Sorghum Diseases in India

Sundaram (1977) reported control of ergot
with three sprays of ziram (0.2%); Anahosur
(1979) reported mancozeb (0.2%) gave better
control than ziram (0.2%). In subsequent years,
systemic fungicides like carboxin (Vitavax ® ) and
thiophanate (Topsin ® ) have shown some promise
at some locations.
Study of pollen management and effective
pollination using a spray of cytokinins, sucrose,
urea, and growth hormones is now underway.
Rust
Rust is destructive in the rainy and postrainy
seasons. Extensive screening of sorghum genotypes
by adopting the spreader row technique
(Sharma and Jain 1975; Sharma 1980) and four
spray inoculations with uredospores on alternate
days beginning on the 45th day of sowing
helped to create high disease pressure and identify
resistant genotypes. Disease scoring (1 = no
disease and 5 = more than 51% leaf area damaged)
showed SPV-247,1622 B, 2947 B, SB 401 B,
IS 3443, IS 3547, and IS 18758 were immune to
rust. Resistant genotypes were SPV-81,126, 245,
241, 312, 346, 351, 386, 459, 462, 472, 736, 775,
SPH-159, 176, 185, 187, 361, 364, MSH-51, 52,
DMS 1 B, M 9 B, M 12 B, MR 750, R 12 8, R 259,
RSR 9, IS 13442, E 36-1, IS 8185, IS 8607, and IS
7254. Most of these are of the tan plant type. The
level of resistance in the newly released genotypes,
compared to earlier genotypes, is very
high. Anahosur et al. (1981) reported on several
of the germplasm lines tested, and the majority
of the resistant lines were of the tan plant color.
Sorghum sown before the 3rd week of June
escaped from rust (Anahosur et al. 1982), whereas
in later sowings, made through October, the
disease was very high. Sorghum sown in November
and December showed less disease.
Gangadharan et al. (1976) reported effective
control of rust and leaf blight with zineb spray
(0.2%). Agarwal and Kotasthane (1973) reported
control of rust by seed dressing with oxycarboxin
(Plantvax ® ) followed by two sprays at
0.1%. Sharma (1980) reported ziram (0.2%), captan
(0.2%), and thiram (0.2%) as foliar sprays
gave effective control. Anahosur (1981) reported
that four sprays of mancozeb at 0.2% or 0.4% at
10-day intervals from the 35th day of sowing
gave significantly better control than ziram, captan,
and zineb.
With regard to inheritance of resistance
studies, Rana et al. (1976) reported that susceptibility
is dominant and resistance is governed
by three major genes. Indira et al. (1983) showed
that tan x tan crosses showed more resistance
than tan x purple or purple x purple crosses.
Tan parents transmitted resistance. Incomplete
dominance was seen in some tan x tan crosses in
which one parent was highly resistant. Our
study involved crosses 296 B(S) x IS 3547 (R), IS
3443(R) x QL (S), and 296 B(S) x QL 3 (S) and
indicated that resistance is dominant and governed
by one gene 3(R): 1(S) or two genes 15(R):
KS).
Leaf spots
Resistance evaluation against zonate leaf spot,
rough spot, leaf blight, gray leaf spot, and sooty
stripe showed the following genotypes to be resistant
at all AICMIP centres: SPV-81, 126, 312,
346, 351, 386, 462, 472, 544, 736, 775, APH-159,
176,185,187, 264, 361,362,411, M 6 B, M 10 B, M
12 B, DMS 1 B, SB 101 B, AKMS 3 B, ICS 4 B, CS
3541, SB 1085, R 250, R 390, R 1036, IS 3443, IS
8283, IS 8607, IS 3547, and IS 18758.
Anahosur (1986b) reported control of rust,
anthracnose, and zonate leaf spot by mancozeb
(0.2%) spray, whereas Sharma (1980) reported
control of leaf spot diseases by zineb (0.2%) or
ziram (0.2%).
Anahosur et al. (1980b) reported single-gene
resistance for gray leaf spot; susceptibility is
dominant.
Inheritance of resistance to zonate leaf spot in
crosses 296 B(S) x IS 3547(R), IS 3443(R) x QL
3(S), and 296 B(S) x QL 3(S) indicated that resistance
is a dominant trait and governed by three
genes 57(R): 7(S) or four genes 243(R): 13(S)
Red stripe
Usually sporadic in Maharashtra and Karnataka,
this virus disease appeared in a severe form in
Karnataka, Andhra Pradesh, Maharashtra, and
elsewhere in postrainy season, 1987.
Mali and Garud (1978) identified this virus as
a Johnsongrass strain of sugarcane mosaic virus
(SCMV). Several genotypes were tested; Indian
sorghums 73, 844, 952, 1040, 1518, 2301, 2522,
2601, 5169, 7499, 7998, 9227, and Gobwani were
51