A physiological method of improving seed performance is
known as seed priming. In seed priming, the basic
reactions needed for the seed to
germinate occur in a lab under high moisture and ideal
The water supplied to the seed
is controlled such that seed moistures are at a level
just below what is needed for actual germination, but
just enough to get the process going. Germination is
subsequently temporarily arrested by drying the seeds,
allowing them to be packaged, distributed and planted in
the same way as untreated seeds.
Primed seed usually
results in more rapid and uniform emergence of seedlings
from the soil compared to non-primed seed of the same
These differences are greatest under adverse
environmental conditions in the field, such as cold or
In addition, priming can overcome some types
of environmental stresses, such as high temperature
inhibition of lettuce seed germination.
often has a shorter life span than non-primed seed, and
should be stored under optimal conditions prior to
However, further refinements of the priming
process, particularly the handling of the seeds prior to
dehydration, are able to mitigate this effect.