Thermal scarification, as the name implies, uses heat to weaken the shell. Usually, this is done by plunging the seeds into boiling water and then leaving them to cool and soak for a day or two.
Seed scarification methods have been developed and modified over time to make these more practical and effective. Important methods of seed scarification include heat, freeze-thaw, mechanical and acid scarification.
Heat, freeze-thaw, mechanical and acid scarification are among the most popular methods.
Types of Scarification
Mechanical involves physically opening the seed coating to allow air and water to enter. Chemical involves the use of chemicals to weaken the seed coating and encourage germination. Sulfuric acid is a commonly used chemical for this method.
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.
Large, thick seeds such as morning glory, moonflower, nasturtiums, and purple hyacinth bean are the most likely candidates for scarifying. Although edible beans are large seeds, they will not need scarification.
Thermal scarification, as the name implies, uses heat to weaken the shell. Usually, this is done by plunging the seeds into boiling water and then leaving them to cool and soak for a day or two.
1. Vulnerability: Scarified seeds can be more vulnerable to damage from environmental factors, such as drought or extreme temperatures. 2. Reduced seed longevity: Scarification can reduce the longevity of seeds, as they may not be able to survive as long in the soil before germinating.
Stratification uses temperature to break dormancy, while scarification uses mechanical, chemical, or thermal means to break down a hard seed coat that is impervious to water. Stratification is the process in which a seed is exposed to moist, cold, or warm conditions in order to break dormancy.
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.
The main point of African scarification is to beautify, although scars of a certain type, size and position on the body often indicate group identity or stages in a person's life. Among the Dinka of Sudan facial scarification, usually around the temple area, is used for clan identification.
Natural scarification
In nature, scarification occurs when animals chew hard-coated seeds (mechanical). Passing through an animal's digestive system also degrades a seed's natural protection (very chemical). Some plants need smoke or fire (thermal scarification) before their seeds will germinate.
Seed coat (external dormancy) results from a seed's hard seed coat that is impervious to water and gases. The seed will not germinate until the seed coat is altered physically. Any process of breaking, scratching, or mechanically altering the seed coat to make it permeable to water and gases is known as scarification.
Which Seeds Need Cold Stratification? The seeds of most annual garden flowers and vegetables require no stratification. However, many trees, shrubs, perennials, and wildflowers will only germinate after their seeds are stratified.
He says scarification often hurts less than a tattoo; in fact, all forms of scarification occur on the same level of the skin as tattoos: on the dermis, far above fatty tissues and muscle matter. The practice is illegal in some countries such as the United Kingdom and several U.S. states.
The act of scarification itself is painful regardless of how it is done. One common method is to cut the skin with a sharp object in whatever pattern is desired.
Offences and penalties
Extreme forms of body modification do cause actual harm and generally leave permanent marks and can result in disfigurement. They can therefore be considered as assaults to the body and so are potentially subject to the legislation concerning assault.
Soaking Seeds Prior To Stratification
Some tips suggest soaking or “pre-soaking” seeds like delphinium or sweet peas in water up to 24 hours prior to cold stratification to help soften the seed coat. This is a type of scarification. Some gardeners do this by placing the seeds directly in a container of water.
A thermal method of analysis is a technique in which measure a physical property of a material as we subject it to a change in temperature. In this chapter we consider three examples of thermal methods: thermogravimetry, differential thermal analysis, and differential scanning calorimetry.
The operation encourages healthy growth and maintains the appearance of greens and tees throughout a busy playing season. The process also improves surface penetration by water and enhances airflow around the plant which minimises the potential for disease.
Some seeds like Allium 'Purple Sensation' and Eryngium giganteum need a long period of cold-moist stratification with alternating temperatures. These are the most difficult seeds to germinate.
By soaking the seed, it enables the new growth from the inside to push through the hard shell and grow. The seeds that could benefit from a good soaking include: corn, pumpkin, beans, chard, beets, and peas. The seeds you shouldn't soak include: carrots, lettuce, radish, celery, turnips, and spinach.
Throw your seeds into a small bowl or cup filled with warm water (just enough to cover the seeds). For thick-skinned seeds like peas, aim for 8 to 10 hours (or overnight, assuming you soak them right before bed and sow them first thing in the morning). For thin-skinned seeds like snap beans, soak for 2 to 4 hours.