Sorghum Diseases in India

deficit and high temperatures are conducive to
development of this disease. Late sowings (February)
in double-cropping systems in central
Brazil are also favorable to charcoal rot development.
High incidence of the disease has been
observed in some of these areas.
Because of the importance of sorghum in the
northeastern and central regions, the National
Maize and Sorghum Research Center (NMSRC)
is beginning a program to identify genotypes
resistant to this disease, hoping to incorporate
this resistance into elite cultivars. This approach
is being used at the NMSRC-Experimental Station
in northern Minas Gerais State, a semi-arid
area.
Sorghum downy mildew
The sorghum downy mildew (Peronosclerospora
sorghi) is commonly found in areas of the states
of Rio Grande do Sul, Sao Paulo, Santa Catarina,
Parana, and Minas Gerais.
Results from downy mildew trials (Table 5)
have been obtained from the states of Sao Paulo
and Rio Grande do SuL The reactions of some
sorghum genotypes in Jaboticabal-Brandes
show some to be susceptible to pathotype 4 of
Peronosclerospora sorghi, a new race of the fungus
from Palotina, PR. (Nakamura and Fernandes
1984).
Other Diseases
Other diseases occurring in Brazilian sorghum
fields which vary from year to year and from
region to region are included in Table 2. Grain
"weathering" is especially important in whiteendosperm
genotypes developed for human
food.
Selection for resistance to leaf blight (Exserohilwn
turcicum), zonate leaf spot (Gloeocercospora
sorghi), ladder spot (Cereospora fusimaculans),
and other diseases is conducted in the
National Sorghum Uniform Disease Nursery,
breeding trials, and the anthracnose and rust resistant
nurseries.
Studies of F1 F2 and F3 generations of crosses
between QL 3 (resistant) and susceptible genotypes
indicate that one dominant gene determines
resistance to Sugarcane mosaic virus
(Pinto 1984).
Sorghum Disease Research in Brazil
Disease resistance studies are undoubtedly essential
for continued efficient sorghum production
in Brazil. Development of resistant genotypes
is pursued in Brazil's sorghum breeding
program. Good hybrids recently developed by
the NMSRC, as well as those by private seed
companies, will be released soon. However, accurate
basic information about sorghum dis-
Table 5. Downy mildew incidence in 10 systematically infected sorghum genotypes in the 1983/84
National Forage Trial at Jaboticabal, Sao Paulo, Brazil.
Hybrid or Incidence
Cultivar variety Source (%)
H 1
AG 2001
AGROCERES 0.0
Sordan NK 77 H BRAZISUL 8.4
Contisilo H CONTIBRASIL 0.0
Brandes
V 2
EMBRAPA 0.0
CMSXS 615 V EMBRAPA 0.0
BR 601 H EMBRAPA 0.0
BR 601 H EMBRAPA 0.0
BR 603 H EMBRAPA 0.0
Sart V AGROCERES 4.7
IPA 7301158 V IPA 26.2
1. H = hybrid, 2. V = variety.
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