Corn or Maize (Zea mays)

Corn or Zea mays or commonly referred to Maize is one of the most important sources of carbohydrates, especially in the western hemisphere. Known, maize has become a staple food of the people of Mexico and Latin America since prehistoric times. From Central America, the plant with the same name of the fruit is then grown to almost all tropical and sub-tropical regions around the world. Currently maize, become an important agricultural business from local, regional to multinational size of scope.

Characteristics of the tree:

Corn is a tropical grass plants is very adaptive to climate change and have a life span of 70-210 days. Corn can grow to a height of 3 meters. Unlike other grain crops, maize is a plant that flowers only males and females separately.

Maximum temperature of the corn crop and the start of the growth phase of development is 18-32 degrees Celsius. Beyond that maize can not be grown or even death. Corn can produce good yields on rainfall 300 mm per month. If less than 300 mm per month will result in damage to the maize crop, however, the factors of soil moisture also resulted in reduced yields.

Root: From an anatomical point of view, the roots of corn plants consisting of the epidermis, ground tissue, and endodermis that surrounding the vascular roots system, vascular system composed of xylem and phloem. The epidermis is composed of cells of elliptic and confrontation with two layers of hypodermis. Being morphologically maize root system consists of seminal roots, coronal, and aerial roots. 

The amount of the main outermost roots is between 20 - 30 pieces. Lateral roots that grow from the main root can reach hundreds with 2.5 to 25 cm long. Botanically maize plants including monocot, the main roots emerge and grow entered into the soil since the seed planted. Root growth slowed when the stems begin to arise out of land and then stop when the corn plant has 3 leaves.

Root growths then continued by growth of adventitious roots that develop in the first segment of maize crop. Adventitious roots are not growing from the radicle, then widened and thickened; the root is then played an important role as an enforcer of plants and absorbing nutrients. Adventitious roots were also found growing in the segment to two and three to the trunk, but its main function is not known with certainty.

Trunk: The trunk-shaped segments. In an old maize plant, the distance between sections will be lower. Stem segments can reach the number of 10-40, corn trunk generally unbranched, and trunk has two functions: as a place where the leaves grow and nutrient exchange. Nutrients carried by vessels called xylem and phloem. Phloem moving in either direction from top to bottom and from bottom to top, phloem is sucrose carrier to all parts of the plant in liquid form. Maize stem color is green, green to yellowish.

Leaf: Anatomy of the leaves of maize plants are relatively similar in characters to the grass that living in mild climate areas (mesophytic grass). Outermost epidermal tissue called the cuticle so that has to be rough. Epidermal tissue always outside, crystalline silica found in some types of leaves that come from different varieties. Crystalline silica is adjacent to the epidermal tissue, which serves as a binder. In the monocot plants such as maize, the leaves do not have the palisade tissue. Each vascular system surrounded by parenchyma tissue that hard but thin. Vascular system surrounded by bundle sheath. Corn is a C4 plant types, C4 plants have a large chloroplast cells and scattered rigidly. Chloroplasts located in the mesophyll leaf, which is located in the center of the leaf tissue.

Leaves are formed from the midrib and leaf (leaf blade and sheath). Leaves emerge from the stem segments, appears parallel to the leaf midrib stems. Leaf midrib brown colored covering almost all the corn stalks. In the early phase of growth, stem and leaves cannot be clearly distinguished. This is because the growing point is still below ground. New leaf can be distinguished by the stem when the leaves first 5 in the growth phase, emerge from the ground. New leaves will appear at the growing point. Growing point maize leaves on stem segments. Maize leaf numbering about 20 strands depending on the variety. In line with the growth of maize, stem diameter increases. Leaf color is green to yellowish green.

Flower, fruits, and seeds:

Flowers: Maize is monoecious plant in which every individual plant has male and female flowers. Male flowers lie at the growing point maize plants. When stalled growth phase, intact form of the female flowers will be obvious. Female flowers located in the center of the plant. Pollination occurs in the cornhusk, which will then develop into maize.

Male flowers found in flower panicles at the end of the plant, while the female flowers are found on maize cobs. Stigma stalk is frayed at the ends of hair that always cob wrapped in cornhusk whose numbers 6-14 strands. In the female flowers, there are a number of splitting hair ends and is quite a lot.

Male flowers have a central spike and a few lateral branches. Each spike has many flowers. The flower is called spikelet. Spikelet carrying pollen. Pollen began flying for 2 days before the female flowers are ready to accept. Escape of pollen from the male flowers will continue for 8 days in which the female flower is ready to receive it.

Female flowers appear on the axis of the leaf area (leaf axis). Not all leaf axis may issue female flowers, only 1 or 2 axis leaves may be the growth of female flower.

On maize plants, female flowers appear on the center of the trunk, female flowers similar to male flowers in the form of hair. Pollen from male flowers tied by a silk or a major part female flower shaped like hair. Pollen then fertilizes the pistil.

Fruit and seeds: Every single tree produces one or two corncobs, depending on variety. Corncobs covered by leaves cornhusk. Cornhusk leaf green when young, turn into yellowish white when the fruit has old, and dry. Corn cobs are located on the top of the first established and generally larger than those at the bottom. Each ear consists of 10-16 seed line whose number is always even.

The combination of cob, seeds and skin cover is commonly known as the fruit of corn. Corn cob length between 8-20 cm, depending on the varieties and cultivation techniques.

Corn seed is a type of cereal, the average weight of between 250-300 mg. Corn kernels are classified as caryopsis, because corn seeds have a perfect embryo structure, as well as the nutrients needed by the new individual candidates for future growth and progress. Endosperm is the largest part of the seeds, consisting of hard and soft endosperm. In addition to the endosperm, there is still a pericarp, and embryo. 

Endosperm starch composed of anhydroglucose compounds, most of which consists of two molecules, namely amylase and amyl pectin, and a small portion of material between.

However, in some types there are variations in the proportion of corn amylase and amyl pectin content. Corn grain endosperm protein consists of several factions, which are classified based on their solubility into albumin (soluble in water), globulin (dissolved in saline), or prolamine zein (soluble in high concentrations of alcohol), and gluten (soluble in alkali). In most of the corn, the proportion of each protein fraction was albumin 3%, 3% globulin, prolamine 60%, and 34% gluten.

Nutrient content:

Corn kernels are rich in carbohydrates. Most are on endosperm. Carbohydrate content can reach 80% of all dry seeds.

Carbohydrates in the form of starch are generally a mixture of amylase and amyl pectin. At glutinous corn, most or all of the starch is amyl pectin. This difference has little impact on the nutritional content, but rather as a means in the processing of foodstuffs. Sweet corn contains lower amyl pectin, but has more sucrose.

Corn nutrient content per 100 grams:

• Calories: 355 Calories
• Protein: 9.2 g
• Fat: 3.9 g
• Carbohydrates: 73.7 g
• Calcium: 10 mg
• Phosphorus: 256 mg
• Ferrum: 2.4 mg
• Vitamin A: 510 SI
• Vitamin B1: 0.38 mg
• Water: 12 g

Business and production:

Corn is not only used as food for humans, feed corn is also a good material for livestock, especially poultry. Corn is now an important agricultural commodities in the world, and is cultivated in many parts of the world, be it in a no tropical to tropical. Plant breeding continues to produce the best quality. In developed countries, the agricultural crops of corn have been held in a modern and large-scale.

The United States, China and Brazil are the world's third-largest producer of corn in the world where overall production has reached more than 700 million tons. Of course, the market demand will continue to increase along with the increasing need for food for humans and livestock.

Corn (Maize) as a source of carbohydrate can be grown in all climates, apparently still exciting to be produced as part of the farm business.

Scientific Classification:

• Kingdom: Plantae (Plants)
• Sub kingdom: Tracheobionta (Vascular Plants)
• Super Division: Spermatophyta (Produces seeds)
• Division: Magnoliophyta (flowering plants)
• Class: Liliopsida (dashed one monocots)
• Sub Class: Commelinidae
• Order: Poales
• Family: Poaceae (grasses tribe)
• Genus: Zea
• Species: Zea mays L.

Sub species:

• Flour corn — Zea mays var. amylacea
• Popcorn — Zea mays var. everta
• Dent corn  — Zea mays var. indentata
• Flint corn — Zea mays var. indurata
• Sweet corn — Zea mays var. saccharata and Zea mays var. rugosa
• Waxy corn — Zea mays var. ceratina
• Amylomaize — Zea mays
• Pod corn — Zea mays var. tunicata Larrañaga ex A. St. Hil.
• Striped maize — Zea mays var. japonica