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Plumule helps with
black layers shows
that the seed is fully mature
when the seed coat can't easily be separated from the seed, what is that called?
caryopsis (think corn)
when the seed coat can be pulled easily, it's a testa. What is a drawback?
Soil organisms can get through easier
cotyledons - difference between grass and legume family?
grass has one, legume has two
differences between food supply locations in grass and legume?
- Food supply in the grass is in the endosperm
- Food supply in the legume is in the cotyledons
food supply type for grasses?
food supply type for legumes?
protein and oil
function of cotyledons for grasses?
function of cotyledons for legumes?
is coleoptile present in grass, legume or both?
grass - it's responsible for first emergence
is coleorhiza present in grass, legume or both?
- it protects the radicle
hypocotyl active in grass, legume or both?
legume - stem of germinating seed, under cotyledons
epicotyl in the grass is called the
mesocotyl (it's below ground, between adventitious root and secondary root)
epicotyl in legume does what?
emergence - it's between first leaves and cotyledons
pollination leads to sugars in the endosperm
what are some advantages of hypogeal over epigeal emergence?
- First - hypo (below) geal (earth)
- grasses do this
- takes less energy for emergence
- can plant deeper
- frost protection
describe epigeal emergence and what types of plants use this?
- epi (above) geal (soil)
- cotyledons are above the soil after emergence
- legumes do this
- it's energetically difficult for plants to do this
what's a bad time to drive a tractor through the field when your soybeans are in the ground?
during hypocotyl hook emergence
how do first leaves look on cotyledons v. grasses?
- leaves on cotyledons are opposite
- grasses are in a whorl
Wheat yield calculation
- no. grain/head * no. heads * 0.027 (sm/med) divided by row spacing in cm
- this is within a meter
things that may affect wheat yield estimates
- maturity of crop (water enough to finish?)
- condition of grains
once the black layer is down, its dry matter is
complete. not going to gain more.
what can make seeds sprout on the plant?
what is the point of attachment?
what gets the cotyledon above the soil?
what part of the seed is first to grow?
how does pollen enter the embryo?
through the micropyle
three cotyledon functions?
- gas tank
- photosynthesis once emerged
- protection of embryo
what is a function of the cotyledon in a caryopsis?
enzymatic activity - absorbs carbs to grow
secondary roots are also called
- seminal roots
- these are roots growing in the area of the seeds
what tells the coleoptile (this pierces the ground and carries the plumule inside) to stop growing?
meso means what?
- the mesocotyl connects the seed to the first node underground (the seed is below it, the adventitious root is above)
what should you look for when buying seed?
discolored, misshapen, cracks, weed seed
where does water usually enter the seed?
micropyle or hilum - can also penetrate seed coat
what water requirements are needed for germination?
sorghum and corn the least (26-30 percent), soybeans the most (75 percent) 45-50 for small grains
what begins the use of stored energy?
- enzyme activation (this is temp related)
- water - giberellic acid - enzyme (amalyse) starts converting starches to sugar
total requirements for germination?
water - enzyme activation - oxygen - temperature
general rule, how much does temperature speed up germination for each 10 C?
two to three times
what crop has lowest minimum germination temp?
what crop has highest minimum temp for germination?
- rice and sorghum (70 F)
- Pearl millet (64)
low temp requirement that must be met for flowering to occur
what stimulates wheat tillering and leaf formatin?
short photoperiod (day length) and warm temps
kernels per bushel estimates for corn?
- 90,000 medium
- 80,000 large
- 100,000 smaller than usual
kernels per kilogram corn yields?
- 3500 medium
- 4300 small
- 3100 large