Sorghum Diseases in India

elated to the abundant formation of conidia
when conditions are warm and moist. (Bandyopadhyay
1986).
Panicle diseases
Grain molds and weathering effects are major
problems with introduced genotypes maturing
during relatively high rainfall. Long smut is
more severe in the Sudanian and southern
Sahelian zones.
Parasitic weeds
As with some locals, many introduced sorghums
are susceptible to Striga. Identifying unequivocally
stable lines resistant to Striga is a
complex process.
Research efforts
Study of the development of gray leaf spot,
sooty stripe, and leaf anthracnose in various introduced
genotypes and the effect on grain yield
is now underway. The work on sooty stripe and
leaf anthracnose is in collaboration with the National
Program of Burkina Faso. More basic
work on the biology of the fungi and the epidemiology
of these diseases is planned. The major
objective is to understand these diseases in
order to develop effective screening techniques.
Effort is being made to identify sources of resistance
to these diseases through a regional nursery.
Preliminary inheritance studies suggest that
susceptible reaction to gray leaf spot and resistance
to leaf anthracnose are dominant (Murty
and Thomas, unpublished data 1987).
ICRISAT's sprinkler irrigation method for
grain mold screening has been successfully
tested for 2 years at Farako-Ba, Burkina Faso.
This technique will now be used to routinely
screen genotypes for grain mold in western
Africa.
Soil shading with a nonerect spreading
groundnut line (59-426) has proved successful
in reducing Striga in several of our experiments
conducted in farmers' fields in 1986 and 1987.
Differences in soil temperature and moisture between
shaded and unshaded plots were negligible
(Thomas, M.D., unpublished data 1986,
28
1987). Work will continue on the mechanism of
Striga suppression, using crops in addition to
groundnut.
In a limited survey of five localities, the National
Program of Burkina Faso has determined
that the most common species of fungus found
in sorghum seeds is Colletotrichum gratninicok,
the anthracnose fungus. Many Curvularia species
were detected in all parts of the grains, including
the embryo (Kabore and Couture 1983).
Using the toothpick method, Neya, and Kabore
(1987) observed between 7, 9, and 46% loss in
grain yield of Gnofing, a Burkina Faso local variety.
They showed a positive correlation between
leaf and stem anthracnose.
In Senegal, Louvel and Arnaud (unpublished
data) suggested that grain mold resulted in poor
germination of seeds and poor seedling vigor.
Fusarium spp and Curvularia spp were the dominant
fungi in the molded grains they studied.
Acknowledgment. I wish to thank Y. Paco and
A. Neya of the National Program in Burkina
Faso for their help in our studies on sooty stripe
and leaf anthracnose, respectively.
References
Bandyopadhyay, R. 1986. Sooty stripe. Pages 13-
14 in Compendium of sorghum diseases (Frederiksen,
R.A., ed). St. Paul, MN 55121, USA:
The American Phytopathological Society.
Frederiksen, R.A. 1984. Disease problems in sorghum.
Pages 263-271 in Sorghum in the Eighties:
proceedings of the International Symposium on
Sorghum, 2-7 Nov 1981, ICRISAT Center, India.
Patancheru, Andhra Pradash 502 324, India: International
Crops Research Institute for the Semi-
Arid Tropics.
Kabore, K.B., and Couture, L. 1983. Mycoflora
des semences du sorgho cultive en Haute-Volta.
(In Fr. Summary in Eng). Le Naturaliste Canadien
110:453-457.
Neya, A., and Kabore, K.B. 1987. Mesure de l'incidence
de l'anthracnose et de la pourriture
rouge des tiges causes par le Colletotrichum
graminicota chez le sorgho. (In Fr. Summary in
Eng.). Phytoprotection 68:121-126.