Seed dormancy is a state of seed that make unable to seed germination, even if sufficient condition of germination is present.
Seed dormancy may be in different cotagories.
On the basis of dormancy based on inside factor and outside factor is endogenious dormancy and exogenious dormancy.
When seed become dormant for outaide environment of seed is exogenious dormancy. When seed dormant based internal factors of seed called endogenious seed dormancy.
The different factor that plays a vital role in seed to become dormant is as bellow,
The immaturity of seed
Temperature of environment
Water Insufficiency
The existence of chemical prohibitors
Seed coat structure
Light
There should have three kinds of dormant seed and seed dormancy.
Innate dormancy
Innate dormancy of seed that seed become dormant even existing the favorable environment to germinate. If the fruit is immatured seed could be dormant. It is the primary dormancy.
Enforced dormancy： If seed is matured to germinate but show dormancy for external environmental forces is called enforced dormancy.
Induced dormancy： When any matured seed places under any unfavorable environment for a short period of time but when it found anyy favorable environment it may shows dormancy. That is induced dormancy.
A dormant seed may be capable to germinate if sufficient level of environment is provided. Even some mechanical and chemical expousere may break down dormancy. Breakdown of seed dormancy is beneficial for cultivators because it can prevent loss.
A one thing should taken into consideration that immature seed in plant fruit will breakdown its dormancy when it matured in plant.
How breakdown of seed dormancy will occur depends on the causes of dormant seed.
If seed dormancy is caused for thick seed coated then dormancy may be break down by thining of coats by mechanical or chemical exposure.
If temperature impacts on seed dormancy then the changing of temperature may breakdown the dormancy.
If embryo of seed be sufficient level of matured its dormancy is easier to breakdown.
Water infiltration is very important for seed to germinate. Hence, wet environment is very essential for germination.
Wetting of seed allows the seed to expand in size. It also allows infiltration of water.
