Dormancy in seeds is a common issue for farmers majorly in soil seed banks. Dormancy in seeds is simply the result of improper environmental conditions. Owing to the adverse environment, seeds stop germination. Even though you might curse dormancy, trust me, many plants would have extinct long ago without seed dormancy. Dormancy helps seeds to adapt to changing environments and survive extinction.
We will have more insights on seed dormancy throughout the blog. If you are new to the idea, you might want to go through Dormancy in Plants.
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What is Dormancy in Seeds?
Seeds are a crucial part of any plant. Seeds help plants to sustain themselves. But a seed might always not ensure a birth. Meanwhile, the germination of seeds can halt anytime, resulting in dormant seeds.
Dormant seeds fail to produce plants, hence someone like you looking forward to healthy and happy plants might get heartbroken.
Why does Dormancy in Seeds happen?
Dormancy occurs as triggered by adverse situations where the baby plant might not survive in the soil seed bank. Improper soil conditions, lack of sufficient water, nutrients, oxygen, temperature and other required factors can easily trigger dormancy in seeds.
Plants often use dormancy so that seeds can withstand adverse conditions and not all germinate at once saving them from perishing in bad weather. This has helped plants to adapt to weather and other changes and saved them from extinction.
What are the Types of Dormancy in Seeds?
You can divide the types of dormancy into five categories by the reasons behind dormancy;
- Physiological dormancy or secondary dormancy is the major type of dormancy in mature seeds where seeds shut down the germination process owing to the harsh environment. This happens internally as an influence of external factors. Most of the seeds fail to germinate owing to such dormancy.
- Morphological dormancy is the result of immature seeds. As the seeds are not mature enough, they never make it to the next stage till the germination of seeds.
- Morphophysiological dormancy is the result of both Psychological and Morphological dormancy, where the seed is immature or simply incomplete and faces psychological issues while germination.
- Physical dormancy or primary dormancy is caused by water-impermeable layers of palisade cells in the mature seed or fruit coat that control water movement. This can easily be avoided by keeping watering in control.
- Combinational dormancy is simple the joint reason for physiological and physical dormancy or primary dormancy and secondary dormancy in any mature seed.
How to Treat Dormant Seed?
There are some simple ways to break dormancy in seeds. You can use one from the below to ensure germination in your seeds,
- Seed Scarification: Seed scarification can be your best option to fight dormancy in seeds. Seed scarification helps you to break the seed coat and help the seed bloom.
Scarification refers to any process of breaking, scratching, or mechanically altering the seed coat to make it permeable to water and gases. In nature, this is effectively achieved through fall seeding. During the winter, freezing temperatures or microbial activity alter the seed coat. Scarification can also happen when seeds pass through the digestive systems of different animals.
Scarification can also be forced rather than allowing nature to change the seed coats. Scarifying seeds is done commercially by soaking them in concentrated sulfuric acid. Sulfuric acid is poured over the seeds in a glass container. Depending on the species, the seeds are gently stirred and allowed to soak for 10 minutes to several hours. Various reference books provide appropriate treatment concentrations and durations. The seeds are removed, washed, and soon after the seed coat has been modified (thinned). Sulfuric acid, on the other hand, can be extremely dangerous for inexperienced users and should be used with extreme caution! Vinegar is a less dangerous (but less effective) treatment that can be used on species that do not have an extremely hard seed coat; the technique is the same as with sulfuric acid.
- Seed Stratification: Your second method to fight seed dormancy can be seed stratification.
Morphophysiological dormancy, which is regulated by the inner seed tissues, is the second type of imposed dormancy found in seeds. When environmental conditions are not favourable for seedling survival, this dormancy prevents many species’ seeds from germinating. There are various degrees or types of internal dormancy. Internal dormancy that is “shallow” simply disappears with dry storage. This type of dormancy can be found in many vegetable seeds. There are no special treatments required to break this type of dormancy.
Another type of internal dormancy, on the other hand, necessitates specialized treatment. Seeds with this type of dormancy will not germinate until they are subjected to a specific period of moist-prechilling and/or moist warming. Cold stratification (moist-prechilling) entails placing seeds in a closed container with an equal volume of a moist medium (such as sand or peat) and storing them in a refrigerator (around 40°F).
Seeds of some species exhibit what is known as double dormancy. This is a combination of seed coat and internal dormancy. To achieve germination with seeds having double dormancy, the seeds must first be scarified and then stratified for the appropriate length of time. If the treatments are administered in reverse order, the seeds will not germinate. After these treatments, sow the seeds under the proper environmental conditions for germination.
These two are two great methods for you to carry out in your home. The rest will need to get you a laboratory and some extra degrees in biology.