Principles of seed propagation and dormancy

What are the three phases of seed development?

Imbibition, Lag phase, Radicle protrusion.

What is seed dormancy?

A condition in which seeds will not germinate even when environmental conditions are favorable.

What are the two types of seed dormancy?

Primary dormancy and Secondary dormancy.

What are the 5 types of primary dormancy?

Physical, chemical, morphological, physiological, and double dormancy.

What is physical dormancy (PY)?

A condition where the seed coat is very hard and dense, preventing water penetration.

What are 5 ways physical dormancy be overcome?

Use sandpaper, hot water, tumbling with rocks, sulfuric acid, or drilling a hole into the seed coat.

What is chemical dormancy (CD)?

A condition where chemicals that act as germination inhibitors accumulate in fruit and seed-covering tissues.

What treatment is best for overcoming chemical dormancy?

Cold stratification for 2-3 months

What is morphological dormancy (MD)?

A condition where the embryo is less than half the size of the seed when shed from the plant.

What are 2 ways morphological dormancy be addressed?

Cold stratification or direct sowing

What is physiological dormancy (PD)?

A condition controlled by factors within the embryo that must change before germination can occur.

What is the cold stratification process for physiological dormancy?

Placing seeds in a moist but well-aerated media and keeping them cold for 1-2 months.

What is double dormancy?

A condition where both physical and other types of dormancy are present, requiring the seed coat to be opened first, and cold stratification second.

What is morphophysiological dormancy?

A type of dormancy that has both morphological and physiological factors.

When is it recommended to sow seeds with morphophysiological dormancy?

In the fall.

What is secondary dormancy?

A condition caused by environmental conditions that leads to a temporary halt in germination.