DEFINITION
A seed is an embryonic plant enclosed in a protective outer covering. It is a reproductive structure which disperses, and can survive for some time.
Many seeds are edible and the majority of human calories comes from seeds, especially from cereals, legumes and nuts.
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| Brown flax seeds |
Many structures commonly referred to as "seeds" are actually dry fruits. For instance, sunflower seeds are sometimes sold commercially while still enclosed within the hard wall of the fruit, which must be split open to reach the seed.
GERMINATION AND DISPERSION
Seeds develop from a fertilized ovule and consist of an embryo and a food store, surrounded and protected by an outer seat coat, called the testa. The food store is contained either in a specialized nutritive tissue, the endosperm, or in the cotyledons of the embryo itself.
In angiosperms (flowering plants) the seed is enclosed within a fruit, whereas in gymnosperms (a group of seed plants which includes conifers, cycads and Gnetales) it is usually naked and unprotected, once shed from the female cone.
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| Wilikpedia |
Following germination the seed develops into new plants but there may be a delay in germination to ensure growth occurs under favorable conditions.
When the seed is ready to develop, it needs water, air and warmth but not sunlight to become a seedling.
Seeds may be dispersed from the parent plant in a number of different ways. Agents of dispersal include animals, as with barrs and fleshly edible fruits, or wind, where the seed or fruit may be winged or plumed. Dandelion seeds are contained within achenes, which can be carried long distances by the wind.
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| Pixebay |
Water can disperse seeds of fruits that float, and various mechanical devices may eject seeds from the fruit, as in some pods are legumes.
SIZE
Seeds are very diverse in size. The dust-like orchid seeds are the smallest, with about one million seeds per gram; they are often embryonic seeds with immature embryos and no significant energy reserves.
The largest seed is produced by the Coco de mer, or "double coconut palm", Lodoicea maldivica. The entire fruit may weigh up to 23 kilograms (50 pounds) and usually contains a single seed.
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| Female coco de mer growth Wikipedia |
Almost 2,000 carrot seeds will fit into, a teaspoon.
HISTORY
The seed drill is a machine for sowing cereals and other seeds, developed by Jethro Tull (1674 – February 21, 1741), in England in 1701. The seeds are stored in a hopper and delivered by tubes into furrows made in the ground by a set of blades called coulters attached in front. A harrow is drawn behind the drill to cover up the seeds.
Before Tull's invention, people sowed seeds by scattering them by hand. Tull's machine could plant several rows of seeds at regular intervals, which meant that less seed was wasted. Tull used his first seed-drill on his own farm without telling anybody else for thirty years. His invention was the first step in the use of machines in British agriculture.
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| 1902 model 12-run seed drill Monitor Manufacturing Company. By trekphiler |
During the Siege of Leningrad in World War II, nine Soviet scientists died of starvation while protecting the world's largest seed bank, refusing to eat what they saw as their country's future.
2,000-year-old Judean date palm seeds were discovered in 1963 inside an ancient jar in Israel. The seeds were planted in 2005 and a tree that had been extinct for over 1800 years sprouted.
The upper survival time limit of properly stored seeds remains unknown. Some scientists believe that seeds can last for thousands of years, if they are stored in the right conditions. However, there is no guarantee that any particular seed will survive for that long.
The conditions that are best for storing seeds are cool, dry, and dark. Seeds that are stored in these conditions are less likely to deteriorate and lose their viability. However, even seeds that are stored in these conditions can eventually degrade and become non-viable.
The ceremonial "first stone" of the Svalbard Global Seed Vault, a facility established to preserve a wide variety of plant seeds from locations worldwide in an underground cavern in Spitsbergen, Norway, was laid on June 19, 2006. There arctic vault stores over 860,000 different varieties of food crop seeds as an insurance policy for the world’s food supply.
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| Seed storage containers on metal shelving inside the vault. By NordGen/Dag Terje Filip Endresen |
FUN SEED FACTS
The conditions that are best for storing seeds are cool, dry, and dark. Seeds that are stored in these conditions are less likely to deteriorate and lose their viability. However, even seeds that are stored in these conditions can eventually degrade and become non-viable.
SK AGRO is the Top Seed Grader Machine Manufacturers.
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