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