Lab 4: Baby Plants
Rachel Veenstra 
AGRON 220 Lab: Baby Plants
A worksheet to walk you through the fourth lab session
Task 1: Label key seed components on the diagrams below. You may use words, arrows, or colors in your diagram.
Plumule
Radicle
Cotyledon
Seed Coat
Hypocotyl
Coleoptile
Coleorhiza
Endosperm
Pericarp
Hilum
Task 2: Dissect the water-soaked seeds you are given. Check off key features as you find them and answer the provided questions. Have an instructor check your identification and answers before moving on.
Cowpea
Corn
Sunflower
Peel off seed coat and split the cotyledons apart at the seam with your fingernail.
Find the following:
Plumule
Radicle
Cotyledons
The radicle becomes the
The plumule becomes the
Because cowpea has
cotyledon(s), it is a
Carefully using a razor blade, cut the corn seed lenthwise.
Find the following:
Endosperm
Plumule
Cotyledon(s)
The coleorhiza protects the
The coleoptile protects the
Because the pericarp is fused, this NOT a true seed but instead a
Because corn has
cotyledon(s), it is a
Split the sunflower achene apart at the seam with your fingernail.
Find the following:
Pericarp
Seed coat
Cotyledon(s)
Because the sunflower has
cotyledon(s), it is a
Task 3: Label the key parts of these soybean and corn seedlings. You may use words, colors, or arrows in your diagrams.
Radicle
Hypocotyl hook
Epicotyl
Cotyledon
Plumule
Hypocotyl
First true leaf
Cotyledonary node
Radicle
Coleoptile
First true leaf
Primary root
Mesocotyl
Seminal roots
Crown roots
TO THE GREENHOUSE! Retreive the plants with your group number on them from the greenhouse.
Task 4: Carefully dig up your seedlings, clean the roots, and lay them side by side. Take a picture and label key parts (from above) on your iPad. Airdrop the picture to your instructor when you finish. Answer these questions:
Which seedlings have epigeal emergence?
Which seedlings have hypogeal emergence
Which shoots were pushed to the surface by a mesocotyl?
Which shoots were pushed to the surface by a hypocotyl?
How many total cotyledons are visible on your seedlings?
Which seedlings could grow back after being cut off at *soil level*?
Which seedling is your group's favorite and why?
Task 5: List 1-2 pros and cons to the strategy corn and soybeans take for emerging (epigeal vs hypogeal).
Soybean pros
Soybean cons
Corn pros
Corn cons
Task 5: Complete the following farmer problems.
Check out the germination trays we have on display at STATION #1.
Pick a tray and count
1) the number of seeds that were tested and
2) the number of seeds that germinated.
What percentage of these crop seeds will germinate?
Show us how you got your answer.
Space to think - draw or write thoughts here
Germination %
Calculation
You are planting soybeans and targeting 130,000 plants per acre. After a germination test, you know that only 85% of the soybean seeds you plant will actually germinate.
How many seeds should be planted per acre to achieve the right number of plants per acre?
Show us how you got your answer. (hint: seed number will always be more than the final plant number)
Space to think - draw or write thoughts here
Calculation
Seeds per acre
Observe the 3 seedling trays at STATION #2. It is obvious that spacing between seeds is not uniform. Maybe we need new equipment! There were some germination/emergence problems too.
Why might germination/emergence not be even in a field?
Reason 1.
Reason 2.
Reason 3.
Check out the 3 seedling trays at STATION #2. Calculate the area of "field" in each tray, count the seedlings, and determine the plants per acre.
Your final answers should be plants per acre.
Include the unit cancellation for how you got your answer!
Space to think - draw or write thoughts here
Calculations
Tray 1 Crop
1 - Plants per acre
Tray 2 Crop
2 - Plants per acre
Tray 3 Crop
3 - Plants per acre
Pick two of the trays from STATION #2.
Determine the space (in inches) that should be between seeds if the planter had worked perfectly and both germination and emergence were 100%.
Soybean and wheat row spacing: 7.5 inches
Corn row spacing: 15 inches
Acre: 43,560 sq ft
Space to think - draw or write thoughts here
Calculation (first tray)
Inches per seed
Calculation (second tray)
Inches per seed
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