Crop Production Lab 5&6

Cotyledon Function

embryonic leaves, provide essential nutrients and support the developing plant

epigeal emergence

(active hypocotyl emergence) the hypocotyl elongates to form the hypocotyl arch (below the first node) this pulls the cotyledons above the ground (Epigeal emergence)

hypogeal emergence

(active epigeal emergence) cotyledons remain below ground where planted

crops that exhibit epigeal emergence

soybean, cowpea, common bean, and small-seeded legumes

hypogeal emergence

all grasses, peas, vetches, chickpea, lentils

mesocotyls

first internode above the scutellar node

coleoptiles

sheath that encloses and protects the plumule (embryonic shoot)

panicoid emergence

elongating mesocotyl and coleoptile, they elongate simultaneously to facilitate seedling emergence. examples include: corn, sorghum, and warm season grasses

festucoid emergence

elongating coleoptile, the mesocotyl does not elongate, rather the second internode elongates. examples include wheat, barley, and cool season grasses. 

what does a seed need to germinate

oxygen, water, and adequate temperature

Which typer of germination is most susceptible to a killing frost?

epigeal

What does the blower do?

separates the chaff, dust, and light inert matter from the heavier seeds

what does the divider do?

serves as a tool to accurately divide seed samples into smaller portions for analysis

What is and Why is a purity test conducted?

This test is run to let the producer know how much of the sample is not the intended crop seed. The sample is sorted into inert matter, weed seeds, other crop seeds, and the pure seed. 

What is and Why is a germination test conducted?

Four replicates of 100 seeds are germinated. This test shows the estimated germination conditions, such as how many viable seeds there are, how many seeds germinate abnormally, and how many dead seeds there are. 

What is and Why is a tetrazolium test conducted?

This test is an accurate means to determine if the seed is alive or dead. This test takes only 24 hours to get results and is rapid compared to germination tests which take 7-28 days. 

What is and Why is a HPLC or electrophoresis test conducted?

This test is used to determine variety identification/verification.

What needs to be on a seed label in order to be sold in SD?

Name and address of seller, the lot number (if any), kind or variety, percent pure seed, percent inert matter, percent other crops, percent weed seed, name and rate of any restricted noxious weed seeds, percent germination, and the date of the germination test. 

What disqualifies a sample from being sold?

Any prohibited noxious weed seed present, and/or more than 2% of weed seed

This is an example of a(n) type of germination

abnormal germination

This is an example of a(n) type of germination

dead seed (no germination)

This is an example of a(n) type of germination

Viable Seed