Absorption
To understand the methods for reducing transpiration, as proposed in
this chapter, it is necessary to review briefly the manner in which
plants take water from the soil. The roots are the organs of water
absorption. Practically no water is taken into the plants by the
stems or leaves, even under conditions of heavy rainfall. Such small
quantities as may enter the plant through the stems and leaves are
of very little value in furthering the life and growth of the plant.
The roots alone are of real consequence in water absorption. All
parts of the roots do not possess equal power of taking up
soil-water. In the process of water absorption the younger roots are
most active and effective. Even of the young roots, however, only
certain parts are actively engaged in water absorption. At the very
tips of the young growing roots are numerous fine hairs. These
root-hairs, which cluster about the growing point of the young
roots, are the organs of the plant that absorb soil-water. They are
of value only for limited periods of time, for as they grow older,
they lose their power of water absorption.
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