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Got seeds? Just add bleach, acid and sandpaper - Mary Koga
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Got seeds? Just add bleach, acid and sandpaper - Mary Koga

 
So, the apocalypse has happened. The zombies have come and gone, and all plant life on Earth has died somehow. All you have are some basic supplies and some seeds of a few types of essential plants. So, what should you do to make absolutely sure they grow, seeing how rebuilding human civilization absolutely depends on it? Well, you'd probably think the last thing you should do with these crucially important seeds is something like poking holes in them, or grinding them with sandpaper, or throwing them in acid or hot water. But, in fact, all of these are methods that are commonly used to help seeds start growing. A typical seed consists of a plant embryo encased in a hard seed coat. To start growing, it needs to emerge or sprout from inside this shell. This process is called germination. But just as it would be hard for you to get out of a jail cell with no windows and no doors, the embryo might need a little help escaping from its seed prison, and any process that makes this easier by wearing down the seed coat is called scarification. This lets moisture and nutrients get through the seed coat, making the embryo start growing until it breaks through. Now, you might be wondering why it is that plants would need humans to do all these weird things to their seeds in order to grow, and, in fact, they don't. In natural environments, seed coats are worn down by cold temperatures, bacteria, or even animal digestion. Our scarification methods just mimick and accelerate these natural processes to increase the chances of successful germination. One technique we can use is called nicking. To do this, we make a small cut or scratch into the seed coat. Be careful not to cut too deep! You don't want to damage the plant embryo inside. Another way is to file down the seed coat using sandpaper or a nail file. Once again, you don't want to file too much, just enough to wear down some of the seed coat. After applying either of these methods, you'll want to spray the seeds with bleach to prevent mold. Seeds can also be soaked in water to soften the coat. One way to do this is to place the seeds in a nylon bag, then place the bag into hot water. Turn off the heat immediately and allow the water to cool to room temperature before removing the seeds. It's important not to heat the seed for too long as this will kill the embryo. Again, you'll want to spray them with bleach afterwards. Finally, you can try immersing the seeds in a sulfuric acid solution. Make sure you're wearing protective goggles and gloves any time you work with such a dangerous substance. Place the seeds into a wire mesh pouch and immerse the pouch in the solution for ten minutes. Then take out the pouch and rinse it with clean water. Take out the seeds and, as before, spray them with bleach so they don't get moldy. If you try all of these methods, you will see that some of them are more effective than others, and some work best for different types of plants that have harder or thicker coats. So, knowing what seed scarification techniques work best will be useful if you ever need to survive a cataclysm, start a farm, or just want to plant in your own garden.

Mary Koga, Provincia, Studio, seed, shell, scarification, germination, seed, scarification, planting, seeds, TED TED-Ed TED Ed, TEDEducation

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