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Graminae
Synonyms
B. intermedia (R. Br.) A. Camus; Andropogon intermedius R.
Br.
Common names
Forest blue grass (Australia), lautoka grass (Fiji), Australian
blue-stem (United States).
Description
An erect to geniculately ascending branched perennial bunch
grass to about 1 m high; the culms, often rooting at the lower nodes, or,
rarely, producing stolons bearing pale green to purplish racemes, simple
or occasionally divided, arranged fairly densely about a central axis;
the sessile spikelets with short, fine, bent hairlike awns and lower glumes
conspicuously pitted with a single tiny hole like a pin-prick. Leaves strongly
aromatic when crushed, smelling and tasting like turpentine. Blade linear-lanceolate
and tapering gradually from the base to a fine hairlike point. Ligule inconspicuous,
short membranous and backed by sparse white hairs. Sheath glabrous and
slightly compressed. Culms round, slender, glabrous. Roots coarse, aromatic
(Rose-Innes, 1977).
Distribution
Africa, India to Australia and the Pacific, introduced to United
States.
Season of growth
Summer.
Drought tolerance
In Queensland, Australia, it occurs in the 700-800 mm rainfall
belt. It is fairly tolerant of drought conditions.
Soil requirements
It occurs mainly on heavy clay loam to clay soils often derived
from basalt in Queensland, and on heavier alluvial soils.
Ability to spread naturally
It will spread slowly by seed.
Land preparation for establishment
The land can be fully prepared for seeding or roughly prepared
for rooted slips.
Sowing methods
It is propagated by rooted slip in India.
Response to defoliation
It will stand heavy grazing up to one beast to 0.4 ha at Gayndah,
Queensland (700 mm rainfall with summer dominance) (Scateni, 1966).
Grazing management
Under experimental conditions at Gayndah, Queensland, a stocking
system of two weeks' grazing, six weeks' rest was adopted (Scateni, 1966).
In this environment it was shown that utilizing the native pasture (e.g.
Bothriochloa bladhii, Heteropogon contortus dominant) for summer and autumn
grazing and sown pasture (e. g. green panic and lucerne) for winter and
early summer grazing improved annual production (Scateni, 1966). Without
sown pasture, winter/spring grazing of 0.74, 1.24 or 2.47 animals per hectare
increased the basal cover of B. bladhii and H. contortus at the expense
of other species and improved the sward. Continuous summer grazing reduced
the percentage of B. bladhii at the expense of Dichanthium spp. Rotational
grazing resulted in an increase in B. bladhii.
Suitability for hay and
silage
It makes quite useful hay in Australia, the United Republic
of Tanzania and India. In the Kangra district in Punjab, B. bladhii top-
dressed with 28 kg N/ha in June and harvested in early September gave the
highest yields and the best quality hay (Gill, Rana & Negi, 1970).
Value as a standover or
deferred feed
It will provide useful roughage in the winter to be supplemented
with licks or concentrates.
Cultivars
No cultivars are registered but hybrids exist. A key has been
drawn up of the Bothriochloa intermedia complex by Faruqi (1969).
Diseases
It is often attacked by smut.
Main attributes
A palatable native grass which will tolerate drought conditions
and survive annual burning. It utilizes heavy soils well.
Main deficiencies
In Ghana it is unpalatable and an indicator of overgrazing
on the Accra plains. It also invades lawns in the coastal savannahs (Rose-Innes,
1977).
Frost tolerance
It survives seasonal frosts though the culms may be frosted.
It is not as tolerant as D. sericeum.
Palatability
It is a palatable grass in Queensland. In Ghana it is regarded
as unacceptable to livestock. At Richmond, New South Wales, dairy cattle
refused to eat it both in the young stage and later. It is somewhat aromatic.
Chemical analysis and
digestibility
Göhl (1975) gives figures in Table 15.8.
Natural habitat
Open forest on heavier soils.
Tolerance to flooding
It will tolerate short-term flooding.
Fertilizer requirements
It is not usually fertilized but will respond to nitrogen (Gill,
Rana & Negi, 1970).
Genetics and reproduction
2n=40, 50, 60, 80 (Fedorov, 1974).
Seed production and harvesting
In Queensland it seeds from midsummer (December) to late autumn.
No seed is harvested commercially.
Economics
A very useful native grass for beef cattle in central and southern
coastal Queensland, Australia.
Animal production
At Brian Pastures Research Station, Queensland, a pasture growing
on a heavy soil derived from basalt containing 43 percent B. bladhii, 17
percent Dichanthium sp., 17 percent Heteropogon contortus, 7 percent Chloris
divaricata, 4 percent Aristida sp. and 12 percent other species stocked
at 1.24 steers per hectare during the dry season (winter) from June to
November gave an average live-weight gain of 8.5 kg/ha over three years;
when supplemented with 0.75 kg/ha per day of cotton-seed meal (40 percent
crude protein) they gained 69.5 kg/ha. When grazed at 0.62 steers per hectare
during the wet season (December-May) in summer, steers gained 69.2 kg per
head (Addison, 1970). It was found useful in reseeding rangeland in the
southern United States.
Further reading
Scateni, 1966.
Value for erosion control
It is useful, but there are better grasses, e.g. B. insculpta,
suited to similar soils.
Tolerance to salinity
Not recorded.
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