Sorghum Diseases in India

Pearl Millet Diseases in Western Africa
J. Werder 1 and S.K. Manzo 2
Abstract
Downy mildew (DM) is an important disease, followed in importance by smut. Ergot is found, but
this disease is generally confined to pearl millet in higher rainfall areas. Several leaf diseases occur,
including leaf blast, rectangular leaf spot, circular leaf spot, and three bacterial diseases, but these
are of minor importance.
Downy mildew infection is often characterized by green ear symptoms. Virulence differences
have been demonstrated for the DM pathogen; nurseries are currently in use to study virulence
and resistance stability of western African materials. Smut is especially common on panicles with
poor exertion, and infection is highest when the boot-leaf stage coincides with rainfall and high
humidity.
Striga hermonthica is especially serious in areas of low soil fertility. Local varieties show some
tolerance, but good evidence for resistance is lacking. Control of this parasite will require integrated
efforts of scientists of several disciplines.
Introduction
Pearl millet [Pennisetum glaucum (L.) R. Br.] is the
principal staple cereal grown in the dry semiarid
Sahelian regions of western Africa. The major
pearl millet growing areas of the world are
Africa, with 15.09 million ha (12.85 million in
western Africa) (Table 1), and southern Asia
with 11.34 million ha (ICRISAT 1987a).
More than 50 fungal, bacterial, and viral
pathogens of pearl millet have been reported
(Ferraris 1973). Only a few pathogens and
weeds, however, cause major damage to pearl
millet in western Africa.The main constraints of
pearl millet production in western Africa are
physical stresses like drought, poor crop establishment,
and low soil fertility, and biological
stresses: insect pests, diseases, and weeds.
Downy mildew [Sclerospora graminicola
(Sacc.) Schroet.] and Striga hermonthica are the
most important pathogens and weed parasites
in western African pearl millet sowings. Other
diseases such as smut (Tolyposporium penicillariae),
ergot (Claviceps fusiformis), and leaf
Table 1. Area sown to pearl millet and average
yield of pearl millet in eight western African
countries.
Country
Area 1
(million ha)
Average
yield
(kg ha -1 )
Burkina Faso 0.90 424
Cameroon 0.50 761
Chad 1.15 404
Ghana 0.14 NA 2
Mali 1.36 692
Niger
Nigeria
Senegal
3.08
4.72
1.00
423
565
449
Western Africa 12.85 531
Africa 15.09 564
1. Source: ICRISAT 1987b, 2. NA = Not available.
spots—though of minor importance can cause
yield losses in certain areas or on certain
germplasm.
1. Principal Millet Pathologist, ICRISAT Sahelian Center, B.P. 12404, Niamey (via Paris), Niger.
2. Head, Plant Protection Department, Institute of Agricultural Research, Ahmadu Bello University, Zaria, Nigeria.
Werder, J., and Manzo, S.K. 1992. Pearl millet diseases in western Africa. Pages 109-114 in Sorghum and millets diseases: a second
world review, (de Milliano, W.A.J., Frederiksen, R.A., and Bengston, G.D., eds). Patancheru, A.P. 502 324, India: International
Crops Research Institute for the Semi-Arid Tropics. (CP 734).
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