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Hello readers of all, this time ahli artikel will explaining an article about seeds. Please read the discussion below.
Importance of good seeds
Reasonably good seed is a prime essential to successful crop production, whereas poor seed is a serious farm hazard. The variety and the approximate germination and purity of seed should be known before it is planted. Introduction of weeds in the seed often increase the labor for production of the crop, reduces crop yields, and contaminates the current product as well as the seed and soil in future seasons.
Seed Germination
External Condition for Germination
The most important external condition necessary for germination of matured seeds are ample supplies of moisture and oxygen, a suitable temperature, and, for some seeds, certain light conditions. A deficiency in any factor may prevent germination.
Reasonably good seed is a prime essential to successful crop production, whereas poor seed is a serious farm hazard. The variety and the approximate germination and purity of seed should be known before it is planted. Introduction of weeds in the seed often increase the labor for production of the crop, reduces crop yields, and contaminates the current product as well as the seed and soil in future seasons.
Seed Germination
External Condition for Germination
The most important external condition necessary for germination of matured seeds are ample supplies of moisture and oxygen, a suitable temperature, and, for some seeds, certain light conditions. A deficiency in any factor may prevent germination.
Good seed show a germination of 90 to 100 per cent in the laboratory. Some sound cop seeds, particularly small grains, show a seedling emergence of as high as 90 per cent of the seed when sown under good field conditions. Even corn, which is a rather sensitive seed, often produces stands of 90 per cent or more in the field. Sorghum and cotton give a lower percentage of emergence because they are more susceptible to attack from seed-rotting fungi. In sorghum, a field emergence of 70 per cent is exceptional, while 50 per cent emergence is all that is normally expected from seed with a 95 per cent laboratory germination, even in a good seedbed. However, when the seed germinates only 60 to 70 per cent in the laboratory, many of the sprouts will be so weakened that a field emergence of 20 to 25 per cent is all that can reasonably be expected. In a poor seedbed, the emergence may be much less. Seeds that germinate slowly may produce weak seedlings. However, the strong seeds in a low-germinating sample may give good yields, provided enough seed is planted.
Process of Germination
When placed under the proper condition, seeds capable of immediate germination gradually absorb water, until, after approximately 3 days, their moisture content may be 60 to 100 per cent of the dry weight. Meanwhile the seed coats have become softened and the seeds swollen. Soluble nutrients, particularly sugars, go into solution. Starch is hydrolyzed into maltose by the enzyme diastase, which is found in greatest quantities in the epithelial layer of the scutellum. The maltose is hydrolyzed into glucose by the enzyme maltase. The soluble glucose is transported to the growing sprout chiefly by diffusion from cell to cell, and there is synthesized into cellulose, nonreducing sugars, and starch. Proteins broken down by proteolytic enzymes into amides-e.g., asparagin- and into amino acids, the build proteins in the seedling. Fats, which occur chiefly in the cotyledons of certain oil-bearing seeds and in the embryos of cereal seeds, are split by enzymes called lipases into fatty acids and glycerol. These in turn undergo chemical changes to form sugars, which are used to build up the carbohydrates and fats in the seedling. Energy for the chemical and biological processes of germination and growth is supplied by respiration, or biological oxidation of carbon and hydrogen into carbon dioxide and water. During germination respiration proceeds rapidly at a rate hundreds of times that in dry seeds.
Until here first explanation of the article about SEEDS. Please read, hopefully we can add to the knowledge of the reader
HAPPY LEARNING
SOURCE:
Book Principles of Field Crop Production | John H. Martin - Warren H. Leonard | COLLIER Macmillan (1967)
Book Principles of Field Crop Production | John H. Martin - Warren H. Leonard | COLLIER Macmillan (1967)
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