What conditions break seed dormancy?
As a result, the seed is prevented from germinating until dormancy is broken. In natural systems, physical dormancy is broken by several factors including high temperatures, fluctuating temperatures, fire, freezing/thawing, drying or passage through the digestive tracts of animals.
What three factors are required for a seed to break dormancy and germinate?
All seeds need water, oxygen and the right temperature to germinate. Dormancy is a state of suspended animation in which seeds delay germination until conditions are right for survival and growth.
What causes seeds to break their dormancy and germination?
Scarification breaks dormancy in the same way that freeze/thaw cycles and animal chewing or digestion do. Rainwater, drying, temperature, or light changes may break chemical dormancy in nature and horticulture. Seeds germinate by absorbing water, resuming metabolism, and finally liberating the embryo.
What are two environmental factors that can end a seeds dormancy?
Apart from the basic requirement of water, oxygen, and a suitable temperature, the dormant seed may be sensitive to other environmental factors such as light and/or nitrate which are capable of removing the final layers of dormancy.
What’s the best way to break the dormancy of seeds?
Exposure to heat, cold or light, depending upon the type of seed dormancy. By applying Hydraulic pressure for 5 to 20 minutes in order to weaken the tough seed coats. Seed coats are treated with concentrated sulphuric acid for removing all traces of the mineral acid. Treatment to break dormancy in seeds
What are the natural causes of seed dormancy?
Other natural methods include: Completion of the over-ripening period. Leaching of inhibitors present in the seed coat. Inactivation of inhibitors by the supply of cold, heat, and light. Leaching of the excess and highly concentrated solutes from the seeds. Production of growth hormones which can neutralize the effect of inhibitors.
Why do some plants have dormancy while others do not?
In some species, seeds have dormancy due to hard seed coats and dormant embryos. For instance, some tree legumes seed coats are impervious and at the same time their embryo are also dormant.
What can be done about the dormancy of seed coats?
Seed coats are treated with concentrated sulphuric acid for removing all traces of the mineral acid. There are separate treatments to overcome dormancy, and they are further divided into the following groups: These treatments make a hard seed coat permeable to water or gases either by softening or cracking.