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Graminae
Common names
Giant star grass (Nigeria), African star grass (Australia),
robust star grass.
Description
A large, robust, non-rhizomatous grass, deep-rooted. C. nlemfuensis
has two distinct varieties: var. nlemfuensis is somewhat finer and less
robust than var. robusta and resembles a very large C. dactylon except
that it has no rhizomes (Harlan, de Wet & Rawal, 1970). The inflorescence
has four to nine racemes, each 4-7 cm long. Var. robusta has seven to 12
racemes, each 6-13 cm long (Chippendall & Crook, 1976). Inflorescence
is one whorl (occasionally two), slender, green or pigmented.ô
Distribution
Var. nlemfuensis occurs mainly in Kenya, Uganda and Tanzania
with small outliers in Zaire and Ethiopia. Var. robusta has a similar base
with more representation in Ethiopia and eastern Zaire.
Soil requirements
It has a wide range of soil fertility and can mobilize and
recycle subsoil nutrients, especially calcium, to offset the increasing
acidity from high levels of sulphate of ammonia application (Mohamed Saleem,
Chheda & Crowder, 1975).
Sowing methods
It is propagated by rooted runners.
Response to defoliation
At Fashola Livestock Farm in Nigeria in the derived savannah
zone, C. nlemfuensis maintained a good stand and productivity when cut
fortnightly to a height of 2-3 cm (Ahlgren et al., 1959). Later, Chheda
and Mohamed Saleem (1972) showed that cultivar 1B.8 should be cut to a
height of 18 cm for optimum herbage production.
Dry-matter and green-matter
yields
Strickland (1976-77) recorded an average dry-matter production
of 1 600-2 000 kg DM/ha per month in summer and 4001 000 kg/ha per month
in winter from three accessions tested at Samford, Queensland (lat. 27°22'S,
1 050 mm rainfall, humid subtropical climate). In Nigeria the cultivar
1B.8 yielded 25 600 kg DM/ha over two harvests between 19 August and 26
October 1971 (Mohamed Saleem, Chheda & Crowder, 1975).à
Cultivars
Cultivar 1B.8 is a deep-rooted, non-rhizomatous variety and
lB.1 is a local variety in Nigeria, the local variety being consumed to
a greater extent than 1B.8 (Ademosun, 1973). Dry-matter intake values were
1.59, 1.36 and 1.51 kg per 100 kg body weight for the 1B.8 variety harvested
at four, seven and ten weeks of age and fed to goats. The corresponding
values for the local lB.1 variety were 2.09, 2.26 and 2.20 kg per 100 kg
body weight (Ademosun & Kolade, 1973).
Palatability
It is extremely palatable, especially when young.
Chemical analysis and
digestibility
Mohamed Saleem, Chheda and Crowder (1975) recorded a crude
protein of 7.8-8.0 percent, potassium content of 2.8 percent, a range in
phosphorus of 0.14 to 0.26 percent and of calcium from 0.16 to 0.31 percent,
the latter from an application of 2.5 t/ha of calcitic limestone. Ademosun
and Kolade (1973) compared two varieties of C. nlemfuensis var. robusta
(local or 1B.1 and var. nlemfuensis (1B.8) and found that when harvested
at six weeks both varieties yielded about 3 t/ha. Digestibility of dry
matter by goats was about 60 percent for both varieties.
Natural habitat
Disturbed areas in grassland, cattle paddocks, verges, on moist
alluvium.
Fertilizer requirements
Cultivar 1B.8 requires 0.22 percent phosphorus in herbage for
optimum production. It responds to heavy dressings of nitrogen.
Genetics and reproduction
Var. nlemfuensis is mostly a diploid, but a tetraploid race
has been encountered under cultivation and it crosses rather easily with
the diploid variety of C. dactylon. Var. robusta is a diploid with tetraploid
races under cultivation.
Seed production and harvesting
Strickland (1976-77) could only obtain a trace of seed from
three accessions tested at Samford, Queensland, in 1976-77.
Animal production
Owing to the confusion of nomenclature, figures are difficult
to verify. Plate 33 shows a herd of Boran cattle grazing what is probably
a C. nlemfuensis pasture in Kenya.
Further reading
Harlan, de Wet & Rawal, 1970; Strickland, 1976-77; Vicente-
Chandleretal., 1974.
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