperiodism
Definition
2 pigments involved: phytochrome and cryptochrome
Term
old theory of photoperiodism
Definition
phytochrome interaction w/ daylight (Pred and Pfred)
Term
one crop in which reduced seeds per plant is proven
Definition
corn
Term
one crop where nearly all the seeds are treated with ethylene (ethephon)
Definition
peanut
Term
one form of seed dormancy
Definition
immature embryo
Term
one possible reason for reduced yield at higher density
Definition
as population density increases, the number of plants that are barren (seedless) increases, thus yield reduction
Term
optimum LAI
Definition
crop surface has a definite LAI at which an increase results in decreased productivity
Term
optimum conditions for leaf area index (LAI)
Definition
-All leaves photosynthesizing
-Maximum light interception
-Grain vs. forage vs. turf
Term
overall p'synth rxns in plants
Definition
[image]
Term
overall rxn of p'synth
Definition
6CO2 + 12H2O + light --> C6H12O6 + 6H2O + 6O2
Term
overly simplified model of photoperiodism
Definition
[image]
Term
p'synth and respiration can't function without...
Definition
adequate supply of...
-water
-mineral nutrition
-heat
-light
Term
p'system affected by...
Definition
light only
Term
pan evaporation
Definition
basically the amount of evaporation off of a soil surface
Term
photoperiod response differs due to...
Definition
cultivar
Term
photorespiration causes ribulose (a sugar) to do this
Definition
respire
Term
photorespiration causes this to respire
Definition
ribulose (a sugar)
Term
photosynthesis
Definition
the process of converting light, H2O, and CO2 into chemical energy
Term
physiological maturity in seeds
Definition
embryo and endosperm are fully developed and can survive independent of parent plant
Term
phytochrome A and B are produced as a result of...
Definition
transcription of a gene for each
Term
plants respond to blue light through...
Definition
a series of compounds called cryptochromes
Term
pollination
Definition
transfer of pollen from anther to stigma and fertilization of female gametes
Term
pollination consists of theses 2 separate physiological processes
Definition
1: seed set
2: fertilization of the egg
Term
population/yield interaction based on biological yield
Definition
yield of total plant weight per unit area (tons/A, MT/HA)
Term
population/yield interaction based on seed yield
Definition
weight per unit area of the grain portion of the plant (bu/A, kg/ha)
Term
primary pigment in chloroplast
Definition
chlorophyll
Term
purpose of the heat unit concept
Definition
concept developed to try and predict physiological events in plant
Term
reduction and fixation of CO2 are controlled by...
Definition
temperature (linear increase with temp)
Term
regulation of most plant functions is a result of...
Definition
interactions among hormones
Term
regulation of most plant functions is not a result of...
Definition
presence or absence of a hormone
Term
respiration is the opposite of...
Definition
p'synth
Term
seed set
Definition
prevention of flower abortion or drop
Term
short day plants
Definition
late summer/fall flowering; plants that respond to short days, long nights

days must get shorter to trigger tissue differentiation
Term
soft dough
Definition
endosperm soft when pressed w/ thumb nail
Term
solid set irrigation used for...
Definition
lawns and such
Term
some C3 crops
Definition
-Cotton*
-Peanuts*
-Soybeans *
-Tobacco *
-Wheat
-Oats
-Barley
-Rye
-Canola (Rape)
-Orchardgrass
-Tall Fescue
-Clovers
-Alfalfa
Term
some C4 crops
Definition
-Corn
-Grain/forage sorghum
-Pearl millet (forage)
-Bermudagrass
-Zoysia
-Centipede
-Seashore Paspalum
Term
some C4 weeds
Definition
-Pigweed (Palmer Amaranth)*
-Common Bermudagrass
-Johnson grass
-Wiregrass
-Cogon grass
Term
some Field Equipment for Soil Water Management Under a Center Pivot Irrigation System
Definition
-White box containing data logging and transmitter
-Solar power charges battery and transmits soil water information to a computer in manager’s office
Term
some Limitations to C3 Photosynthetic systems
Definition

-Ribulose bis phosphate carboxylase (oxygenase) is O2 sensitive

-CO2 entrance into leaf is a diffusion process – limited access

-If CO2 is in limited supply, then the process turns to respiration (no net gain in weight)

Term
some considerations for application rate in irrigation
Definition
-Soil type (sandy soils hold less water than clay soil)
-Crop demand
-Time needed to replenish soil moisture
-Probability of severe drought
-System design
+Low vs. high pressure (radius of throw)
Term
some considerations for irrigation
Definition
-Rate of distribution
-Efficient distribution
-Stage of development of crop
-Expense of doing this
Term
some crop responses to excess moisture
Definition
-root growth restricted
-delayed maturity(late in season)
-reduced grain quality
Term
some crops that are too reliant on RoundUp
Definition
-cotton
-soybean
Term
some crops that have the vernalization type of floral induction
Definition
-wheat
-oats
-cereal rye
Term
some details about auxin
Definition
-Produced by dividing cells (apical meristem)
-Important for cell elongation
-Control apical dominance
-Synthetic auxins (2,4-D) used as herbicides
Term
some details about cytokinin
Definition
-stimulate cell division (Bud, embryo development)
-Produced primarily in roots (xylem transport; transported only in the xylem, so it’s a one direction flow)
-Interacts with auxins
Term
some details about gibberellins
Definition
-over 126 types in plants!
-Each has its own function
-Produced in young leaves, roots (phloem transp.)
-Generally,
+promotes stem elongation
+promotes seed germination
+promotes fruit set (after pollination)
Term
some details about light
Definition
-light moves in discrete packages called photons
-photons strike chlorophyll and excite an electron
-energy from excited electron is transferred to other compounds
-different photons travel at different speeds with different w'lengths
-each w'length represents a different color and the longer the w'length, the less energy it contains- this is called radiant energy
Term
some hormones that control the development of crops
Definition
-Auxin
-Giberellic acid
-Cytokinins
-Abscisic Acid
-Ethylene
Term
some interactions between cytokinin and auxins
Definition
-High auxin, low cytokin – undifferentiated cell growth
-Low auxin, high cytokin – bud devel. and growth
-Low auxin, low cytokin – root growth (in culture)
Term
some irrigation methods for field crops
Definition
-aerial irrigation (sprinkler)
-surface irrigation (furrow and flood irrigation)
Term
some limitations of heat unit models
Definition
-other variables influence crop growth
-planting date can change ability to predict stage of development
Term
some management decisions that can affect the radiation utilization by a crop
Definition
-irrigation
-mowing height
-population
-density
Term
some modifications of leaf area and efficiency
Definition
-disease
-insect
-weed competition
Term
some plants that are long day plants
Definition
-spring flowering plants
-barley
-oats
Term
some possible crop responses to drought
Definition
-poor germination
-restricted root growth
-leaf rolling, drooping, senescence
-few tillers or branches
-fewer fertile flowers
-shriveled seed
Term
some process and signaling that cryptochromes are involved in
Definition
-involved in phototropism
-involved in plant/plant signaling
Term
some reasons C4 plants are more efficient at p'synth
Definition

-special separation of C4 (mesophyll) and C3 (bundle sheath) p'synthetic systems of C4 plants

-RUDP carboxylase is O2 sensitive and therefore inefficient unless CO2 is high (photorespiration)

-PEP carboxylase is not O2 sensitive and therefore efficient at all O2/CO2 c'trations

Term
some things in plants that are controlled by hormones
Definition
-germination
-growing
-flowering
-seed production
Term
some things that affect respiration
Definition

-temperature

-O2 concentration

-Availability of CHO in the plant

-tissue age (young respires more)

Term
some things that can be done to use water, nutrients, and solar radiation more efficiently
Definition
-increase plant population
-shift plant distribution
Term
some things that cryptochromes are involved in
Definition
-phototropism
-plant/plant signaling (population density or "neighbor" effects)
Term
some things that happen in cyclic phosphorylation (photophosphorylation)
Definition

-electron is passed to series of proteins which convert energy to ATP

-each protein the electron is passed to results in released energy that results in ADP and Pi to form ATP (short term energy storage and transfer)

-electrons are passed to a series of enzyme which bind H to NADP to form NADPH

Term
some things that happen in non-cyclic photophosphorylation
Definition

-light splits H2O as well as excite electron

-H+ goes to p'system 1 for conversion to NADPH

Term
some things that happen in the dark rxns
Definition

-ATP + NADPH active in dark rxns

-in these rxns, H2 is given up by NADPH to fix CO2 into carbohydrate

-ATP is used to transfer p'synthetic precursors used in in dark rxns

-2 p'synthetic pathways are involved: C3 and C4

Term
some things that must be managed or controlled in log phase
Definition
-insects and diseases which limit leaf growth
-weeds still need control
-floral induction parameters must be met
Term
some types of day neutral plants
Definition
-corn
-cotton
-tobacco
Term
some types of short day plants
Definition
-rice
-soybeans
Term
some variables that can influence crop growth other than heat
Definition
-light
-moisture
Term
some ways to calculate crop water need
Definition
-water balance approach
-pan evaporation
Term
something about gibberellins in semi-dwarf wheat
Definition
can't produce as much and has less energy put into stems and more into seeds
Term
something flower drop can cause in crops
Definition
loss of yield potential
Term
something flower drop can do in soybeans
Definition
cause them to lose yield potential
Term
something in plants that senses blue light
Definition
cryptochromes
Term
something overirrigation an lead to
Definition
surface runoff or excessive subsurface lateral flow, thus removing water from field
Term
something that can happen with corn at high density other than reduced yield
Definition
tassel only (no ear)
Term
something that can influence the amount of daylength
Definition
latitude
Term
something that can prevent harvest in fall
Definition
rain
Term
something that happens late in the linear phase
Definition
plant is flowering-- grain fill begins

leaf area duration critical
Term
something that needs to be controlled during the linear phase
Definition
disease/insect activity that feeds on flower/bud
Term
something that needs to be done in the first lag phase of crop development
Definition
weeds need to be controlled to permit normal plant development
Term
specific heat
Definition
amount of heat needed to raise the temperature of water 1°C (= 1 calorie); 1 calorie is the amount of energy it takes to raise the temp of 1 gram of water 1°C
Term
specific heat of water
Definition
1 calorie
Term
speed at which the phytochrome goes from Pfred to Pred
Definition
slow
Term
speed at which the phytochrome goes from Pred to Pfred
Definition
instantly
Term
spray this to set fruit in grapes and make them seedless
Definition
GA
Term
stages of crop development
Definition
1. Germination
2. Root growth
3. Leaf development and expansion
4. Stem elongation and continued leaf and root development
5. Flowering
6. Fertilization and seed development
7. Seed maturation and dehydration
Term
strengths of using soil moisture blocks for determining irrigation needs
Definition
-Accurate estimate of soil water content
-Simple once calibrated
-Easily automated
Term
temperature vs. rate of rxn
Definition
As the temp goes up, the rate of rxn goes up
Term
terminal cell develops into...
Definition
embryo proper
Term
the 2 forms of cryptochromes that have been found
Definition
-cryptochrome A
-cryptochrome B
Term
the 2 forms of phytochrome
Definition
-Pred (P red)
-Pfred (P far red)
Term
the 2 important physiological processes of pollination
Definition
1: seed set
2: fertilization of the egg
Term
the 2 ways floral induction can happen
Definition
-Vernalization
-heat units
Term
the 3 steps of p'synth
Definition

-p'system conversion to ATP and NADPH2 used to reduce CO2

-diffusion of CO2 from outside of plant to inside

-reduction of CO2 and fixation into CHO

Term
the 5 known forms of cryptochrome
Definition
cryptochrome A
cryptochrome B
cryptochrome C
cryptochrome D
cryptochrome E
Term
the 5 major groups of plant growth regulators
Definition
-auxins
-gibberellins
-cytokinins
-abscisic acid
-ethylene
Term
the C3 crops that have deep roots, making it important to break up those hard pans
Definition
-Cotton*
-Peanuts*
-Soybeans *
-Tobacco *
Term
the Q10 of 2 means...
Definition
for every 10°C increase in temp, the biochem rxns double in rate
Term
the ability to use hormones to transform plants via biotech and repeating the life cycle of plants in vitro is vital for...
Definition
genetic engineering
Term
the advantages of having C4 photosynthesis
Definition
1: Have a mechanism that is not responsive to oxygen deprivation in mesophyll cells.
2: Place the oxygen sensitive system in cells which are CO2 enriched.
3: System is not limited during heat
4: System is not as limited during drought (drought tolerant)
Term
the amount of energy in sunlight compared to what's needed
Definition
sunlight has 50-100 times as much energy as is needed
Term
the amount of sunlight on the surface of the soil
Definition
123,000 Langleys reaching surface of the soil = 10 kw hr/m2/sec
Term
the amount of water that gets used for plant function
Definition
about 1% of what's taken up
Term
the cyclic utilization of electrons
Definition
cyclic phosphorylation (photophosphorylation) (PSI)
Term
the different stages seeds go thru during ripening
Definition
-milk stage
-soft dough
-hard dough
-physiological maturity
Term
the different types of irrigation
Definition
-center pivot (high pressure)
-center pivot (low pressure)
-traveling gun
-solid set
-gated pipe
-drip irrigation
Term
the disadvantages of having C4 photosynthesis
Definition
1: Needs twice as much light as C3 plants 2: Require more heat for growth
Term
the effect of frost during linear phase
Definition
kills developing embryo
Term
the effect of leaf angle
Definition
affects how much energy is intercepted and used
Term
the effects of longer Leaf Area Duration (LAD)
Definition
-Longer LAD after pollination will give us greater seed fill
-Longer LAD will give us more grazing resistant forages
-Longer LAD will give us more tolerant of clipping (turf)
Term
the energy gradient in the pistils
Definition
stigma is low energy and ovules are high energy
Term
the first event in seed germination
Definition
movement of GA from cotyledons to embryo to initiate the germination process
Term
the function of p'synth
Definition
builds and stores energy compounds
Term
the grain fill process
Definition
1: after fertilization, plant transports nutrients to developing seed
2: seed accumulates nutrients (endosperm or cotyledons) and goes thru different stages during ripening
Term
the hard part of using time domain reflectometry to determine irrigation needs
Definition
The hard part is keeping the rods parallel; if they bow in or out, that changes the speed of travel
Term
the idea behind gated pipe irrigation
Definition
The idea is that the water in the furrows gets to the plants by lateral flow
Term
the important thing for Radiation Utilization by a Crop Surface
Definition
light interception
Term
the leaves that are first removed by livestock
Definition
the youngest leaves
Term
the light absorption in p'synth
Definition
-light is absorbed by chloroplasts
-photon excites electron
Term
the light requirement of C4 p'synth as oppose to C3 p'synth
Definition
Requires 2x light to fix 1 C
Term
the light rxns that occur in p'synth
Definition

-light absorption

-cyclic and non-cyclic utilization of e-

Term
the major controllers of the photoperiodism response
Definition
Phytochrome A and B
Term
the major phytochrome influences
Definition
phytochromes A and B (analogous to Pred and Pfred), but they interact w/ other forms of phytochrome
Term
the maximum rate that should be irrigated regardless of irrigation method
Definition
never apply more than 0.3 to 0.5 inches per hour
Term
the nighttime sensor system used by plants
Definition
the Pred vs. Pfred interaction of the phytochromes
Term
the path water follows before being transpired
Definition
-taken up by roots
-transported thru plant
-lost thru stomata in leaf as water vapor
Term
the photosystem in which cyclic phosphorylation (photophosphorylation) occurs
Definition
p'system 1
Term
the photosystem in which non-cyclic photophosphorylation occurs
Definition
p'system 2
Term
the photosystems consists of arrays of...
Definition
chlorophyll molecules
Term
the process of post fertilization development
Definition
1: developing seed signals plant for growth stimulus; this is role reversal
2: plant sends nearly all available CHO, protein, and stored energy to seed
3: ethylene production; this leads to senescence
4: senescence
Term
the pros and cons of traveling gun irrigation
Definition
low cost, but not very efficient
Term
the rainfall to pan evaporation relationship that constitutes a water deficit
Definition
when pan evaporation is greater than rainfall
Term
the relationship between temperature and respiration
Definition
curvilinear or parabolic, such that Respiration doubles for every 10°C increase in temperature (between 4 and 36°C) and (doubles for every 18°F between 40 and 97°F); this is known as the Q10
Term
the roles of phytochromes C, D, and E
Definition
to modify the expression of phytochrome A and B, but no one knows exactly how as of yet
Term
the rxn for respiration
Definition
C6H12O6 + 6O2 --> 6H2O + 6CO2 + 673 kcal
Term
the rxn that forms NADPH
Definition
NADP + H+ + e- --> NADPH
Term
the rxns OH- goes thru in non-cyclic photophosphorylation
Definition

4 H2O --> 4 H+ + 4 OH-

4 OH- --> 4 OH+ + 4 e-

4 OH+ --> 2 H2O + O2

Term
the sequence of senescence in pants
Definition
begins at bottom of plant (oldest leaves) and works its way up a stem; makes sense because bottom leaves contribute least to p'synth while top leaves contribute most
Term
the signal sent out by antipodals
Definition
Antipotals send out signals saying don’t come here
Term
the signal sent out by synergids
Definition
Synergids send out signals saying come here
Term
the soil that tends to have the highest infiltration rate
Definition
sand
Term
the soil that tends to have the least available soil water
Definition
sand
Term
the soil that tends to have the lowest infiltration rate
Definition
clay
Term
the soil that tends to have the most available soil water
Definition
clay
Term
the stages of crop development
Definition
1: germination
2: first lag phase
3: log phase
4: linear phase
5: second lag phase
Term
the steps of fertilization in order
Definition
1: pollen grain lands on stigma
2: pollen germinates
3: pollen develops tube
4: tube grows into ovary where it fertilizes the ovule
Term
the strategy behind seed production
Definition
survival of the species (annuals)
Term
the thing in the Calvin cycle that gets sent into the cytoplasm and converted into glucose
Definition
G3P
Term
the things involved in photoperiodism
Definition
5 phytochromes and at least 2 forms of cryptochromes (sense blue light). Not clear on how they interact at this time.
Term
the things that happen in the light rxns in p'synthesis
Definition

-p'system 2 obtains electrons by splitting water

-light striking the p'systems excites the electrons

-these electrons go down the electron transport chain to p'system 1, attracting H+ ions along the way

-light striking the p'system excites the electrons

-the electrons go down an electron transport chain and get added to NADP+ to form NADPH

-the H+ ions in the thylakoid compartment go down their c'tration gradient thru an enzyme called ATP synthase to generate ATP

Term
the tissue C3 p'synth is found in
Definition
all leaf parenchyma tissue
Term
the true day/night interaction in plants
Definition
the one between phytochromes (the night time sensor system) and cryptochromes (the day time sensor system)
Term
the type of center pivot irrigation system that's about 30% more efficient
Definition
the more modern low pressure system that's low and close to the plant surface; more efficient than high pressure that's high and far from the plant surface
Term
the type of response fertilization in flowers is
Definition
chemotaxic
Term
the type of response floral induction is
Definition
a temperature response
Term
the type of response floral initiation is
Definition
light response
Term
the type of response that occurs after pollen grain lands on stigma
Definition
chemotaxic response
Term
the type of response that the phytochrome vs. cryptochrome response is
Definition
speculation is that this is one of auxin (phytochrome) and gibberellin (cryptochrome)
Term
the type of rxn C3 p'synth is
Definition
reduction rxn
Term
the types of pores in clays
Definition
Clay has lotta micropores
Term
the use of drip irrigation in row crops
Definition
Not used in row crops very much, but could be useful
Term
the w'length used in cyclic phosphorylation (photophosphorylation)
Definition
760nm
Term
the weed that's the biggest problem
Definition
Palmer amaranth
Term
theory of optimal LAI
Definition
occurs in crops where leaves lay flat (level to the soil and perpendicular to the sun), shade others which become parasitic (turns out this is bogus!)
Term
these 2 things interact to trigger flowering
Definition
light and temp
Term
these 3 SE states have conflict over water for irrigation
Definition
There’s conflict between AL, GA, and FL for that water for irrigation
Term
these control the aperature on the stomata
Definition
guard cells
Term
these interact to promote flowering
Definition
light and temperature
Term
things that affect pollination in linear phase
Definition
-heat
-drought
Term
things that can cause flower drop in soybeans
Definition
may be in response to drought or related to amount of energy available from the plant to fill seed during maturation
Term
things that happen in senescence
Definition
-leaves translocate metabolites (proteins, CHO) to seeds and become functionless
-begins at bottom of plant (oldest leaves) and works its way up a stem; makes sense because bottom leaves contribute least to p'synth while top leaves contribute most
-irreversable
Term
things that may cause flower drop
Definition
-may be in response to drought
-may be related to amount of energy available from the plant to fill the seed during maturation
Term
this color light doesn't have all its energy used to excite an electron
Definition
blue
Term
this develops into embryo proper
Definition
terminal cell
Term
this develops into suspensor
Definition
basal cell
Term
this governs crop yield when water and nutrients aren't limiting
Definition
solar radiation
Term
this happens in the second lag phase
Definition
-grain fill continues
-remobilization of energy from leaves to seed
Term
this is critical late in the linear phase of crop development
Definition
leaf area duration
Term
this is probably the most efficient form of irrigation
Definition
drip irrigation (close to 100%)
Term
this keeps the soil from heating and in turn heating the atmosphere
Definition
evaporation
Term
this kills developing embryo in linear phase
Definition
frost
Term
this leads to insufficient GA production
Definition
insufficient water and nutrients
Term
this must occur before terminal spike begins to develop
Definition
vernalization
Term
this reduces crop quality in the second lag phase
Definition
disease
Term
this regarding the hormones causes the things to occur
Definition
the interaction of the hormones
Term
this w'length light doesn't have all its energy used to excite an electron
Definition
400nm
Term
timing of flowering of plants with double recessive phy a and phy bcompared to plants with recessive phy b and dominant phy A
Definition
plants with double recessive phy a and phy b will flower earlier than plants with the recessive phy b and dominant phy A

no one knows why, but this is being researched
Term
to evaluate Light Interception and Use, we must examine...
Definition
-Total area of leaves
-Efficiency of the canopy
-Modifications of leaf area and efficiency (disease, insect, weed competition)
-Duration leaf remains on the plant (leaf area duration)
-Day and season length
Term
transpiration
Definition
water lost from crop surfaces

this is a plant process
Term
transpiration ratio
Definition
# of lbs of water to produce 1 lb of dry plant
Term
transpiration ratio (TR)
Definition
TR= weight of water used to grow a unit weight of plant
Term
transpiration ratio (TR) can be used to measure...
Definition
efficiency
Term
transpiration ratio changes with ______ because of...
Definition
climate
changes in temp, relative humidity, and wind
Term
transport of CO2 is affected by...
Definition
stomatal opening
Term
traveling gun irrigation better for...
Definition
small areas
Term
types of germination
Definition
-epigeal
-hypogeal
Term
under field conditions, this usually limits p'synth
Definition
light intensity and CO2 c'tration
Term
under high light and high CO2, this limits p'synth
Definition
temperature, that is, it limits the biochem processes associated with CO2 fixation
Term
under low light, this limits p'synth
Definition
p'systems
Term
under normal conditions, this limits p'synth
Definition
c'trtration of atmospheric CO2 limits the diffusion of CO2 into plants and limits PS
Term
underlying principle of the heat unit concept
Definition
so long as temp does not reach a critical max or min and cause plant death, crop events can be predicted within a crop season
Term
under normal conditions, this controls the diffusion rate of CO2
Definition
the c'tration of CO2 on the outside of the plant
Term
vernalization
Definition
I think this is the initiation of flowering
Term
vernalization must occur before this begins to develop
Definition
terminal spike
Term
w'length for Pfred phytochrome
Definition
730 nm
Term
w'length for Pred phytochrome
Definition
660 nm
Term
water use efficiency (WUE)
Definition
amount of water used per unit of yield (grain, fiber, forage)
Term
weaknesses of using soil moisture blocks for determining irrigation needs
Definition
-Must calibrate for each soil
-Does not account for soil variability
-Multiple blocks per system
-Expensive
Term
weather in which C4 p'synth does better
Definition
warmer weather
Term
weight gain in C3 crops vs. weight gain in C4 crops
Definition
C4 crops gain weight faster and at higher temps than C3 crops
Term
what C3 plants and C3 plants only do when there's more O2 relative to CO2
Definition
go from p'synth to respiration
Term
what C4 cells do with C3 cells inside a plant
Definition
C4 cells feed malate to the C3 cells so the C3 cells have adequate CO2
Term
what Double fertilization of plant ovules leads to
Definition
diploid and triploid tissue
Term
what abscisic acid aka dormin promotes
Definition
bud and seed dormancy
Term
what abscisic acid does in plants
Definition
-Promotes dormancy in seed
-Inhibits bud growth
-Promotes leaf drop
Term
what circular pastures are sectioned off into
Definition
paddocks
Term
what disease does in the second lag phase
Definition
reduces crop quality
Term
what do the negative numbers mean on the map of the center pivot irrigation system?
Definition
the positive amount of surplus, which means the pores in the soil are getting saturated; all the numbers indicate how much water needs to be added
Term
what drought affects during linear phase
Definition
pollination
Term
what ethylene can be used for
Definition
-we can use this to control fruit ripening
-Sometimes, you get fruit with this paper on it that has ethylene to keep it from ripening
Term
what ethylene does in pants
Definition
-Promotes maturation
-Produced in all tissues
+Embryos in seed
+Fruit (banana/apple example)
Term
what ethylene production leads to
Definition
senescence
Term
what gibberellins promote
Definition
-stem elongation
-seed germination
-fruit set (after pollination)
Term
what giberellic acid can be used for
Definition
-we can spray this on grapes to make grapes seedless
-Rize-up: GA that’s spread onto pastures that got ryegrass such that the grass is primed to continue growing
Term
what happens after fertilization in order
Definition
1: post fertilization development
2: grain fill
3: dry weight accumulation in plant
Term
what happens to energy in p'synth?
Definition
gets harvested and sent to granum
Term
what happens to the ATP and NADPH generated in the light rxns?
Definition
they're used in the sugar making process of the Calvin cycle
Term
what happens to the H+ in C3 p'synth
Definition

-energy stored as H+ transferred to CHO

-H+ is stored when glucose or starch is formed

Term
what happens to the H+ int the thylakoid compartment?
Definition
they go down their c'tration gradient thru an enzyme called ATP synthase to generate ATP
Term
what happens to the electrons in non-cyclic photophosphorylation?
Definition
1 electron goes back to p'system 1 and the other 3 generate ATP
Term
what happens to the electrons in p'system 1?
Definition
they are passed down an electron transport chain and added to NADP+ to form NADPH
Term
what happens to the electrons in p'system 2?
Definition
passed thru another electron transport chain, then used to replenish the electrons in p'system 1
Term
what happens to the energy in the light rxns in p'synth?
Definition
The energy funneled down into the granum splits the water and HNADP gets converted to NADPH
Term
what happens when we hydrate clays?
Definition
they hydrate and expand
Term
what has happened to the amount of crop land we irrigate from 1994 to 2010?
Definition
From 1994-2010, the amount of crop land we irrigate has increased 72%, mostly in S. GA, particularly SW GA
Term
what heat affects during linear phase
Definition
pollination
Term
what knowing the cardinal temperatures allows us to do
Definition
knowing the cardinal temperatures allows us to calculate how much heat has accumulated in the crop's life and predict its stage of development using the heat unit system
Term
what light does in the photosystems
Definition
excites the electrons in there
Term
what phytochromes A and B are needed for
Definition
regulation of the time of flowering, but neither is responsible for induction or repression of flowering as previously thought
Term
what pollen does after it lands on the flower
Definition
Pollen drops onto the stigma, eventually fertilizing egg
Term
what pollen grain does after landing on stigma in order
Definition
-germinates
-develops a tube
-grows into ovary where it fertilizes the ovules
Term
what pollen tubes do in flowers
Definition
develop from germinating pollen and deliver male gametes to ovule
Term
what short day means as in short day crops
Definition
responds to when the days are getting shorter
Term
what the computer in the manager's office shows regarding center pivot irrigation
Definition
map of the field showing the soil types, locations of soil monitoring stations, and amount of water needed to apply to the soil to reach 90% of available soil water
Term
what the energy of the electrons in p'system 2 are used for
Definition
to pump H+ ions from the stroma into the thylakoid compartment, creating a c'tration gradient
Term
what the energy of the sunlight on the soil can do
Definition
Sufficient energy falling on 1 m2 over the course of the year to supply house with energy for 1 year
Term
what the kcal in the respiration rxn can be used for
Definition
the growth and development of the plant
Term
what too much shading does to grain crops
Definition
forces more energy to stalk and less energy to seed
Term
what transpiration ratio can be used for
Definition
can be used to evaluate water use efficiency
Term
what treatment of seeds w/ ethylene (ethephon) results in
Definition
more uniform germination of seeds
Term
what we need in order to solve the irrigation water problem
Definition
more efficient systems
Term
what would happen if we removed the tassel in corn w/o ears and why?
Definition
ear develops

because ps would normally go to tassel and ear; if we remove tassel, ps goes to meristems and ear develops
Term
what you must know to predict crop water needs
Definition
the water requirements for the crop by stage of development
Term
what's been happening with the amount of irrigated land vs. what's been happening with population growth
Definition
The amount of our irrigated land is increasing faster than our population is increasing; demand for food has been increasing
Term
when C3 plants and C3 plants only go from p'synth to respiration
Definition
when there's more O2 relative to CO2
Term
when evaporation is important for crops
Definition
when crop is young and leaf surface not yet developed over soil surface (low LAI)
Term
when irrigation is essential
Definition
when natural rainfall is insufficient or untimely
Term
when light is this color, there is almost no absorption of light and therefore energy not used to excite electron
Definition
green
Term
when plants do the grain fill process
Definition
after fertilization
Term
when seed set occurs
Definition
after pollination but before fertilization of ovaries
Term
when solar radiation governs crop yield
Definition
when water and nutrients aren't limiting
Term
when the phytochrome is Pfred (P far red)
Definition
night
Term
when the phytochrome is Pred (P red)
Definition
day
Term
when vernalization must occur
Definition
before terminal spike begins to develop
Term
when you have the greatest water use efficiency (WUE)
Definition
when you have critical leaf index (I think)
Term
when you're irrigating, any time you're over this rate, you have water running off the surface
Definition
the intake rate
Term
where C3 p'synth is found
Definition
all leaf parenchyma tissue
Term
where RUDP CO~ase is found
Definition
in mesophyll of C3 and only in bundle sheath of C4
Term
where abscisic acid is produced
Definition
all plant parts
Term
where dark rxns occur
Definition
in the stroma of the chloroplast
Term
where ethylene is produced
Definition
in all plant tissues
Term
where gated pipe irrigation is fairly common
Definition
out west
Term
where seeds accumulate nutrients
Definition
endosperm or cotyledons
Term
where the Calvin cycle happens
Definition
in the stroma of the chloroplast
Term
where the dark rxns occur in C3 plants
Definition
the mesophyll
Term
where the light rxns in p'synth occur
Definition
thylakoid membrane
Term
where you can find Georgia weather information
Definition
www.griffin.peachnet.edu/bae/
Term
which age tissue does more respiration?
Definition
the young tissue
Term
why C3 p'synthesis is called C3
Definition
because the 3 C thing is the first stable compound in here
Term
why C4 p'synth is called C4
Definition
because the first stable compound is the 4C oxalic acid compound
Term
why C4 plants are more efficient with hater (higher WUE)
Definition
because C4 plants have no photorespiration; therefore, more efficient
Term
why C4 plants have a higher CO2 compensation point than C3 plants
Definition
The reason for this in C4 plants is because of C saturation or something like that
Term
why PS occurs longer in corn than in soybeans in full sun
Definition
because the CO2 compensation point of corn (a C4 plant) is lower than that of soybeans (a C3 plant)
Term
why cold is required for some crops
Definition
some crops have a cold requirement to induce vernalization; this is independent of photoperiod
Term
why corn is used for feed instead of barley
Definition
because corn is more water efficient
Term
why crop yield can become reduced as a result of too much moisture
Definition
because of lack of oxygen to roots
Term
why energy efficiency of p'synth is low at 400nm blue light
Definition
because not all the energy is used to excite the electron and one photon is capable of exciting only 1 electron
Term
why environmental or pest stresses affect the crop differently
Definition
because different events are occurring within the plant's growth stage
Term
why heat is a driving force in crop growth and development
Definition
because each crop has a minimum temp it needs to be p’synth active and put on weight
Term
why increase in biological yield is not linear
Definition
because of competition between plants; each plant yields less, but cumulatively yields more
Term
why it's important to know critical LAI
Definition
so you can make management decisions regarding seeding rate and configuration
Term
why it's important to understand the relationships between auxin and cytokinin
Definition
very important for genetic engineering of plants/plant cloning.
Term
why late spring planting leads to fewer seeds
Definition
shorter days, which lead to less ps, which lead to CHO for reproduction
Term
why leaves roll, droop, or scenesce during drought
Definition
plants attempt to escape drought by reducing evaporative surface and/or limiting exposure of stomata to air
Term
why light at w'length 760nm is good for p'synth
Definition
because the proportion of energy converted is high because little energy is left over after electron excitation
Term
why low pressure center pivot irrigation is more efficient than high pressure center pivot irrigation
Definition
less evaporation due to being closer to the crop surface
Term
why p'synth ceases before wilting
Definition
stomata close as the plant becomes less turgid
Term
why plant breeders have effectively eliminated ABA
Definition
so that the following crop can be easily planted
Term
why plant leaves are green
Definition
because when there's green light (525nm), there is almost no absorption of light and therefore energy not used to excite electron
Term
why scientists developed crop growth models
Definition
to predict the stage of development a crop is in at any time
Term
why the plant prioritizes young tissue
Definition
because that’s where the new growth comes from
Term
why the true day/night interaction is one between phytochrome and cryptochrome
Definition
because the blue light sensory system of cryptochromes is a day length sensor in the plants
Term
why there's fewer seeds per plant at higher density
Definition
decreased light penetration in canopy causes insufficient supply of p'synthate to reproductive regions to develop reproductive parts
Term
why use crop growth models
Definition
they can be used as a management aid
Term
why use crop models?
Definition
Management aid (helps predict impact of catastrophic events and such)
Term
why water is a perfect mechanism for dissipating heat in plants
Definition
Water mixes readily, so heat moves from one area in liquid to another very easily. Therefore, if we are evaporating water from a leaf surface, the water (and leaf) is cooled according to how much is evaporated from the leaf surface.
Term
within a plant, you have this regarding hormones
Definition
gradients of hormones
Term
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Definition
high pressure center pivot irrigation
Term
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Definition
drip irrigation
Term
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Definition
low pressure center pivot irrigation
Term
[image]
Definition
gated pipe irrigation
Term
[image]
Definition
traveling gun irrigation
Term
[image]
Definition
solid set irrigation
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