Rice right, except for the part where nodes are cylindrical and hollow. Plant height is 60 to 200 cm. In addition to the main stem of rice, 4 to 5 Shoot minor. Rice leaves are alternate in two rows on either side of the stem. Rice leaf sheath, blade, ligule and is stipules. Such as wheat and rice, is thyrsoid the seeds in the fall.
Unlike wheat, barley and maize spikelets that are compact and close together, uncompressed rice spikelets on major and minor axes of the inflorescence is. Fruits sheath white rice, brown, amber, red or purple, the fruit with its sheath, called rice. For rice for human use, should be peeled rice, the grains are separated from their pod.
Rice cultivation in different parts
Evidence shows that around 4000 BC, in India and China, rice cultivation has been common. After wheat, rice is considered the second most important cereal in the world. Nearly 90 percent of the area under cultivation and production to the Far East is rice. More than half of the rice crop is produced in India and China. In general, tropical and subtropical countries, Burma, Thailand, Vietnam, Laos, Indonesia, Philippines, Pakistan, India, America, Japan, Italy, Egypt, China, Brazil, Cuba, Mexico and Australia are the producers of rice.
Rice cultivation in Iran
Rice cultivation in the northern areas, particularly in city and province has a long history. Evidence suggests that this product in this area for centuries before the birth of Christ and has spread at the time of the Achaemenids. Today, due to the growing population, domestic rice production to meet the needs of the people and for this reason, significant quantities of the product imported from abroad.
Rice a year on favorable climatic conditions capable of regrowth after harvesting the first, second and sometimes even to a series of product launch and product manufacturers. Wild rice a year at high altitudes or non-permanent swamps grow shallow. Rice a year are generally more resistant to drought. Wild rice in lowlands and swamps Perennial often grown permanent.
Appropriate conditions for the cultivation of rice
Temperature: The temperature needs to be between 20 and 37 ° C the rice grow. Low temperatures early in the growing season or farm irrigation with cold water causes the delayed ripening seeds. The high temperature also reduces the number of spikelets are fertile and grain weight.
Light: Light is one of the factors affecting plant growth. Light intensity at the beginning of the season limiting factor for the growth of rice may be taken into account. But toward the end of the growing season, especially during the formation of clusters, increased competition for light between plants.
Humidity: appropriate amount of moisture for rice flowering plants, 70 to 80 percent. Humidity less than 40%, considered a deterrent for flowering plants. Wind and rain and hail, at the time of flowering is detrimental. When harvesting operations as well as significant delays in drying. Rice, whole plant is hydrophilic, but not water. Aquatic plants such as roots and root hairs is unable to produce. While the rice roots and root hairs minor fatal.
Water: Water is needed rice and other grains. Eighty percent of the water required for rice produced in the world, particularly in tropical areas, rain water is provided. The remaining 20% of the river water and well water supply as well. The results show that if the water temperature is less than 19 ° C, seed arrival time delayed. If more than 30 degrees, root development and yield of rice due to the limited amount of oxygen in the water is low and decreased plant efficiency.
Soil: rice in different soils, from poor to rich that only water is needed to supply the plant comes into operation. The amount of water in the soil is lighter than heavy soils. The best soil for rice cultivation, impervious clay layer at a depth of 50 to 150 cm and with plenty of organic matter. Rice primarily to soil salinity and salt water resistant. If there is enough water to wash soil salt, rice can be used to improve soils.
Direct method: to sow seeds directly into the soil.
Transplanting method: seed soaked into the earth to sow the treasury and then, plants or seedlings obtained shall be transferred to the main land farm.
Fertilizers for rice
Rice, other grains such as nitrogen to show good response. As well as ammonium and nitrate nitrogen is absorbed. On the other hand, phosphorous fertilizers, root growth and plant resistance against diseases and potassic fertilizers, assimilate from leaves to other members of the plant, especially the seeds, as well as plants increase endurance.
Diseases and pests
Pyricularia oryzae fungus causing the disease. One of the most destructive diseases of rice plants that are drying up, break down the stem is able to significantly reduce the amount of rice. Farm spraying with copper sulfate and organic mercury compounds are effective in controlling the disease to some extent.
Rice crown rot
It is also known that Zhygantysm, caused by the fungus Gibberia fugikuria the fungus, due to its extraordinary growth stems and thin and eventually death of the plant is rice. Temperatures over 20 ° C, especially in the top layer of soil can provide favorable conditions for the activity of the fungus. Agrvzan seed disinfection can reduce the damage caused by this fungus.
Harvest time according to the temperature is usually between July and August to late November or early December start continues. When the harvest, 80% of leguminous seeds (rice) located in the upper part of the cluster and yellow leaves and seeds are hard. Seeds usually begin one to two weeks of hard leaves are yellow. The grain moisture content of the measure is taken. Grain moisture content should be between 20 to 35 percent. In some countries, including Iran, harvests using DOS do. Grapes cut in batches and leave to dry. After drying, the rice is ready for the process.
The outermost layer is called the pericarp rice very hard and transparent. Under this section the grain of the skin that are rich in protein and fat, but it is a poor starch. After skin Lvrn layer that is part of the endosperm. So the act of peeling, much of the nutrients lost rice. Most people eat rice in Asia. The food is perfect, because it is very low in protein and amino acids. Rice is gluten, the main protein Avryznyn (oryzenin) is.
Combine rice, starch is mainly located in the endosperm. Brnjhayy that Mylv more pectin and expansion of more efficient cooking time low. After boiling the rice and stew with meat, fish and vegetables they desire. In the preparation of starches, sweets it is used. In the countries where exclusively use rice as grain, various diseases such as beriberi, malnutrition, decreased growth of the decrease can be seen in the labor force. Rice and other grains should be consumed. Because its use alone does not meet all the nutritional requirements of the body.