Sorghum Diseases in India

Sorghum Diseases in Southern Africa
W.A.J. de Milliano 1
Abstract
In the last 15 years, 10 of the 12 countries of southern Africa have produced about 12 to 15% of the
continent's sorghum grain harvest; this is about 2 to 3% of the world's production. Tanzania,
Republic of South Africa, Mozambique, and Zimbabwe had the largest areas under production.
National grain yields were low and only occasionally exceeded 1 t ha -1 . There is no indication that
fluctuation in hectarages devoted to sorghum, grain yields, or total production are due to high
disease incidence. During this period, varieties and hybrids have begun to replace landraces.
There is still a need to identify the diseases of sorghum in southern Africa, and study their
occurrence and incidence. Data showing losses caused by diseases are not available. The southern
African nations have many ecological zones and some countries have as many as 20 diseases.
Witchweeds, covered smut, downy mildew, leaf blight, sooty stripe, grain molds, anthracnose, rust,
charcoal rot, and ergot, all are considered to be of importance. Incidence of ergot and virus diseases
appear to be on the increase. Disease research in relation to sorghum improvement was stimulated
by the initiation of the SADCC/ICRISAT Sorghum and Millets Improvement Program in 1984.
The present status of information on diseases and research results is reported and areas for further
research are proposed.
Introduction
In the last 15 years, sorghum has been grown in
the 12 countries of southern Africa for its grain,
sweet stems, and total biomass. Mozambique,
South Africa, Tanzania and Zimbabwe have the
largest areas under production (Table 1). Annual
production by 10 of these nations, from 1969 to
1986, was approximately 12% to 14% of all sorghum
grain produced in Africa. This represents
approximately 2 to 3% of the total world production.
Production data from Angola and Namibia
are not available.
The area under production appeared to be
stable in Lesotho and Malawi, and showed increases
in the Republic of South Africa and in
Zaire (Table 1). Tanzania more than doubled its
sorghum area. In Zimbabwe, the area sown to
sorghum in 1979-81 was only about one-half
that sown during the 1969-71 seasons, but sowings
during the 1984-86 seasons had increased
to more than two and approximately tripled between
1979 and 1983 harvest years to the 1974
area (Central Statistical Office 1987, p. 147). The
causes for these changes may include:
1. Farmers' response to successive droughts (according
to Tanzanian scientists).
2. Economic factors, e.g., relative price of sorghum
compared to maize (Central Statistical
Office 1987, p. 147).
3. The availability of improved varieties (such
as Serena, Dwarf Lulu, and Tegemeo in Tanzania
and hybrids such as DC 99 and DC 75
in Zimbabwe), that encouraged farmers to
grow sorghum.
4. Successful extension and promotion via mass
communication.
1. Principal Cereals Pathologist, SADCC/ICRISAT Sorghum and Millets Improvement Program, P.O. Box 776, Bulawayo, Zimbabwe.
Present address: Section Leader, Phytopathology, Zoaduniz Westende 62, PO Box 26, 1600 AA Enkhuizen, The
Netherlands.
de Milliano, W.A.J. 1992. Sorghum diseases in southern Africa. Pages 9-19 in Sorghum and millets diseases: a second world
review. (de Milliano, W.AJ., Frederiksen, R.A., and Bengston, G.D., eds). Patancheru, A.P. 502 324, India: International Crops
Research Institute for the Semi-Arid Tropics. (CP 731)
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