The United States
Letters from Thomas Jefferson
document his trials with sesame between 1808 and 1824. Jefferson stated
that sesame "
is among the most valuable acquisitions our
country has ever made
. I do not believe before that there exists
so perfect a substitute for olive oil." (1)
Sesame did not become a viable
crop in the United States, however, until the middle of the last century
when it was produced in West Texas. Production was highly labor intensive
and, as labor costs rose, the sesame crop disappeared.
Except for what you see described
in this website and related websites, sesame production throughout the
world today is still highly labor intensive and, therefore, restricted
to developing countries.
The sesame plant demands
that this be so. As the plant matures in the field, the capsules holding
the seeds dry, open and the seeds fall to the ground. Losses can be
30% or as high as 100% in bad weather. Varieties that break open like
this are known as dehiscent.
In order to grow these dehiscent
sesame varieties, the plant must be cut by hand when it is still green
and placed in shocks to dry. When dry, the seed is shaken from the capsules,
as shown in the picture below. Swathing is sometimes used as are basic
hand threshers, but the process still requires considerable labor.
However, through years of
traditional plant breeding, sesame varieties in the United States have
been developed with the characteristic that, now, as the plants dry
in the field, the capsules continue to hold the seeds and the seeds
are protected from loss. These varieties are known as non-dehiscent
As shown in the picture below
at the left, as the plant begins to dry the capsules of the dehiscent
varieties open, exposing the seed to loss. Conversely, as the non-dehiscent
varieties dry, the capsule remains sufficiently but not totally closed,
as shown in the picture below at the right. There is enough of an opening
to release moisture and to ensure that the combine can open the capsule
and release the seed as it is harvested.
With these new varieties,
sesame has again become a valuable crop grown in the United States.
Non-dehiscent varieties allow the plant to dry standing in the field
like sorghum or wheat or corn or soybeans. It can be harvested with
standard combines, as shown below, and cleaned and stored with standard
grain handling equipment.
Sesame can now be a major
alternative field crop for the American farmer.
Non-dehiscent is defined
as "adapted for mechanical harvesting with minimal loss."
(1) Betts, E.M.
1999, Thomas Jefferson's garden book (1766-1824) Thomas Jefferson Memorial
Floundation, Inc., Chalottesville, VA.