Sorghum Diseases in India

Other Diseases
Numerous other diseases, to be mentioned here
only briefly, have been reported for pearl millet:
[Luttrell (1954); Ramakrishnan (1963); Ferrais
(1973); Wells and Hanna (1987)]. Some are important,
but generally only on a localized basis;
most seem to be of little concern.
Fungal pathogens reported to cause seedling
blights or leaf diseases include one or more species
of the following genera: Beniowskia, Cercospora,
Curvularia, Dactuliophora, Fusarium, Gloeocercospora,
Helminthosporium (a group of several
genera and species), Phoma, Placosphaeria, Pyricularia,
Ramulispora, Rhizoctonia, and Sclerotium.
False mildew (Beniowskia sphaeroidea)
seems limited to parts of southern and eastern
Africa, and circular leaf spot (Dactuliophora elongata)
may be limited to the higher rainfall areas
of pearl millet cultivation in western Africa.
Several bacteria have been reported as leaf
pathogens on pearl millet. These diseases are
generally of minor importance, but there is a
need for accurate identification of the bacteria
involved. Recent research on two bacterial diseases
in Africa, bacterial leaf stripe (Claflin et al.
1987) and bacterial leaf streak (Qhobela and
Claflin 1987) may help to clarify the situation.
Preharvest molding of grain can occur and
even cause considerable damage when unusually
wet conditions prevail at the time grain
approaches physiological maturity, or when harvesting
is delayed. However, grain molding is
not a common problem of pearl millet in its major
production areas. Some fungi associated with
grain molding are species of Cladosporium, Curvularia,
Fusarium, Oidium, and Helminthosporium.
Charcoal rot (Macrophomina phaseolina) does
occur in pearl millet, and Fusariurn spp have
been found associated with pearl millet stalks.
However, from the lack of information available
on stalk and root rots of pearl millet, it is perhaps
reasonable to assume that these diseases
are of less importance to pearl millet production.
Conclusion
Considerable progress has been achieved in understanding
the biology and epidemiology of at
least the major pathogens and diseases of pearl
millet. Large-scale field screening techniques,
having a moderate to high degree of reliability,
have been developed for most of the major diseases,
and resistances have been identified.Some
networks for multilocational testing have been
established and others are being developed.
Breeding for resistance to many diseases is
progressing.
These achievements are significant, but much
research remains to be done along these and
other lines. Improvement of screening methodologies
to provide efficiency, reliability, and
suitability for breeding is an urgent need. Hotspot
locations alone are not sufficient for screening.
Speed of progress in breeding for resistance
will depend to a large degree on the extent of
collaboration between breeders and pathologists.
Human and material resources for pathology
research in pearl millet are often very limited,
and care should be taken that these resources
are directed toward research that has the best
chance of success in benefiting the farmer. These
resources are in shortest supply in the major
geographic areas of pearl millet cultivation, in
the zone spanning from Sudan to Senegal. Williams'
survey of journal articles on pearl millet
diseases published in the Review of Plant Pathology
(1984b) (formerly the Review of Applied
Mycology) from 1971 to 1980 is worth noting. He
reported that 8024 articles were published on
diseases of five major cereals (wheat, rice, maize,
sorghum, pearl millet) during this 10-year period;
of these, only 149 (2%) dealt with pearl
millet. Furthermore, only 5 of these originated in
Africa, whereas 129 were from India and the remaining
15 were from other countries.
References
Ajrekar, S.L., and Likhite, V.N. 1933. Observations
on Tolyposporium penicillariae Bref. (the bajra
smut fungus). Current Science 1:215.
Andrews, D.J., King; S.B., Whitcombe, J.R.,
Singh, S.D., Rai, K.N., Thakur, R.P., Talukdar,
B.S., Chavan, S.B., and Singh, P. 1985a. Breeding
for disease resistance and yield in pearl millet.
Field Crops Research 11:241-258.
Andrews, D.J., Rai, K.N., and Singh, S.D.
1985b. A single dominant gene for rust resistance
in pearl millet. Crop Science 25:565-566.
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