In this article we will discuss about:- 1. Origin of Rice 2. Rice Growing Environment 3. Domestication and Cultivation.
Origin of Rice:
Rice is the seed of monocot plants Oryza sativa (African rice) or Oryza glaberrima (African rice). This is called Cereal grain and is consumed as staple food in a large part of world’s human population.
According to data for 2010 available it is the grain with second-highest worldwide production after maize (Corn). Rice is the most important grain with regard to human nutrition and Caloric intake. It provides the calories consumed worldwide by the human species.
Rice originates from a single domestication 8,200-13,500 years ago, in the Pearl River valley region of China. Archaeological evidences show that rice was domesticated in the Yangtze River Valley region in China. From East Asia, rice, spread to south east and south Asia. It was introduced in Europe through Western Asia and to America through European colonization.
Rice is a good source of proteins and a staple food but it is not a complete protein. It does not contain all of the essential amino acids in sufficient quantity for good health and should be combined with other sources of proteins like nuts, beans, pulses, fish etc.
Rice can also be puffed or popped like corn or wheat.
Nutrient value per 100 gm is:
Energy = 1,527 kJ (365 Kcal)
Carbohydrates = 80 gm.
Sugar = 0.12 gm.
Dietary fiber = 1.3 gm.
Fat = 0.66 gm.
Proteins = 7.13 gm.
Water = 11.61 gm.
Apart from the above vitamins and minerals are as:
Thiamin (Vit B1) = 0.0701 mg (6%)
Riboflavin (Vit B2) = 0.0149 mg (1%)
Niacin (Vit B3) = 1.62 mg (11%)
Pantothenic acid (Vit B5) = 1.014 mg (20%)
Vitamin B6 = 0.164 mg (13%)
Calcium (Ca) = 28 mg (3%)
Iron (Fe) = 0.80 mg (6%)
Magnesium (Mg) = 25 mg (7%)
Manganese (Mn) = 1.088 mg (52%)
Phosphorus (P) = 115 mg (16%)
Potassium (K) = 115 mg (2%)
Zinc (Zn) = 1.09 mg (11%)
Rice is the staple food and dietary energy source of 17 countries in Asia and the pacific, 9 countries in North and South America and 8 countries in Africa.
Rice and rice products contain Arsenic a known poison and Group 1 Carcinogen. Consumption of one serving of some varieties of rice gives more exposure to arsenic than consumption of one liter of water which contain 5 parts per billion arsenic.
The amount of rice varies widely with the greatest concentration of Brown rice and grown on land formerly used to grow cotton. There is no safe level of arsenic but in 2012 a limit of 10 parts per billion is established in US for drinking water, double the level of 5 parts per billion was originally proposed by EPA.
FDA (Food and Drug Administration) of US is further extending it. China has set a limit of 150 ppb for arsenic in rice.
Rice Growing Environment:
Rice can grow in environment depending on water availability. It thrives generally in water logged area. It can also survive floods.
The various environments are:
a. Lowland, rain-fed:
Drought prone, medium depth, waterlogged, flood prone and submergence
b. Lowland, irrigated:
In both wet season and dry season.
c. Coastal Wetlands:
d. Deep water:
Deep water or floating rice.
e. Upland rice or Ghaiya rice:
Well known for its drought tolerance.
Domestication and Cultivation of Rice:
The genetic evidence published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS) suggested that all forms of Asian Rice (Indica and Japonica) come from domestication as early as 8,200-13,500 years in China of the wild rice Oryza rufipogon.
In 2012 a study published in Nature through a map of rice genome variation, indicated that the domestication of rice occurred in the Pearl River Valley region of China. The rice was spread from East Asia to South and Southeast Asia. Previous evidences show that rise was first domesticated in the region of Yangtze River Valley is China.
The major rice producing countries of Asia are China, India, Indonesia, Vietnam, Bangladesh, Pakistan, Philippines, Myanmar, Thailand and Japan. Rice is the staple food amongst all the ethnic groups in Sri Lanka. The state mainly depends on rice cultivation. The principal cultivated season is called ‘Maha’ (from October to March), while the subsidiary cultivation season is known as ‘Yala’ (From April to September).
In Africa the rice cultivation started about 3,500 years back. Between 1500 and 800 BC. Oryza glaberrima propagated from its original centre i.e. Niger River Delta extending upto Senegal. The Asian species were introduced to East Africa and spread west ward. African rice helped Africa conquer its 1203 famine.
Rice was known to the classical world being imported from Iran, Egypt and West Asia. Large deposits of rice since the first century A D had been found in Roman Camps in Germany. The soldiers returning from Asia to Greece after Alexander the Great’s military expedition brought rice from Asia. The Moors brought Asiatic Rice to the Iberian Peninsula in 10th century. This rice was grown in Valencia and Majorca.
In Majorca rice cultivation was stopped after Christian conquest. Muslims brought rice to Sicily before 1475. Its cultivation was promoted by Ludovico Sforza, Duke of Milan and demonstrated in his model farms. After 15th century, rice spread throughout Italy and France. In European Russia, rice has been grown in the Krasnodar Kari and was called in Russia as ‘Rice from Kuban’.
Rice was grown is some areas of Southern Iraq. It moved north to Nisibin with the rise of Islam. From north it moved to southern shores of Caspian Sea in Iran and then into valley of Volga. In Egypt rice is grown is the Nile Delta. In Palestine the rice was introduced is Jordan Valley. Rice is also grown is Saudi Arabia at Al-hasa Oasis and Yemen.
It is one of the earliest crops grown is Australia by British Settlers, who had experience with rice plantations in the Americas and the subcontinent.
In united States, colonial south and Georgia grew and amassed wealth from slave labour from the senegambia area of West Africa and from Coastal Sierra Leone.
At the port of Charleston through which 40 percent of all American slave imports passed, slaves from this region of Africa brought the highest prices, in recognition of their prior knowledge of rice culture, which was put to use on many rice plantations around Georgetown, Charleston and Savannah.
In 1964 rice arrived in South Carolina probably originating from Madagascar. More than 100 varieties of rice are commercially produced in six states i.e. Arkansas, Mississippi, Missouri, Louisiana, Texas and Califronia.
Caribbean and Latin America:
Rice is not native to America but was introduced to Latin America and the Caribbean by European colonizers at an early date with Spanish colonizers introducing Asian rice to Mexico in 1520 at Veracruz and the Portuguese and their African slaves introducing it at about the same time to Colonial Brazil.