Sorghum Diseases in India
Sorghum Diseases in India
Sorghum Diseases in India
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deficit and high temperatures are conducive to<br />
development of this disease. Late sow<strong>in</strong>gs (February)<br />
<strong>in</strong> double-cropp<strong>in</strong>g systems <strong>in</strong> central<br />
Brazil are also favorable to charcoal rot development.<br />
High <strong>in</strong>cidence of the disease has been<br />
observed <strong>in</strong> some of these areas.<br />
Because of the importance of sorghum <strong>in</strong> the<br />
northeastern and central regions, the National<br />
Maize and <strong>Sorghum</strong> Research Center (NMSRC)<br />
is beg<strong>in</strong>n<strong>in</strong>g a program to identify genotypes<br />
resistant to this disease, hop<strong>in</strong>g to <strong>in</strong>corporate<br />
this resistance <strong>in</strong>to elite cultivars. This approach<br />
is be<strong>in</strong>g used at the NMSRC-Experimental Station<br />
<strong>in</strong> northern M<strong>in</strong>as Gerais State, a semi-arid<br />
area.<br />
<strong>Sorghum</strong> downy mildew<br />
The sorghum downy mildew (Peronosclerospora<br />
sorghi) is commonly found <strong>in</strong> areas of the states<br />
of Rio Grande do Sul, Sao Paulo, Santa Catar<strong>in</strong>a,<br />
Parana, and M<strong>in</strong>as Gerais.<br />
Results from downy mildew trials (Table 5)<br />
have been obta<strong>in</strong>ed from the states of Sao Paulo<br />
and Rio Grande do SuL The reactions of some<br />
sorghum genotypes <strong>in</strong> Jaboticabal-Brandes<br />
show some to be susceptible to pathotype 4 of<br />
Peronosclerospora sorghi, a new race of the fungus<br />
from Palot<strong>in</strong>a, PR. (Nakamura and Fernandes<br />
1984).<br />
Other <strong>Diseases</strong><br />
Other diseases occurr<strong>in</strong>g <strong>in</strong> Brazilian sorghum<br />
fields which vary from year to year and from<br />
region to region are <strong>in</strong>cluded <strong>in</strong> Table 2. Gra<strong>in</strong><br />
"weather<strong>in</strong>g" is especially important <strong>in</strong> whiteendosperm<br />
genotypes developed for human<br />
food.<br />
Selection for resistance to leaf blight (Exserohilwn<br />
turcicum), zonate leaf spot (Gloeocercospora<br />
sorghi), ladder spot (Cereospora fusimaculans),<br />
and other diseases is conducted <strong>in</strong> the<br />
National <strong>Sorghum</strong> Uniform Disease Nursery,<br />
breed<strong>in</strong>g trials, and the anthracnose and rust resistant<br />
nurseries.<br />
Studies of F1 F2 and F3 generations of crosses<br />
between QL 3 (resistant) and susceptible genotypes<br />
<strong>in</strong>dicate that one dom<strong>in</strong>ant gene determ<strong>in</strong>es<br />
resistance to Sugarcane mosaic virus<br />
(P<strong>in</strong>to 1984).<br />
<strong>Sorghum</strong> Disease Research <strong>in</strong> Brazil<br />
Disease resistance studies are undoubtedly essential<br />
for cont<strong>in</strong>ued efficient sorghum production<br />
<strong>in</strong> Brazil. Development of resistant genotypes<br />
is pursued <strong>in</strong> Brazil's sorghum breed<strong>in</strong>g<br />
program. Good hybrids recently developed by<br />
the NMSRC, as well as those by private seed<br />
companies, will be released soon. However, accurate<br />
basic <strong>in</strong>formation about sorghum dis-<br />
Table 5. Downy mildew <strong>in</strong>cidence <strong>in</strong> 10 systematically <strong>in</strong>fected sorghum genotypes <strong>in</strong> the 1983/84<br />
National Forage Trial at Jaboticabal, Sao Paulo, Brazil.<br />
Hybrid or Incidence<br />
Cultivar variety Source (%)<br />
H 1<br />
AG 2001<br />
AGROCERES 0.0<br />
Sordan NK 77 H BRAZISUL 8.4<br />
Contisilo H CONTIBRASIL 0.0<br />
Brandes<br />
V 2<br />
EMBRAPA 0.0<br />
CMSXS 615 V EMBRAPA 0.0<br />
BR 601 H EMBRAPA 0.0<br />
BR 601 H EMBRAPA 0.0<br />
BR 603 H EMBRAPA 0.0<br />
Sart V AGROCERES 4.7<br />
IPA 7301158 V IPA 26.2<br />
1. H = hybrid, 2. V = variety.<br />
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