Lecture 1- plant physiology Flashcards
what do plants need to grow
CO2
primary function of roots
aquisition of soil based resources (water and ions)
anchoring plants
secondary functions of roots
storage
synthesis of hormones
propogation
some stats on roots - mass %
soil volume
40% of mass
5% of soil volume
shape and depth determined by
genetics
growth and distribution governed by
soil moisture .soil temp profile o2 toxins nutrients
root tips will grow in what direction
positive moisture gradient
what do the root tips produce during water stress
abscissic acid
what does abscissic acid do and where is it produced
root tips, it closes the stomata
three purposes of stems
display leaves to light
transport from roots to leaves
sometimes storage of water food etc
purpose of flowers/fruit
reproduction and storage
write the photosynthesis equation
ok
more stomata on underside or top
more on underside (lower evap on bottom side so have more)
when do stomata open or close
depends on water content and humidity
how do stomata open and close
concentration of K changes (potassium ) -get flow of water into cells (opens)
out of cell (closes)
what is crop development, crop growth, and how does the latter occur
development- progress from germination to maturity
growth- increase in size- due to new cells
- expansion of cells
- production of assimilates
what are the 7 development stages
seeding germination emergence vegetative stage reproductive phase ripening phase harvest
what are the four phases to the development of a seedling
imbibition -absorption of water
breaking of seed coat
first root
first leaf
what is the vegetative phase
green leaves+ photsynthesis= dry matter production
what does the rate of photosynthesis depend on
irradiance
co2 concentration
temperature
water status
reproductive phase
flowering
pollination
fruit setting
maturity
growth rate stages
lag period from sowing exponential linear zero negativeq
2 main and other influences on growth rate
temp
photoperiod
light c02 nutrients toxins water
what are the ranges for base temp, optimum temo, and max temp
0-5 base
20-25 optimum
35-45 max
what is the thermal period
amount of time T between base and max limits
how does the photoperiod effect growth
photosynthesis
induction of flowering
suitability for growing outside normal zone
draw how the rates of photosythesis changes for varying light intenisty, and vary temp (two light intensities)
ok
how does c02 affect growth
reduction in stomatal conductance
improve water use efficiency
higher photo synth rates
increased light use efficiency
what is defined as the rate that co2 enters the stomata
stomatal conductance
what are some macro nutrients
C H O
N P K
ca mg S
micro nutrients
fe ma cu zn B cl
draw graph of nutrient effect on growth
ok
nutrient uptake dependent on
how is absorbed
nutrient avalability in soil
nutrient aquisition of plant
liquid phase only
what is the soil nutrient supply dependent on
soil solution concentration soil buffer power soil water holding capacity soil bulk density soil temperature
5 roles of water in the plant
photosysnthesis control temp structural support transport of gases makes up organs
what is crop water use broken up into
99%transpiration
1% tissue
