Seeds and their germination process.

Dear readers, in agricultural production, plant propagation is of utmost importance to obtain items of food interest, for this, there are asexual propagation materials (vegetative parts of the plant) and sexual (seeds), the seeds are the main reproductive organ of the vast majority of plants and whose function is to ensure the ecological succession of vegetative species, with them, they can be renewed and distributed geographically in agricultural and natural ecosystems. It can be said from the agricultural approach, that the seed is the starting point for production, so it is necessary to have the necessary conditions to produce vigorous seedlings to ensure adequate production of the items you want to get.

Seeds have the capacity to remain dormant for a certain period of time, until they reach the ideal conditions to germinate (generate a seedling). Some authors, such as Parker (2000), mention that if a seed cannot germinate in a determined period of time, the embryo located inside it will die; the dormancy time will depend on the species. In this sense, for a seed to have high viability and for the embryo inside to begin to grow, it is necessary the presence of certain external elements that will be mentioned below:

- Water: when sowing with sexual seeds, it must be guaranteed that the soil has adequate humidity levels, so that the imbibition process takes place, that is to say that the seed absorbs the water, once the water penetrates the seed, the nutritional elements that are in it will dissolve, which will guarantee the stability of the seedling that will emerge from it, on the other hand, the water has the function of softening the integument or cuticle of the seed, which will facilitate the exit of the radicle (first root of the plant).

- Air: in the germination process, the need for oxygen increases so that the plant can emerge, therefore, the environment where it develops must be well aerated. For this reason, before carrying out the planting process, it is necessary to verify that the soil is not compacted, and it is there where tillage plays a fundamental factor, to loosen the soil and guarantee aeration and therefore the presence of oxygen, in order to have a high germination percentage.

- Temperature: seeds can be affected by both excessive cold and heat, therefore, the seeds of some species have maximum and minimum temperatures to germinate, such as tomato has a minimum temperature for germination of 10 °C and a maximum of 35 °C, therefore, we see it germinate well in temperate and tropical climates. In other words, when selecting a crop we must verify that temperatures do not considerably affect germination.

As could be seen, the external factors mentioned above together with internal factors such as the maturity of the seed are fundamental in the propagation of plants, in the germination process begins with the emergence of the radicle, the presence of the seminal leaves (cotyledons) and the first true leaves. Once the seed has germinated, the emergence of the seedling is evident, which consists of the breaking of the soil surface to give way to the seedling.

Dear readers, it can be said that germination is the process that begins the growth of seedlings and knowing the factors mentioned above allows us to make the right decisions at the time of planting. There are some seeds that have a thick tegument, for that you can perform some procedures known as scarification, which consists in softening or reducing the thick tegument so that it can be easily hydrated.