UNIT
4: LESSON 1
RATE THAT TRAIT
SUBJECT:
Math
OBJECTIVE:
Students will learn some of the criteria used by farmers to
select corn hybrids, and will use numerical ratings to guide their selections,
just as farmers do.
MEASUREMENT:
Students will be able to use numerical ratings to compare traits of
different corn hybrids.
BACKGROUND FOR
TEACHERS:
In the 1930s an
important advance in corn production was made, called hybrid development.
Hybrids can be bred for specific characteristics such as yield, stalk
or root strength, resistance to insects or disease, tolerance to particular
soil or climatic conditions, and much more. Today, there are thousands
of hybrids to choose from, and those numbers continue to grow.
Proper hybrid selection
is a challenge for farmers. There are few decisions as crucial in determining
the health and yield of a cornfield, but it is an increasingly complicated
and difficult decision. To aid in this selection, seed companies rate
their hybrids, and pass that information on to farmers. Rating systems
vary from company to company, but all attempt to list the traits a farmer
looks for, and then rank each hybrid according to its performance for
that specific trait.
STUDENT ACTIVITIES:
1. Ask students
to read the story Elizabeth Learns Why She Has
Blue Eyes, and ask them to think about some of the traits she described
in corn-taller, sweeter, more nutritious, resistant to insects, etc.
Ask them to imagine other traits that could affect corn plants.
2. Use Worksheet
1 to complete the following exercises:
- Younger students
can be asked questions which can be answered by looking at which numbers
are the highest or lowest. For example: Which corn hybrid has the
strongest roots? Which plant is the tallest? Which one is most resistant
to Northern corn leaf blight, or European corn borer? Which one has
the highest Relative Maturity rating (in other words, which one needs
the longest season to mature)?
- Younger students
could also be asked to graph the values from one or more columns on
graph paper, and color it.
- They could also
be asked to pick a particular hybrid and draw a picture of it, based
on the traits that are most significant.
- Older students
can be split into teams of two; one student is the "farmer" and the
other is the "seed salesperson." Ask the farmer to place an order,
asking questions about specific hybrid traits. The salesman should
be able to answer the questions using the numeric ratings given.
- Older students
can also be asked to average the values for one or more of the traits.
They could also enter this information into a computer spreadsheet
from which they could create charts and graphs.
- Older students
can also be asked to calculate percentages; for example, what percentage
of these hybrids has a Relative Maturity over 95 days?
