Sorghum Diseases in India
Sorghum Diseases in India
Sorghum Diseases in India
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Resistance to ergot <strong>in</strong> pearl millet, especially <strong>in</strong> the hybrids, rema<strong>in</strong>s elusive. Because of health<br />
hazards associated with ergot, <strong>in</strong> addition to reductions <strong>in</strong> yield, adoption of hybrids is restra<strong>in</strong>ed.<br />
Innovative strategic and basic research is needed to tackle this disease. Biotechnology may offer an<br />
avenue; the possibility needs exam<strong>in</strong>ation.<br />
Smut and rust of millet are not so <strong>in</strong>tractable as ergot and downy mildew, but even so, <strong>in</strong>ternational<br />
cooperation <strong>in</strong> mak<strong>in</strong>g use of sources of resistance and evaluat<strong>in</strong>g the f<strong>in</strong>al products of<br />
breeders' fields is <strong>in</strong> order. Of course, this is not possible without jo<strong>in</strong>t research by pathologists and<br />
breeders, work<strong>in</strong>g side by side.<br />
It seems that nematodes are affect<strong>in</strong>g millet <strong>in</strong> sandy soils of western Africa. I do not know if this<br />
pest is receiv<strong>in</strong>g the attention of pathologists, or of the entomologists, or if it is be<strong>in</strong>g passed over by<br />
both.<br />
Some disease problems are amplified by nutritional and drought stress. Stalk rot of sorghum and<br />
Striga <strong>in</strong> sorghum and millet are typical cases. Pathologists, breeders, and plant nutritionists/agronomists<br />
work<strong>in</strong>g together could be very effective <strong>in</strong> develop<strong>in</strong>g varieties or techniques for manag<strong>in</strong>g<br />
Striga and stalk rot <strong>in</strong> sorghum and millet.<br />
In our research <strong>in</strong> diseases, we have not made adequate use of biochemistry. I understand ergosterol<br />
content <strong>in</strong> the gra<strong>in</strong> is a good <strong>in</strong>dicator of colonization of gra<strong>in</strong> by gra<strong>in</strong> mold fungi; also an<br />
elevated content of 2-4 flavanol <strong>in</strong> the gra<strong>in</strong> and even <strong>in</strong> the leaves and stems is a measure of the<br />
ability of a genotype to resist molds. Could such techniques be used rout<strong>in</strong>ely <strong>in</strong> screen<strong>in</strong>g for<br />
resistance?<br />
I know that plant pathologists will name large numbers of sorghum and millet diseases <strong>in</strong> each<br />
ecological zone, but we must develop a practical approach to identify and prioritize the most serious<br />
diseases as targets of research <strong>in</strong> the next decade. Our major efforts should be the transfer of multipledisease<br />
resistance to agronomically superior genotypes, or development of a system of disease management<br />
which is practicable and economical to use, even by resource-poor farmers.<br />
The ideas and f<strong>in</strong>d<strong>in</strong>gs promulgated <strong>in</strong> this book should lead to development of collaborative<br />
projects between national programs, ICRISAT, INTSORMIL, and <strong>in</strong>stitutes <strong>in</strong> the developed countries<br />
for applied, strategic, and basic research on priority diseases. Active participation and <strong>in</strong>put <strong>in</strong>to the<br />
Cereal Cooperative Research Networks (CCRNs) by pathologists of the national research organization<br />
is essential, as it is these scientists who are <strong>in</strong> the best position to record and report the <strong>in</strong>cidence<br />
of a disease and the identities of genotypes resistant to it. Screen<strong>in</strong>g for disease resistance at hot spots<br />
and use of standard techniques <strong>in</strong> evaluation is essential, so as to get useful data. ICRISAT has a gene<br />
bank with more than 30 000 accessions <strong>in</strong> sorghum and 19 000 accessions <strong>in</strong> pearl millet. It is a rich<br />
source, which needs to be exploited for its sources of resistance to diseases and the other desirable<br />
traits that enable crop improvement.<br />
Our tra<strong>in</strong><strong>in</strong>g facilities at ICRISAT Center is another resource for strengthen<strong>in</strong>g crop improvement<br />
<strong>in</strong> many nations of the world, <strong>in</strong>clud<strong>in</strong>g capability <strong>in</strong> disease research. I would suggest that the<br />
tra<strong>in</strong><strong>in</strong>g constra<strong>in</strong>ts <strong>in</strong> disease management be identified; this <strong>in</strong>formation will be useful to ICRISAT.<br />
Special tra<strong>in</strong><strong>in</strong>g programs can be organized to meet urgent needs.<br />
F<strong>in</strong>ally, let us not forget that sorghum and millet <strong>in</strong> the semi-arid tropics are staple foods of the<br />
peasant farmer of limited means, and he needs multiple-disease resistant and high-yield<strong>in</strong>g seed to<br />
grow. He is not <strong>in</strong>terested <strong>in</strong> pathologists' f<strong>in</strong>d<strong>in</strong>gs or breeders' claims, but he needs the product of<br />
their jo<strong>in</strong>t efforts so that he can produce crops with higher and more consistent yields year after year.<br />
viii<br />
J.S. Kanwar<br />
Deputy Director General Emeritus,<br />
International Crops Research Institute<br />
for the Semi-Arid Tropics (ICRISAT).<br />
Patancheru, A.R 502 324, <strong>India</strong>.