a state of inactive growth.
- to survive adverse conditions.
TYPES OF DORMANCY
- dormancy imposed by external or environmental conditions
or Physiological Dormancy - dormancy imposed by internal or
a) Unfavorable environmental
b) External factor,
such as hard seed coat
too dry, cold, hot, etc.
Remove unfavorable environment
a) short days (SD)
b) decreasing temperatures
Internal physiology is unfavorable:
a) low level of growth
promoters (e.g. auxin or gibberellic acid), and/or
b) high level of
growth inhibitors (e.g. ABA)
Give period of cold between
32-45 oF (0-7 oC), which satisfies the chilling requirement.
the number of hours of cold between 32-45 oF (0-7 oC)
required to satisfy rest.