Sorghum Diseases in India

develop technologies that can enable farmers to
treat their own seeds.
Ahmed Sheikh: In Somalia, at the Bonka Research
Station, we found that Femasan D ® is
very effective against covered kernel smut. We
plan to give out or sell 10-g sachets to farmers.
We find that the disease is very low in the research
area and in farmers' fields where they use
Fernasan D ® .
Balasubramanian and Duncan: Could you categorize
the different isolates of Colletotrichum
graminicola into specific groups based on their
reaction to differential sorghum lines?
Hulluka: There is not much information on categorizing
pathogens of C. graminicola in eastern
Africa. Based on studies conducted in Ethiopia,
we have identified three pathotypes differing in
their reaction on a set of differential varieties
obtained from Texas.
Anahosur: Is Macrophomina phaseolina the only
pathogen associated with charcoal rot?
Hulluka: In Ethiopia, Macrophomina phaseolina
causes charcoal rot.
Obilana: Specifically, damage from Striga is one
pest problem that is accentuated by changes in
genotypes and farming systems. In Sudan and
India, the introduction of improved genotypes
has been followed by an increase in Striga incidence
and damage.
Njuguna: Are there landraces that you may
have noticed in farmers' fields that are resistant
to long smut?
Thomas: There may be some landraces that are
resistant to long smut, as the incidence is low in
the farmers' fields.
Theuri: In your talk on diseases in western Africa,
you did not mention virus or virus-like diseases
on sorghum. Does this indicate that these
diseases are not present, or that sorghums are
not grown in the highland areas where virus
diseases occur?
Thomas: I have not observed virus or virus-like
diseases on sorghum in western Africa, al­
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though a virus disease has been reported from
Nigeria.
Vidyabhushanam: Many of the improved lines
and breeding lines being developed in India are
rated as resistant to foliar disease; some of these
should be screened in your region to identify
sources of resistance to these diseases.
Thomas: Certainly the lines from India can be
screened in western Africa for leaf diseases. In
fact, we have noticed that some of these lines
show susceptible reaction to gray leaf spot, leaf
anthracnose, and sooty stripe in western
Africa.
Vidyabhushanam: Framida is mentioned as
Striga-resistant in the literature.
Thomas: The situation with Striga and Framida
is not clear. Framida is tolerant to Striga, but our
evidence is incomplete. That is, yield potential
remains the same in spite of high levels of Striga.
In some locations, for example in northern Togo,
Framida supports a high population of Striga
but Framida is low compared with E 35-1 which
is clearly susceptible.
Mughogho: So far you have given us an overview
of sorghum diseases as seen by ICRISAT
scientists in the region. It would be useful to
know what research is conducted by national
programs, say, in Cameroon, Nigeria, and
Burkina Faso where we know that national sorghum
programs exist.
Thomas: Except for perhaps Nigeria, I believe
most national programs emphasize screening
available materials for resistance to the prevalent
diseases in their location.
Dangi: Breeding work on grain-mold resistance
and foliar diseases is in progress in the national
sorghum-improvement program of Cameroon.
Lines like CS 95, S 35, CS 54, and CS 61 were
identified as resistant to long smut, Striga, and
leaf diseases in Cameroon. These cultivars are
now in extension programs for on-farm testing
and adoption.
Adipala: What Striga species did you have in
western Africa? Did you use any other cover
crop apart from groundnuts?