1. African Journal of Range & Forage Science 2010, 27(1): xx–xx
Printed in South Africa — All rights reserved
Copyright © NISC (Pty) Ltd
AFRICAN JOURNAL OF
RANGE & FORAGE SCIENCE
ISSN 1022–0119 EISSN 1727–9380
doi: 10.2989/10220111003703518
African Journal of Range & Forage Science is co-published by NISC (Pty) Ltd and Taylor & Francis
Research Note
New Sudangrass forage cultivars selected from the original population
(Sorghum bicolor ‘Garawi’, syn. S. sudanense)
Maarouf I Mohammed
Forage Research Program, Agricultural Research Corporation, PO Box 30, Khartoum North, Sudan
E-mail: ibrahimarof@yahoo.com
Received 19 August 2009, accepted 18 January 2010
The study represents the first efforts since 1909 to develop improved Sudangrass (Sorghum bicolor (L.) Moench, syn. S. sudanense
(Piper) Stapf) cultivars from the original genetic stock existing in the Sudan. Seven Sudangrass genotypes generated by individual
plant selection within the land race ‘Garawi’ were evaluated across seven environments in Khartoum State in 2003–2006. Selection
criteria were based on forage as well as seed-setting attributes. The objectives were to develop improved and reproducible
cultivars from the parent population Garawi. The results indicated that two genotypes, S.(32-2)A and S.51, were superior to the
parent population in forage yield, protein content, average stability of yield superiority and reproducibility. The increment in yield
was attained without significant delay in flowering duration. Both genotypes were recommended for forage production under the
traditional green chopping system. S.(32-2)A was officially released under the name Sudan-1 by the Variety Release Committee in
February 2009. The newly developed genotypes will contribute to widening the currently narrow genetic base of Sudangrass cultivars.
Seed of the newly developed genotypes can be provided in small amounts for research purposes upon written request to the author.
Keywords: forage sorghum, green chopping, Islang, neutral detergent fibre, Shambat
The currently available Sudangrass (Sorghum bicolor (L.)
Moench, syn. S. sudanense (Piper) Stapf) cultivars share
a very limited genetic background. Their genetic pool is
confined to the few grams of seeds introduced to the USA
from Sudan in 1909 by CV Piper (Maunder 1983). No
attempts have been made, since then, to generate new
lines from the land race ‘Garawi’, the mother population of
Sudangrass existing in the country of origin, Sudan. The
seeming variability among present Sudangrass cultivars
is largely attributable to crosses between ‘Redlan’ and
‘Greenleaf’ (Harvey 1977). Garawi represents a highly
mixed and genetically variable population with unpredict-
able performance for forage and seed attributes, a situation
that poses practical limitations on maintaining the required
features of a cultivar. Selection for high seed set in
Sudangrass has been rarely practiced (Kalton 1988). In 2001
a selection program within Garawi was initiated. This paper
highlights the salient features and findings of a research
program undertaken to develop improved and reproducible
forms of Sudangrass from its original source population.
Seven Sudangrass genotypes were developed by
individual plant selection during 2000–2003, namely S.10-1,
S.50, S.34, S.18, S.32-1, S.(32-2)A and S.51. Table 1 shows
the procedure used to generate these genotypes. The lines
S.10-1, S.50 and S.34 were characterised by high tillering
capacity and thin stems. The line S.(32-2)A was selected
for earliness and vigour in growth. The lines S.(32-2)A, S.18
and S.32-1 showed good tillering capacity and medium stem
thickness. The line S.51 showed poor tillering and thick
stems. It resembles grain sorghum in some morphological
features, such as the ear shape and seed colour.
The selected lines were tested against three checks
across seven environments in Khartoum State (an
unbalanced combination of years and locations). The
years extended from 2003 to 2006. The locations were
Kuku (15°39′ N, 32°36′ E), Islang (15°53′ N, 32°32′ E) and
Shambat (15°39′ N, 32°31′ E). Rainfall, temperature and
relative humidity prevailing in Khartoum State during the
years 2003 through 2006 and the long-term averages are
shown in Table 2. Generally, the climate is hot and dry. The
rainy season is short extending from July to September with
scant and fluctuating precipitation.
The checks comprised the traditional Sudangrass
land race Garawi, the traditional Abu Sab’in and Kambal
(recommended Abu Sab’in). Abu Sab’in, a dual grain/forage
variety, is the most widely grown forage sorghum cultivar in
the country. Kambal is an improved version of Abu Sab’in
released in 2004. Sowing dates covered most months of
the year. Sowing was done manually by placing the seeds
in furrows or holes opened on both sides of the ridges.
Nitrogen fertiliser was added at a rate of 55 kg N ha−1
. The
experimental plots were hand-weeded twice and irrigated
at intervals of 7–15 d. Chemical control of pests was not
practiced in any of the experiments.
The first cut was taken at the dough stage. The dry
matter yield (DMY) was estimated from a random sample

2. Mohammed2
of 0.5 kg taken from the harvested plot and air-dried to a
constant weight. The second cut was evaluated from the
experiments conducted at Shambat during the winter
seasons of 2003/04 and 2005/06. Days to flower, plant
height, stem diameter, tillering capacity, regrowth and
leaf:stem ratio were studied. Regrowth was evaluated 15 d
after cutting from three-metre-long rows randomly chosen
from each plot. The newly emerging shoots were harvested
and the average dry weight per metre row was determined.
Proximate analyses for neutral detergent fibre (NDF),
acid detergent fibre (ADF) and crude protein (CP) were
performed on a dry matter basis following the standard
procedure of the AOAC (1980).
A randomised complete block design was used.
Combined analysis of variance (ANOVA) was performed
using balanced data sets obtained for dry matter yield
(DMY) in two environments (Kuku and Islang, 2003/04) and
four environments (Kuku 2004, and Shambat 2005, 2005/06
and 2006). Stability analysis following Lin and Binns (1988)
was performed. The residual maximum likelihood (REML)
method (Patterson 1997) was used to combine the data
obtained for agronomic yield-related traits in different
environments. The statistical package GenStat version
9.1.0.174 (VSN International, Hemel Hempstead) was used
to perform ANOVA and REML analyses, whereas stability
analysis was carried out using AGROBASE Generation II®
version 14.4.1 (Agronomix Software, Winnipeg).
The performance of genotypes for DMY of the first cut is
shown in Tables 3 and 4. The genotypes differed signifi-
cantly (p < 0.01) in DMY in most of the separate environ-
ments and in the combined analysis as well. The interaction
of genotype with environment (Table 4) was highly signif-
icant, implying the need to investigate the stability of
genotypes across environments. The line S.(32-2)A
had the highest yield in most environments, averaging
5.36 t ha−1 over the two environments at Kuku and Islang
in 2003/04, and 5.16 t ha−1 across the four environments
at Kuku in 2004, and Shambat in 2005, 2005/06 and 2006.
Its DMY combined over Kuku and Islang 2003/04 (Table
3) exceeded that of the checks Kambal (3.09 t ha−1
) and
Activity Population size Selection criteria No. of selected genotypes
Source population (2001/02) Approximately 5 000 plants Individual plant selection for vigour
of growth, juiciness (green mid-rib),
leafiness, healthiness, plant height,
flowering time, tillering
220
Laboratory inspection (2002) 220 panicles Panicles with <75% seed set were
discarded
56
Replicated nursery (July 2002) 56 lines Forage and seed attributes, uniformity 21
PYT 1 (January 2003) 21 genotypes Forage yield and related traits, uniformity 10
PYT 2 (July 2003) 10 genotypes Forage yield and uniformity 7
Table 1: Procedure used to develop seven Sudangrass genotypes by selection within the land race cultivar Garawi at Shambat in
2000–2003). PYT = preliminary yield trial
Month
2003 2004 2005 2006 Long-term average
Temp.
RH
Rain
fall
Temp.
RH
Rain
fall
Temp.
RH
Rain
fall
Temp.
RH
Rain
fall
Temp. Rain
fall
Days
with
rainMin. Max. Min. Max. Min. Max. Min. Max. Min. Max.
Jan. 14.2 31.7 27 0.0 17.9 31.9 24.2 0.0 12.1 29.3 25 0.0 15.6 33.6 28 0.0 15.6 30.8 0.0 0.0
Feb. 15.5 33.5 16 0.0 18.1 32.6 20.4 0.0 17.4 37.0 24 0.0 16.1 35.6 19 0.0 17.0 33.0 0.0 0.0
Mar. 18.6 35.8 15 0.0 21.5 37.3 14.4 0.0 18.6 37.3 17 0.0 17.2 36.0 23 0.0 20.5 36.8 0.0 0.1
Apr. 21.3 40.6 16 0.0 27.0 41.4 17.7 trace 23.0 41.2 19 trace 19.2 38.6 19 0.0 23.6 40.1 0.4 0.1
May 25.8 41.9 21 26.2 27.9 43.3 20.0 20.0 22.9 40.7 23 12.3 25.7 41.2 25 35.5 27.1 41.9 4.0 0.9
Jun. 27.0 40.9 33 6.0 28.0 40.0 30.6 3.8 27.3 41.7 25 0.0 26.8 41.0 32 3.1 27.3 41.3 5.4 1.2
Jul. 25.2 37.3 49 41.1 28.1 40.8 30.4 25.0 24.5 34.3 41 3.0 27.5 40.2 39 0.1 25.9 38.4 46.3 4.8
Aug 25.3 35.8 58 74.0 27.1 38.5 45.9 45.0 26.2 37.1 53 56.3 27.0 36.6 56 0.9 25.3 37.3 75.2 4.8
Sep. 25.2 38.4 45 12.9 27.6 39.8 40.5 14.5 25.7 38.7 47 16.6 24.4 37.4 55 2.5 26.0 39.1 25.4 3.2
Oct. 23.9 39.9 31 3.4 23.9 39.5 36.0 2.1 23.8 39.8 29 trace 25.5 38.7 39 0.0 25.5 39.3 4.8 1.2
Nov. 20.3 36.1 29 0.0 19.9 36.1 32.0 0.0 19.6 35.6 25 0.0 19.9 33.3 27 0.0 21.0 35.2 0.7 0.0
Dec. 15.1 31.5 33 0.0 15.1 31.5 29.0 0.0 16.8 34.1 34 0.0 13.5 28.7 29 0.0 17.1 31.8 0.0 0.0
Table 2: Mean minimum and maximum temperature (Temp.; °C), relative humidity (RH; %) and total rainfall (mm) as recorded by the
Shambat Meteorological Observatory for the years 2003–2006 and the long-term averages (30 years)

3. African Journal of Range & Forage Science 2010, 27(1): xx–xx 3
Abu Sab’in (2.46 t ha−1
), whereas in the four environments
(Table 4) its DMY significantly exceeded that of the check
Garawi by 43%. On the other hand, the genotype S.51
showed the second-highest DMY among the selected
lines (4.98 t ha–1
) with a significant increase over Garawi
amounting to 38% (Table 4). Its average performance
over Kuku and Islang during 2003/04 (Table 3) was also
better than that of the checks Kambal and Abu Sab’in.
Cultivar superiority analysis (Table 4) revealed that the lines
S.(32-2)A and S.51 displayed the lowest G×E statistic
among the selected genotypes. They were both better than
the checks Garawi and Kambal in average stability of yield
superiority. In the second cut (Table 5) the line S.(32-2)
A significantly (p < 0.05) out-yielded the checks and other
selected lines in DMY averaging 1.63 and 2.54 t ha−1 during
the winter seasons in 2003/04 and 2005/06, respectively.
The respective DMY obtained by the check Garawi was
1.21 and 1.45 t ha−1
.
Significant (p < 0.001) differences were found between
genotypes for all agronomic yield-related traits (Table 6).
Differences in days to flower between the selected lines
S.(32-2)A, S.51, and the checks Garawi and Kambal were
not significant with respective flowering periods of 62.9,
63.6, 62.2 and 61.9 d (Table 6). Plants of these lines were
about 30 cm taller than the check Garawi. The lines S.50
and S.10-1 were the best in tillering capacity with 7.86 and
7.27 tillers per plant. The line S.50 also had the highest
regrowth ability and leaf:stem ratio, whereas S.51 was
among those with fewer tillers per plant. The line S.(32-2)A
showed medium value for regrowth, whereas S.51 showed
the lowest value among selected lines (Table 6).
The proximate analysis for quality traits (Table 6) showed
that the line S.(32-2)A had the highest CP content in the
whole material studied amounting to 7.88% followed by
S.51 (7.0%). The check Garawi and S.18 had the lowest CP
content and showed similar values (5.25%). The best NDF
Genotype
Location
Shambat Islang Kuku Mean combined (Kuku, Islang)1
S.50 3.51 4.17 3.75 3.92
S.10-1 3.22 4.44 4.76 4.63
S.18 2.88 3.74 2.93 3.26
S.(32-2)A 3.53 6.04 4.90 5.36
S.51 4.22 5.83 3.31 4.32
S.34 2.53 4.24 3.54 3.82
S.32-1 3.53 5.63 4.61 5.02
Kambal (check) 3.60 2.75 3.09
Abu Sab’in (check) 2.95 2.13 2.46
Garawi (check) 2.33
Mean 3.22 4.52 3.63 3.99
Significance ns * ** **
SE 0.438 0.495 0.356 0.289
LSD (0.5) – 1.614 1.068 0.843
CV (%) 19.3 15.5 17.0 16.2
1 Mean squares: environment (E) = 11.4106ns, genotype (G) = 4.4928**, G×E = 0.6669ns, residual = 0.4171
*,** Significant at 0.05 and 0.01 probability level, respectively; ns = non-significant at 0.05 probability level
Table 3: Dry matter yield (DMY; t ha−1) of seven Sudangrass genotypes and three check cultivars at Khartoum State in 2003/04
Genotype
Kuku Shambat
Mean combined1 G×E statistic
2004 2005 2005/06 2006
S.50 5.33 4.13 4.32 2.49 3.95 1.574
S.10-1 5.26 4.99 4.23 2.78 4.23 1.272
S.18 5.68 4.59 4.88 2.99 4.43 0.912
S.(32-2)A 6.57 5.00 5.50 4.03 5.16 0.214
S.51 6.69 4.52 5.53 3.73 4.98 0.379
Garawi (check) 4.04 3.97 3.64 2.91 3.60 2.256
Kambal (check) 5.10 5.28 3.98 5.30 4.90 0.618
Mean 5.52 4.64 4.58 3.46 4.46
Significance ** ns ** ** **
SE 0.303 0.312 0.253 0.282 0.145
LSD (0.5) 1.049 – 0.779 0.868 0.415
CV (%) 7.8 11.6 9.6 14.1 10.8
1 Mean squares: environment (E) = 10.5603**, genotypes (G) = 3.6464** , G×E = 1.0695**, residual = 0.2325
** Significant at 0.01 probability level, ns = non-significant at 0.05 probability level
Table 4: Dry matter yield (DMY; t ha−1) and cultivar superiority analysis (G×E statistic) of five Sudangrass genotypes and two checks grown
in different environments in Khartoum State

4. Mohammed4
percentages were shown by S.18 (44.6%) and S.50 (49.0%.).
These lines were better than S.(32-2)A and Garawi, which
showed similar NDF values of 60.5%. With regard to ADF,
S.(32-2)A was the best among the selected lines (36.7%)
but not better than Garawi (33.8%).
The results from experiments in different environments
demonstrate clearly that the lines S.(32-2)A and S.51 were
superior in forage yield than the traditional checks Garawi and
Abu Sab’in, with S.(32-2)A being particularly distinguished for
its improved second cut. Both genotypes were comparable or
sometimes better in dry matter yield than the recommended
cultivar Kambal. High forage yields in sorghum are usually
associated with prolonged flowering period (Ross et al. 1983,
Ferraris and Edwards 1986). In this study, increment in yield
was achieved without significant delay in flowering duration,
as both genotypes were comparable to the check Garawi in
days to flower. Therefore, S.(32-2)A and S.51 are well suited
to the locally prevailing green chopping system that favours
high forage yields produced over a relatively short period
of time. Cultivar superiority analysis indicated that both
genotypes showed the lowest G×E values; therefore they are
expected to keep their superiority in forage yield across a
wide range of environments.
Proximate analysis for quality traits indicated that
S.(32-2)A and S.51 were superior to Garawi in protein
content. Positive favorable association between yield and
protein, though of rare occurrence, has sometimes been
encountered (Vidal and Lazarte 1975, Muhammad 1990).
This favorable association was not evident for NDF and
ADF percentages. The NDF measures intake potential while
ADF predicts digestibility; however, the results suggest that
S.(32-2)A was not significantly inferior to Garawi in these
attributes. On the other hand, S.(32-2)A and S.51 were
juicier (having a green mid-rib) than the check Garawi (with
a white mid-rib). Juiciness is a good indicator for palatability,
especially under the prevailing green chopping system,
where forages are essentially offered as green matter.
Being a simply inherited character, juiciness was fixed in
the early stages of the breeding program by selecting for
the green mid-rib colour.
As pointed out earlier, the present Garawi population
is highly mixed and genetically variable. This is due to
the high out-crossing rate known to occur in Sudangrass
(Pedersen et al. 1998). According to de Wet et al. (1970),
S. sudanense is among four species developed by natural
hybridisation between cultivated forms and members of the
weedy series Spontanea. Such a high level of heteroge-
neity poses practical limitations on maintaining the required
features of a cultivar. Moreover, low seed set is one of the
negative contributions of the weedy types to the genetic
pool of Sudangrass populations. In this study, uniformity
and high seed set were some of the selection criteria that
have been considered in developing S.(32-2)A and S.51.
Therefore, in addition to their improved agronomic and
quality performance, S.(32-2)A and S.51 have improved
reproducibility over the traditional Garawi.
The newly developed genotypes may contribute to
diversification of the already depleted genetic variability
of Sudangrass populations. The lines S.(32-2)A and S.51
Genotype
DMY (t ha–1)
2003/04 2005/06
S. 50 1.19 1.48
S.10-1 1.36 1.59
S.18 0.99 1.55
S.(32-2)A 1.63 2.54
S.51 1.46 1.48
S.34 1.29
S.32-1 1.35
Garawi (check) 1.21 1.45
Kambal (check) 1.24
Abu Sab’in (check) 0.68
Mean 1.31 1.50
Significance * **
SE 0.078 0.142
LSD (0.05) 0.260 0.474
CV (%) 8.4 13.4
*,** Significant at 0.05 and 0.01 probability level, respectively
Table 5: Dry matter yield (DMY) of the second cut obtained by
different Sudangrass genotypes and the check cultivars grown at
Shambat
Genotype
Days
to flower
Plant
height (cm)
No. of tillers
per plant
Regrowth
(g m–1
row)
Stem
diameter (cm)
Leaf:stem
ratio (%)
Proximate analysis
CP (%) NDF (%) ADF (%)
S.50 66.7
71.3
65.0
62.9
63.6
63.2
60.5
62.2
61.9
57.7
179
177
193
214
202
207
189
173
194
182
7.86
7.27
5.73
5.08
3.02
6.41
3.29
4.35
525
232
206
302
110
332
322
141
121
0.75
0.76
0.91
0.92
0.96
0.92
0.97
0.87
1.13
1.22
42.0
36.7
37.3
37.6
33.4
33.9
35.5
37.6
33.7
6.13
6.57
5.25
7.88
7.00
5.25
49.0
44.6
60.6
60.5
39.7
53.7
36.7
33.8
S.10-1
S.18
S.(32-2)A
S.51
S.34
S.32-1
Garawi (check)
Kambal (check)
Abu Sab’in (check)
Mean 63.5 191 5.38 255 0.94 36.4 6.35 53.7 41.0
χ2 probability <0.001 <0.001 <0.001 <0.001 <0.001 <0.001
SED 1.744 10.08 0.6432 63.82 0.09048 1.295 0.757 4.66 4.15
Table 6: Yield-related traits and proximate analysis of some Sudangrass genotypes and check cultivars grown in Khartoum State in
2003–2006). ADF = acid detergent fibre, CP = crude protein, NDF = neutral detergent fibre

5. African Journal of Range & Forage Science 2010, 27(1): xx–xx 5
were improved over their original population (Garawi) in
terms of forage yield, uniformity and seed-setting ability.
The former line was officially released by the Variety
Release Committee in February 2009. In addition to their
improved per se performance, they may also serve as
potential parents in hybrid combinations. Seed of the
newly developed Sudangrass genotypes is maintained by
the Forage and Range Research Program, Agricultural
Research Corporation (ARC), Shambat Research Station.
Limited amounts of seed may be provided for research
purposes upon a written request to the author.
Acknowledgements — The author is grateful to MAM Khair, national
coordinator for forage and range research, ARC, Wad Medani,
Sudan, and AE Elasha, Editor-in-chief of the Sudan Journal of
Agricultural Research, ARC, Wad Medani, Sudan, for reviewing the
manuscript and for their valuable comments and suggestions.
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