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Section 4 Technological Contexts
Other crops use different harvesting
machines. A combine or a special corn-
picking machine can harvest corn.
Mechanical pickers are used to harvest
almost all cotton grown in the United
States. Vegetables can be harvested by
special-purpose machines or by hand.
See Figure 19-19. Special machines dig
and collect onions and potatoes. See
Figure 19-20. Fruits are usually picked
by hand and placed in boxes. Special
machines can, however, be used. They
shake the trees, causing the fruit to fall
into raised catching frames. Nuts are also
harvested in this manner.
A series of machines harvest hay. A
mover might cut the plants and let them fall
on the ground. After the hay has dried for
a day or more, a rake is used to gather it
into windrows (bands of hay). In other cases,
a windrower, or swather, might be used.
This machine cuts and windrows the hay in
one pass over the field. See Figure 19-21.
After the hay has dried, it is usually baled. A
hay baler picks up a windrow and conveys
it into a baling chamber. There, the hay is
compressed into a cube. Wire or twine is tied
around the cube to maintain its shape. The
Figure 19-18. This combine is harvesting grain on a hillside. The header (cutting area) is at the same
angle as the hillside. The machine itself, however, is kept level. This is necessary to make the grain
separation efficient. (Deere and Company)
Figure 19-19. This special-purpose machine
harvests green beans. The machine is unloading a
batch into a truck. The truck will move the beans to
a freezing plant.