Production trends

Trends in overall output

Global sorghum production fell by 0.7 percent per annum between 1979 and 1994 (Table 2, and Fig. 3), in contrast to annual increases in the production of other major grains: wheat (1.8 percent), rice (2.3 percent) and maize (1.7 percent). During this period, production grew in Africa (2.9 percent), but declined in most other parts of the world, particularly in North and South America (Table 2).

In the majority of Group I (developing) countries, increases in total output remained below population growth (Table 2). Consequently, per caput production declined during the 1980s before recovering partially in the early 1990s.

Figure 3. Global trends in sorghum production, 1979-94.

Table 2. Sorghum growth rates, 1979-94.

		Area (%/yr)	Yield (%/yr)	Production (%/yr)	Per caput production (%/yr)
Developing countries		0.1	-0.5	-0.4	-2.4
Africa		3.9	-1.0	2.9	0.0
Northern Africa		3.9	-1.1	2.8	0.2
	Sudan	4.2	-0.9	3.3	0.8
Western Africa		5.7	-1.2	4.5	1.5
	Burkina Faso	2.5	3.2	5.8	2.9
	Mali	6.3	-0.1	6.2	4.4
	Niger	8.2	-5.9	1.8	-2.2
	Nigeria	6.7	-2.1	4.4	1.4
Central Africa		2.1	0.9	3.1	0.0
Eastern Africa		-0.2	-0.6	-0.8	-3.6
	Ethiopia	-1.0	-0.7	-1.7	-4.4
	Kenya	-1.5	2.4	0.8	-2.7
	Mozambique	2.0	-4.9	-3.0	-4.6
	Somalia	-1.3	0.6	-0.7	-3.2
	Tanzania	0.5	-0.2	0.3	-2.8
	Uganda	2.8	-1.0	1.8	-1.5
	Zimbabwe	-1.3	1.3	-0.0	-3.2
Southern Africa		3.0	-2.2	0.7	-2.2
Asia		-2.6	1.5	-1.1	-3.0
Near East		-2.8	3.2	0.3	-2.6
	Saudi Arabia	-0.9	7.7	6.7	2.3
	Yemen	-2.8	1.6	-1.3	-4.7
Far East		-2.5	1.4	-1.1	-2.9
	China	-5.8	3.6	-2.5	-3.8
	India	-2.1	1.7	-0.5	-2.5
	Pakistan	0.1	0.1	0.3	-3.1
	Thailand	-2.4	1.5	-0.9	-2.3
Central America and the Caribbean		-0.4	-0.1	-0.6	-2.7
	El Salvador	0.5	1.7	2.3	0.8
	Guatemala	4.1	-4.0	-0.0	-2.8
	Haiti	-2.6	-0.0	-2.6	-4.4
	Mexico	-0.4	-0.2	-0.6	-2.8
	Nicaragua	0.2	0.0	0.3	-2.5
South America		-5.9	0.6	-5.4	-7.2
	Argentina	-9.6	1.4	-8.3	-9.6
	Brazil	4.1	-0.9	3.1	1.2
	Colombia	0.1	2.8	2.9	1.0
	Uruguay	-4.5	3.9	-0.9	-1.4
	Venezuela	0.0	2.0	2.1	-0.3
Developed countries		-2.6	1.2	-1.5	-2.5
	Australia	-1.9	-0.1	-2.0	-3.4
	EC	-0.0	1.6	1.5	0.0
	South Africa	-4.1	1.8	-2.4	-4.8
	United States	-2.7	1.3	-1.5	-2.4
CIS1		0.5	-3.5	-3.0	-4.6
World		-0.2	-0.5	-0.7	-2.5

1. Until 1991, area of the former USSR. Source: FAO

Source: FAO

Within Group I there were two distinct trends. In Asia, production has fallen over the past decade (Fig. 3), largely because of sharp declines in area and production in China. In India, production grew by almost 5 percent per annum during the 1970s, but has remained unchanged during the past decade as sorghum has been replaced by more profitable crops such as pulses and oilseeds. The loss in area was partly compensated by higher productivity obtained by using improved varieties and fertilizer; yields climbed steadily from around 650 kg/ha in the early 1970s to just under 900 kg/ha currently. In Africa, in contrast, production increased, particularly during the first half of the 1980s. This increase was due to area expansion into drier lands as a result of population growth; yields, in fact, fell during the period.

In Group II (developed countries, Argentina and Mexico) production fell by almost 40 percent during the latter half of the 1980s, essentially because policy interventions led to reductions in sorghum area. In the United States, output has nearly halved over the past 10 years. During 1985-88, sorghum area in the United States fell from 6.8 million to 3.7 million hectares as a result of two major events.

(i) Farm legislation enacted in 1985 lowered support prices for sorghum compared to cotton or maize (the main competing crops), introduced the interchangeability of sorghum and maize base areas, made crop insurance benefits lower for sorghum, and allowed sorghum growers to idle large areas. Together, these changes encouraged farmers to replace sorghum with other crops.

(ii) Relatively more drought-tolerant maize varieties were developed, and in combination with the increased application of no-tillage technology, allowed the maize belt to extend further west into traditional sorghum land. As a result, universities and private seed companies have cut back on sorghum research.

In Argentina, sorghum production fell from 8 million tons in 1983 to 3 million tons in 1988, because there was a drastic fall in imports by the former USSR¹.

[¹. The former USSR was a large importer of maize and sorghum from the United States. Following the grain embargo led by the United States in the early 1980s, USSR began importing large quantities of sorghum from Argentina. These purchases fell drastically after the ban was lifted, as price trends favoured the purchase of maize (from the United States).]

Trends in area and yields

Sorghum is currently grown on 45 million hectares worldwide (1992-94 average, Table 1). The cropped area is expanding in Africa, where it grew from 13 million to almost 22 million hectares between 1979-81 and 1992-94 (Fig. 4). However, the area is declining elsewhere; global sorghum area fell by 0.2 percent per annum between 1979 and 1994 (Table 2). South America was the most affected, mainly as a result of developments in Argentina.

As for most crops, sorghum yields have risen as new technologies (improved varieties, higher input use, and to some extent better resource management and disease/pest control) were developed and disseminated. The exception is Africa, where yields fell by 14 percent during the 1980s before rising once more in the early 1990s (Fig. 5). In India, yields vary significantly between regions, depending on rainfall, soil type and season. Yields of rainy-season sorghum are 2-2.5 t/ha in areas with deep soils and assured rainfall, but postrainy-season yields are less than 500 kg/ha in many low-rainfall areas.

There are sharp contrasts in productivity between regions: yields (1992-94 average) were 0.8 t/ha in Africa, 1.2 t/ha in Asia, over 4 t/ha in North America, and over 5 t/ha in Europe (Table 1). The reason for these differences is essentially the degree of commercialization and the corresponding adoption of new technologies. Mexico is a good example of dramatic growth created by large-scale commercialization. The sorghum area in Mexico rose from 0.1 million to 1.5 million hectares from the 1960s through the early 1980s. Average yields rose to over 3 t/ha, exceeding the national average for maize by one-third.

In a number of Group II countries, the use of hybrid seed, fertilizer and irrigation have ensured that yields have increased even from a high base level. By contrast, in Group I, most sorghum is produced on small, fragmented plots; sometimes intercropped, and frequently in areas where soil fertility is low. There is generally limited use of purchased inputs due to financial constraints. However, a few Group I countries (e.g., Sudan and Zimbabwe) produce part of their sorghum on large farms for commercial purposes, using high inputs and sometimes supplementary irrigation. Large commercial farmers in Zimbabwe harvest 2-3 t/ha compared to 400-600 kg/ha by traditional smallholders.

One important factor underlying yield trends is the adoption of hybrids. Hybrids are most widely used in areas where sorghum is produced commercially and in countries with a well-developed private seed industry. Correspondingly, the use of hybrids is concentrated in Group II countries.

Figure 4. Global trends in sorghum area, 1979-94.

Figure 5. Global trends in sorghum yield, 1979-94 (3-year moving average).

In most Group I countries - notable exceptions are China, India, Thailand, Sudan and Zimbabwe -the use of hybrids is negligible. Most hybrids are developed (in Group II) for feed sorghum. However, they are also being developed for the food market in some Group I countries, particularly in India, where they occupy approximately 55 percent of the sorghum area.

Falling yields in Africa, where sorghum is a key food security crop, are a major cause for concern. Population growth has forced an expansion of sorghum area, often into drier, more marginal lands. In some countries, government market policies have encouraged the reallocation of relatively productive sorghum fields to maize. To some extent, this is the result of market policies which have encouraged commercial trade and processing of maize but not of sorghum. In areas where this change has not occurred, fallow periods have often become shorter, giving the land less time to replenish nutrients. Since fertilizer application is generally very low, the net result is a decline in soil fertility. However, although yields have clearly fallen, the decline has not been as sharp as the figures (1.0 percent per year between 1979 and 1994, Table 2) would suggest. This is because the 1979-81 data are for relatively good land, while the 1992-94 figures are for a mixture of "good" and more marginal lands.

Production constraints

The majority of smallholder farmers, especially in the semi-arid tropical regions of Africa, do not produce enough sorghum to meet family requirements in most years. They see sorghum (and crop production in general) as a semi-subsistence enterprise that offers smaller returns than other investments such as livestock or school fees. As a result, they tend not to invest in fertilizers or seed of improved varieties.

Rising labour costs have also affected most farm operations, from land preparation, weeding and bird scaring to harvesting and grain processing. Another factor, important throughout Asia and in urban areas in Africa, is changing food preferences. As incomes rise, consumers tend to purchase wheat, rice and in some cases maize, rather than traditional coarse grains.

In some areas production is constrained by birds, which attack the crop particularly during the grain-filling stage. To minimize bird damage, sorghum with a purple undercoat is cultivated in some countries. The undercoat contains tannins, bitter, stringent substances (polyphenols) that are distasteful to birds. However, most varieties grown in Africa and Asia do not contain tannin and are, therefore, susceptible to bird damage.

Another major constraint to sorghum production is Striga, a parasitic weed that attaches itself to the sorghum roots from where it draws its moisture and nutrient requirements, inhibiting plant growth, reducing yields and in severe cases, causing plant death. Some Striga-resistant sorghum varieties have been developed, but these generally offer lower yields than traditional cultivars and improved (but Striga-susceptible) varieties.

Grain moulds cause significant losses in both grain yield and quality, particularly in areas where improved cultivars have been adopted². Other important diseases include anthracnose, charcoal rot, downy mildew, ergot and leaf blight. Insect pests constrain production in many areas. Stem borers are endemic in all areas; head bugs and midge are most important in Western Africa; and shoot fly causes substantial losses in late and off-season sowings in both Asia and Africa.

[². Most improved varieties mature earlier than local varieties, often before the end of the rainy season. This results in increased susceptibility to grain moulds, greatly limiting the adoption of these varieties.]

Another major problem is that variable rainfall leads to large fluctuations in production. Prices fall abruptly in good years, leaving traders reluctant to enter the market, especially since stockholding infrastructure is usually inadequate. This increases the price risk that sorghum producers face, and their unwillingness to invest in commercial sorghum production.

Inadequate government policy support also limits the expansion of sorghum output in many Group I countries. For example, in Africa, as government production support measures for sorghum are relatively small compared to maize, the latter encroached onto sorghum land. In Asia, particularly in India, irrigation and fertilizer subsidies have increasingly favoured rice, wheat and cash crops at the expense of coarse grains, while procurement policies for rice and wheat have helped to increase to a large extent the area under these crops. In a number of developing countries that had long-standing price support policies for sorghum, this support has been drastically reduced or eliminated, mainly as a result of market deregulation.