Scarification
Scarification in botany involves weakening, opening, or otherwise altering the coat of a seed to encourage germination. Scarification is often done mechanically, thermally, and chemically. The seeds of many plant species are often impervious to water and gases, thus preventing or delaying germination.
Full Answer
What is meant by scarification of seeds?
Seed Scarification: nicking, breaking, softening, or otherwise weakening of the seed coating meant to speed up germination. You can see the hard, almost walnut-like seed coating on these Nasturtium seeds. For best germination, you can nick the outer coating and soak the seeds overnight before planting.
Why is seed scarification important?
It is important to reduce the hard seed content and improve germination for successful stand establishment of these crops. Seed scarification (a technique to physically damage the seed coat to reduce hard seed while keeping the seed viable) is used to soften hard seeds.
How do you scarify plant seeds?
1:528:10This will work you can either pinch the seed and rub it on the sandpaper a little bit or press itMoreThis will work you can either pinch the seed and rub it on the sandpaper a little bit or press it down and drag it across towards you.
What is an example of scarification?
In chemical scarification, seeds are dipped into strong sulfuric acid, organic solvents such as acetone or alcohol, or even boiling water. In mechanical scarification, they may be shaken with some abrasive material such as sand or be scratched with a knife.
How is scarification done?
Scarification is done either by cutting repeatedly with a scalpel, using a cauterizing tool, or by "strike branding," which is much like cattle branding. After cleaning the area and stenciling on the design, the artist begins cutting or burning the skin until reaching the right depth and width.
Why is scarification done?
Scarification is a form of permanent body modification that involves cutting or burning a pattern or design onto the skin. Traditionally, within indigenous cultures, people may perform scarification for ritualistic purposes, such as rites of passage or to prepare children for adulthood.
Should you scarify seeds?
Nicking seeds before planting helps the seeds absorb water, which signals the plant embryo inside to begin the germination process. Nicking plant seeds and then soaking them in water will jump-start germination and get your garden growing faster. This technique is also known as scarification.
How are seeds naturally scarified?
Seed scarification in nature The seeds lie dormant through winter, where they are subjected to natural forms of scarification. Freezing temperatures cause the outer coating to expand and contract until it is damaged enough for water to get through.
Which chemical is used for scarification?
Scarification can be done mechanically or chemically. Examples of mechanical scarification include filing, stabbing, and cutting. Chemical scarification uses chemical materials such as H2SO4, KNO3, and HCl. These treatments have been shown to break some seeds' dormancy.
How does scarification affect germination?
Scarification is a pretreatment of seeds that aims to break seed dormancy and accelerate the occurrence of uniform seed germination. Scarification is a way to provide a permeable condition of seeds through puncturing, burning, breaking, filing, and scratching with knives, needles, sandpaper, and other tools [1].
Which seeds do you soak before planting?
A short list of seeds that like to soak are peas, beans, pumpkins and other winter squash, chard, beets, sunflower, lupine, fava beans, and cucumbers. Most other medium-to-large vegetable and flower seeds with thick coats benefit from soaking.
What is seed stratification and how does it work?
What is Seed Stratification? Stratification is a process of pre-treating seeds in order to simulate natural conditions that seeds would experience in the soil over-winter. Pre-treating seeds helps the seed "break dormancy" and initiate the germination process.
Do all seeds need scarification?
Large or hard seeds like those of beans, okra, and nasturtium often require scarification for optimal germination. Most plants in the tomato and morning glory families also have impermeable seed coats and will germinate better after scarification.
What is scarification in agriculture?
Scarification in botany involves weakening, opening, or otherwise altering the coat of a seed to encourage germination. Scarification is often done mechanically, thermally, and chemically. The seeds of many plant species are often impervious to water and gases, thus preventing or delaying germination.
How are seeds naturally scarified?
Seed scarification in nature The seeds lie dormant through winter, where they are subjected to natural forms of scarification. Freezing temperatures cause the outer coating to expand and contract until it is damaged enough for water to get through.
How are seeds scarified in nature?
Seed Scarification Any process of breaking, scratching, or mechanically altering the seed coat to make it permeable to water and gases is known as scarification. In nature, this often occurs by fall seeding. Freezing temperatures or microbial activities modify the seed coat during the winter.
How to scarify seeds?
One way to scarify seed is to heat it up, with either moist or dry heat. This breaks down the hard outer shell of the seed and allows water to permeate the seed coating. The trick here is to know how hot the seeds need to be for what period of time. You want to break down the outer shell without damaging the embryo inside.
What is the chemical used to scarify seeds?
Chemical Seed Scarification. Scarifying seeds with chemicals is another method of breaking dormancy that is studied quite a bit. Sulfuric acid is the chemical most often used in studies that have examined this method.
How to break down seed coating?
One of the more popular and easily accessible ways to do this is by rubbing seeds between two sheets of medium-grit sandpaper. Remember that the goal here is to encourage germination by softening, or creating small abrasions in the hard outer shell, but not pulverizing it.
What is the name of the herb that is grown in a seed?
Herbalist and author Richo Cech suggests this method when planting astragalus (Astragalus mongholicus) seeds (Strictly Medicinals, n.d.). You might also know this herb as Astragalus membranaceous or milkvetch, and the seed may be listed as any of these.
Why do seeds need to come out of shell?
Learning a bit about the conditions a seedling needs to come out of its shell will increase germination rates and help boost a garden’s potential.
What is the goal of scarification?
The goal of scarification is to wear down the tough outer shell of the seed, so that water is able to reach the inside. The introduction of water to a seed is the catalyst that restarts metabolic and respiratory functions. Both functions fuel the growth of the embryo, and the emergence of the seedling (Bewley, 1997).
What conditions do seeds need to survive?
Seeds are so adept at surviving these conditions that they come to depend on them, whether those conditions consist of fire, abrasion, or corrosion. Learning a bit about the conditions a seedling needs to come out of its shell will increase germination rates and help boost a garden’s potential.
Why do we use scarified seeds?
Common uses. Because scarified seeds tend to germinate more often and in less time than unaltered seeds, scarification finds use not just in industry but on the small scale. In home gardens, for example, the seeds of plants which are otherwise difficult to grow from seed may be made viable through scarification.
What is the process of scarification?
Scarification in botany involves weakening, opening, or otherwise altering the coat of a seed to encourage germination. Scarification is often done mechanically, thermally, and chemically. The seeds of many plant species are often impervious to water and gases, thus preventing or delaying germination. Any process designed to make the testa (seed coat) more permeable to water and gases (and thus more likely to germinate) is known as scarification.
How high is the germination rate of silky lupine?
The Silky lupine’s highest germination rate was achieved via mechanical scarification at 66.4% , opposed to its 22% germination rate found in the control group. Using thermal and chemical scarification, germination increased to 48.8% and 44% respectively.
What is the most common type of scarification?
The most common type of scarification is mechanical scarification. In mechanical scarification, the testa is physically opened to allow moisture and air in. Seed coats may be filed with a metal file, rubbed with sandpaper, nicked with a knife, cracked gently with a hammer, or weakened or opened in any other way.
How does scarification work?
Scarification, regardless of type, works by speeding up the natural processes which normally make seed coats permeable to water and air.
Do chaparral plants need fire scarification?
An exception to that phenomenon is Western poison oak, whose thick seed coatings provide a time delayed effect for germination, but do not require fire scarification.
Does water affect seed shell membrane?
The imbibition of water through seed shell membrane is affected by water temperature. Species that can withstand hot water will sprout faster under that condition than from cold tap water.
