What does a seed need to germinate?

Under appropriate conditions the seeds can germinate and originate new plants, but they can also remain in a state of lethargy if those conditions do not occur, even more can die if they are adverse.

Among the internal conditions we have to consider:

• Vitality or viability of the seed:That consists of leaving the state of lethargy and germinating.
• Longevity: that is, the time during which the seed can remain dormant without losing its ability to survive.

Taking these two conditions into consideration, the farmer chooses his seeds among the healthiest, in order to obtain vigorous plants with a high percentage of germination.

As a result, tests are usually carried out to determine the percentage of germination of the seeds by placing, for example, 100 seeds in wet sand or sawdust, or also between sheets of blotting paper or wet cloth, for a variable period of time with the species, and then the seeds that germinated are counted, this number indicates the percentage.

Not all seeds germinate after reaching maturity, even when placed in appropriate conditions. This is called seed lethargy, and the causes of this phenomenon reside in the perisperm and in the embryo.

External conditions: in order for the embryo to pass from the state of dormant life to active life, it is necessary to gather certain factors, among which the most important are: water, oxygen, temperature and light.

Water: it is the most important factor, especially if we consider that the seed contains so little quantity. The water acts by restoring the perisperm, so that the embryo can expand and break it, transporting in solution the nutritious elements that the embryo needs in its development: oxygen, sugar, proteins.

Oxygen: breathing is the source of energy to maintain life in the new plant, some seeds are known that can germinate in the absence of oxygen, but none can complete germination without this element.

Temperature: Many seeds do not germinate below 5 ° C, which is what is designated as the minimum temperature. Another large majority does not germinate above 45 ° C, which is the maximum temperature. The temperature at which most seeds germinate is that which is around 25 ° C, and which is called optimum temperature. Of course, each seed has its maximum, its minimum, and its optimum, which must be determined by each species.

Light: Many seeds to germinate, need light, as it happens with many grasses; others are indifferent as is the case of the caraota and the corn and finally, other seeds that do not germinate in the presence of light.