Sorghum Diseases in India

Resistance to ergot in pearl millet, especially in the hybrids, remains elusive. Because of health
hazards associated with ergot, in addition to reductions in yield, adoption of hybrids is restrained.
Innovative strategic and basic research is needed to tackle this disease. Biotechnology may offer an
avenue; the possibility needs examination.
Smut and rust of millet are not so intractable as ergot and downy mildew, but even so, international
cooperation in making use of sources of resistance and evaluating the final products of
breeders' fields is in order. Of course, this is not possible without joint research by pathologists and
breeders, working side by side.
It seems that nematodes are affecting millet in sandy soils of western Africa. I do not know if this
pest is receiving the attention of pathologists, or of the entomologists, or if it is being passed over by
both.
Some disease problems are amplified by nutritional and drought stress. Stalk rot of sorghum and
Striga in sorghum and millet are typical cases. Pathologists, breeders, and plant nutritionists/agronomists
working together could be very effective in developing varieties or techniques for managing
Striga and stalk rot in sorghum and millet.
In our research in diseases, we have not made adequate use of biochemistry. I understand ergosterol
content in the grain is a good indicator of colonization of grain by grain mold fungi; also an
elevated content of 2-4 flavanol in the grain and even in the leaves and stems is a measure of the
ability of a genotype to resist molds. Could such techniques be used routinely in screening for
resistance?
I know that plant pathologists will name large numbers of sorghum and millet diseases in each
ecological zone, but we must develop a practical approach to identify and prioritize the most serious
diseases as targets of research in the next decade. Our major efforts should be the transfer of multipledisease
resistance to agronomically superior genotypes, or development of a system of disease management
which is practicable and economical to use, even by resource-poor farmers.
The ideas and findings promulgated in this book should lead to development of collaborative
projects between national programs, ICRISAT, INTSORMIL, and institutes in the developed countries
for applied, strategic, and basic research on priority diseases. Active participation and input into the
Cereal Cooperative Research Networks (CCRNs) by pathologists of the national research organization
is essential, as it is these scientists who are in the best position to record and report the incidence
of a disease and the identities of genotypes resistant to it. Screening for disease resistance at hot spots
and use of standard techniques in evaluation is essential, so as to get useful data. ICRISAT has a gene
bank with more than 30 000 accessions in sorghum and 19 000 accessions in pearl millet. It is a rich
source, which needs to be exploited for its sources of resistance to diseases and the other desirable
traits that enable crop improvement.
Our training facilities at ICRISAT Center is another resource for strengthening crop improvement
in many nations of the world, including capability in disease research. I would suggest that the
training constraints in disease management be identified; this information will be useful to ICRISAT.
Special training programs can be organized to meet urgent needs.
Finally, let us not forget that sorghum and millet in the semi-arid tropics are staple foods of the
peasant farmer of limited means, and he needs multiple-disease resistant and high-yielding seed to
grow. He is not interested in pathologists' findings or breeders' claims, but he needs the product of
their joint efforts so that he can produce crops with higher and more consistent yields year after year.
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J.S. Kanwar
Deputy Director General Emeritus,
International Crops Research Institute
for the Semi-Arid Tropics (ICRISAT).
Patancheru, A.R 502 324, India.