The corn is native from America, where it was the basic food of the cultures many American centuries before the Europeans arrived to the New World. The origin of this plant continues being a mystery. There are conclusive tests, contributed by the archaeological discoveries and paleobotánicas, that in the valley of Tehuacán, to the south of Mexico corn was already cultivatedapproximately 4.600 years ago. The wild primitive corn didn't differ much of the modern plant in its botanical fundamental characteristics. In Spain it began to be cultivated in 1604, introduced in Asturias by the governor from Florida. During the XVIII century, the cultivation spread in a gradual way for the rest of EuropaEl geographical center of origin and dispersion is located in the valleyof Tehuacán, State of Puebla, in the Central denominated Table of Mexico to 2.500 m on the sea level. In this place the North American anthropologist Richard Stockton MacNeish found archaeological remains of plants of corn that, he/she is considered, they date of the 7.000 to. C. Keeping in mind that there the center of the Aztec civilization was it is logical to conclude that the corn constitutedfor the primitive inhabitants an important source of feeding. Even, they can be observed in the galleries of the pyramids (that they are still conserved) paintings, engravings and sculptures that represent to the corn. The Meso-American big civilizations would not have arisen without the agriculture, and without a system of mensuration of the time that organized their daily activities and ritualsof the Meso-American towns. The calendar determined the moments in that it was cultivated, you traded or the war was made and he/she also said the destination
THE PLANT OF THE CORN.
Zea mays is a plant monoica; its masculine and feminine inflorescences are in the same plant. Although the plant is yearly, its quick growth allows him/her to reach until 2,5 m of height, with an erect, rigidshaft and solid; some wild varieties 7 m of altura.4 reaches
The shaft is compound in turn for three layers: an external epidermis, raincoat and transparent, a wall for where the nutritious substances and a marrow of spongy and white fabric circulate where it stores nutritious reservations, especially sugars.
The leaves take a lengthened form intimately rolled to the shaft, of which the spikes orears are born. Each ear consists on a trunk or olote that it is covered for lines of grains, the eatable part of the plant whose number can vary between eight and thirty.
The corn is a plant of long nights and it flourishes with a certain number of days grades > 10 °C (50 °F) in the atmosphere to the one which you adaptó.5 That magnitude of the influence of the long nights makes that thenumber of days that you/they should happen before it flourishes prescripto is genetically and regulated by the system-fitocromo.6 The fotoperiodicidad can be eccentric in tropical cultivares, while the long (short nights) days characteristic of high latitudes they allow to the plants to grow so much in height that you/they don't have enough time to produce seeds before being annihilated for icy. Thoseattributes, however, they can be very useful they stop to use tropical corn in biofueles.7
The corn is a plant monoica, absolutely able of reproducing by itself, when possessing masculine and feminine flowers in the same foot [it mentions required]. Apparently the thick recubrimiento of brácteas of their ear, the form in that the grains are willing and fellows are compactly, they would preventthat the plant can make germinate their grains. Its symbiosis with the human species would pretend to be total, to such a point that some investigators call it a cultural" "device, although these they are magic concepts, far from the reality, when a spike falls to the floor, the brácteas is consumed by mushrooms, and they are not it their cariopses that are able to germinate, being generated a...