Cultivation Of Maize

Maize (also known as wheat from India to Canada) is a tropical herbaceous annual plant of the family Poaceae, widely grown as cereal grains rich in starch, but also as a fodder plant. The term also refers to the grain of corn itself, the size of a pea.

This species, native to Central America, South America and North America, was the staple diet of American Indians before the arrival in America of Christopher Columbus. The plant was deified in the ancient civilizations of Central and South America and was known among the tribes of North America as one of three sisters. Introduced in Europe in the sixteenth century, it is now cultivated worldwide and has become the first World cereal to rice and wheat. With the advent of hybrid seeds in the first half of the twentieth century, and transgenic seeds recently, corn is the symbol of intensive agriculture.

Its common name is the most common corn. This term comes from the Spanish maíz, itself borrowed the language of the Taíno of Haiti who grew. Many other names have been applied to this grain, particularly wheat Indian wheat and wheat Turkey Barbary. Obsolete for the most part, these names reflect the confusion that has long prevailed in Europe about the origin of the plant.

* Scientific name: Zea mays of the family Poaceae, grasses.
* Synonyms: sweet corn: sweet corn, wheat Barbary, Guinea wheat, wheat in Turkey, Indian wheat, popcorn: fulminant corn, pearl maize, popcorn ...
* Sweet corn: English: sugar corn, sugar maize, sweet corn, German: Zuckermais, Süßmais, Korn Welsch, Spanish maiz dulce, Italian: grano turco, but sweet, Dutch: corn, turksche tarwe
* Popcorn: English: pop corn, German: Puffmais, Perlmais, Spanish Reventón maiz, maiz Palomero, Italian, but ibrido, Dutch: pofmais

Description

The corn is an annual herb, variable size (from 40 cm to 5 m, usually between one and three meters to the commonly cultivated varieties)

The single stem and large diameter is full, woody and trained several internodes of about twenty centimeters separated by as many nodes. At each node is a leaf inserted alternately on one side and the other of the stem. The leaves are typical of grasses, but large (up to 10 cm wide and one meter long), have a sheath through which the stem and leaf blade elongated ribbon veins parallel. At the base of the blade is the ligule has a few millimeters high. Unlike other grasses, corn foot does not install, however it is sometimes secondary stems, of limited size, at the base of the main stem.

The root system consists of a very large number of adventitious roots that arise on the nodes at the base of the stem, forming successive crowns, both buried on the nodes on the first air nodes in an area where the internodes are very short . These roots form a system specification that can reach a depth greater than one meter.

Flowers, another characteristic that distinguishes the maize and other grasses, and are grouped into unisexual male and female inflorescences composed of spikelets of two flowers.

The female flowers are clustered in spikes inserted into the leaf axils median (the largest). The axis of the ear, called the raid, is 10 to 20 rows of female flowers. A single flower per spikelet is fertile. It is surrounded by modified leaves, the husk, dry at maturity. At the top end, leaving the husk exceed stigma filiform or bristles. An ear can hold about 500 grains at maturity, sometimes miles. One foot gives rise to three or four ears, but only one reaches full development.

The male flowers are clustered in a terminal panicle that appears after the last sheet. The panicle is composed of spikelets each comprising two flowers three stamens.

The grain of corn is a caryopsis, consisting of three parts of different origins:

* Embryo, commonly called "germ", located at the base of the grain which includes the embryo itself or gemmule and the scutellum, ie the cotyledon, as the reserve in which the plant draws its initial energy, the embryo comes from the egg formed following the merger of the nucleus of a spermatozoon and the oosphère;
* Albumen, tissue reserves, mainly composed of starch grains, except the peripheral layer beneath the pericarp contains aleurone grains rich in proteins, this fabric is merging the nucleus of a sperm and two nuclei of the central cell (that is a fabric 3n chromosomes);
* The outer, thin, fibrous membrane translucent, issue of the pericarp of the ovary (so in reality a part of the fruit and not the seed).

The starch of the endosperm occurs in two forms: amylose, linear polymer of glucose, and amylopectin, forming a polymer molecule branched. According to the method of assembly of these molecules causes the formation of starch chalky, crumbly structure, located somewhere near its center, or the horny starch, or vitreous, to dense and compact structure, located in the periphery and contributes to maintain the external shape of the grain. The varying proportions of these two forms of starch can distinguish different races. It's the horny starch that gives color to the grain of corn, usually yellow, but white, red, black, while the starch is still chalky white.