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Genetic diversity in rice production: past contribution and the potential of utilization for sustainable rice production - M. Rai

Secretary, DARE[31] and Director-General, ICAR,[32] New Delhi, India

GLOBAL RICE PRODUCTION SCENARIO

Of all the staple food crops, rice accounts for the dietary energy requirements of almost half the world population. Over 90 percent of the world’s rice is produced and consumed in Asia. It is the second most important crop in the world (after wheat, which has an annual cultivation area of 213 million hectares [Mha]) and is grown annually on 151.54 Mha, with an annual production of 593 million tonnes (Mt) and an average productivity of 3.91 t/ha (FAOSTAT, 2002). The four decades since 1961 have seen an increase in area, production and productivity of rice of 31.2, 174.9 and 109.7 percent, respectively. Besides Asia, rice is grown in Africa, Latin America, the United States and Australia. It is also grown to a very limited extent in the European Union. This paper limits its considerations to the major rice-growing continents, namely: Asia, Africa and Latin America.

Rice is grown on 136.07 Mha in Asia, 7.67 Mha in Africa and 5.09 Mha in Latin America. Annual rice production in the three continents is 539.84, 16.97 and 19.54 Mt, respectively, and average productivity 2.97, 2.21 and 2.84 t/ha. Table 1 shows the annual rate of growth of area, production and productivity for the 30-year period 1967-1997. Asia and Latin America have similar rates of growth in area, production and productivity: production increased at a rate of 2.5 percent per year, and area and productivity by 0.4 and 2.1 percent per year. Growth in these regions was equal to the rate of growth globally. However, in Africa, production increased at a rate of 2.8 percent per year, due mainly to the increase in area (2.2%/year); the annual rate of increase in productivity was low (0.6%).

The changes in area, production and productivity of rice in the three continents for each of the last four decades are given in Table 2. The total world rice area during this period increased from 125 to 150 Mha, an increase of over 19 percent. In Africa, the area under rice more than doubled from 3.5 Mha to over 7.0 Mha. In Asia, the total rice area increased from 118 to 122 Mha, i.e. an increase of just 3.22 percent. In South America, area increased from 5.04 to 5.70 Mha, i.e. an increase of around 13 percent.

TABLE 1
Average annual rates of growth (%) by continent, 1967-1997

Continent

Production

Area

Yield

Asia

2.5

0.4

2.1

Africa

2.8

2.2

0.6

Latin America and the Caribbean

2.5

0.4

2.1

World

2.5

0.4

2.1

TABLE 2
Average area, production and productivity of rice during the last four decades

Period

World

Africa

Asia

South America

Area (Mha)

1961-1970

125.30

3.48

118.83

5.04

1971-1980

139.85

4.50

128.24

6.52

1981-1990

144.60

5.39

132.58

6.87

1991-2000

150.09

7.11

122.65

5.70

% increase

19.78

104.10

3.22

13.13


Production (Mt)

1961-1970

125.30

6.11

286.10

8.62

1971-1980

139.85

7.90

360.00

11.66

1981-1990

144.60

10.02

474.75

15.04

1991-2000

150.09

15.49

471.20

18.04

% increase

19.78

153.46

64.70

109.19


Productivity (t/ha)

1961-70

125.30

1.75

2.41

1.72

1971-80

139.85

1.76

2.81

1.79

1981-90

144.60

1.85

3.59

2.20

1991-2000

150.09

2.18

3.49

3.19

% increase

19.78

24.54

44.96

85.75

TABLE 3
Area, production, productivity and MV coverage (by country)

Country

Area
(Mha)

Production
(‘000 tonnes)

Productivity
(t/ha)

Coverage under MVs
(%)

Asia

130.02

485.07

3.7

74

Bangladesh

9.85

27.53

2.8

47

China

30.37

178.25

5.9

100

India

42.04

118.40

2.8

66

Indonesia

10.64

46.24

4.3

77

Japan

2.21

14.97

6.8

100

Korea (Republic of)

1.16

7.05

6.1

100

Korea (DPR)

0.60

2.10

3.5

100

Myanmar

6.47

19.05

2.9

54

Nepal

1.45

3.49

2.4

36

Pakistan

2.11

5.27

2.5

42

Philippines

3.35

10.15

3.0

91

Sri Lanka

0.82

2.58

3.1

91

Thailand

8.48

18.45

2.2

68

Viet Nam

6.50

22.50

3.5

80

Africa

7.24

15.85

2.2

 

Egypt

0.58

4.58

7.9

n.a.

Guinea

1.09

0.92

0.8

n.a.

Côte d’Ivoire

0.45

0.70

1.6

n.a.

Madagascar

1.18

2.36

2.0

n.a.

Nigeria

1.68

3.85

2.3

n.a.

Sierra Leone

0.37

0.45

1.2

n.a.

Tanzania

0.35

0.61

1.7

n.a.

Latin America

6.80

20.03

2.9

40

Brazil

4.45

10.58

2.4

25

Colombia

0.41

1.68

4.1

87

Ecuador

0.36

1.37

3.8

59

World

146.45

534.70

3.7

 

From 1961 to 2000, world rice production more than doubled from 265 to 560 Mt. In Africa, rice production increased from 6 to 15 Mt (153% increase); in Asia it increased from 286 to 470 Mt (65% increase); and in Latin America, from 8 to 18 Mt (109% increase).

The productivity of rice worldwide increased during the same period from 2.11 to 3.75 t/ha (78% increase). In Africa, the increase was from 1.75 to 2.18 t/ha (24% increase), in Asia from 2.41 to 3.49 t/ha (45%) and in South America from 1.72 to 3.19 t/ha (86%).

Area, production, productivity and coverage under modern varieties (MV) in the major rice-growing countries of these three continents are given in Table 3; the changes in area, production and productivity from 1961 to 2001 are shown in Table 4. Despite the great improvement in productivity in all the continents and countries, a vast gap still exists; even the coverage under high-yielding varieties varies from 25 to 100 percent.

Detailed information is available regarding varietal development and genetic diversity from at least one country in each of the three continents: India (Rai, 1999; Mishra, 2002); Nigeria (Maji and Fagade, 2002); and Brazil (Guimaracs, 2002). See also the published proceedings of the International Symposium on Rice Germplasm Evaluation and Enhancement (Rutger et al., 1999).


[31] Department of Agricultural Research and Education.
[32] Indian Council of Agricultural Research.

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