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Graminae
Synonyms
L. scindicus Henr.; Elyonurus hirsutus (Forsk.) Boiss.
Common names
Sewan grass (Rajasthan, India), karera (Pakistan).
Description
A perennial, almost sub-woody at the base, with wiry, glaucous
stems, leaf-blade thin with a setaceous tip, racemes 10 cm long, densely
white villous, spikelets often three at each node, two sessile and one
pedicelled; sessile spikelets 6-9 mm long, the lower glume flat, hirsute
(Hutchinson & Dalziel, 1954). It has the maximum quantity of root material
in the top 0.03 m3 of soil.
Distribution
North Africa, Mali, Niger, Ethiopia, Iraq, southern Pakistan
and north-west India.
Rainfall requirements
It occurs in rainfalls below 250 mm a year. One of the dominant
species in arid zones with as low a rainfall as 12.5 mm in Rajasthan (Dabadghao
& Shankarnarayan, 1973).
Drought tolerance
Excellent.
Soil requirements
It grows best on alluvial soils or light brown sandy soils
with a pH of 8.5.
Sowing methods
At Jodhpur, Rajasthan, it is best sown in rows 30-90 cm apart
and weeded once (Chakravarty & Verma, 1972). In Thal, Pakistan, it
is germinated in earthen tubes about 30 cm long and then transplanted in
these tubes into the sand dunes at distances of 2 x 2, 3 x 2, or 3 x 3
m, with the top of the tube buried 10 cm in the sand. Protect the plants
from wind, using reed windbreaks, till well established (Khan, 1968).
Sowing time and rate
Transplant the tubes during rain or within 24 hours after rain
has fallen (Khan, 1968).
Seed treatment before
planting
Chakravarty and Bhati (1969) made 5 mm diameter pellets containing
one or two spikelets with a mixture of fine silt and cow dung. Germination
was not affected and the best stand came from two spikelet pellets stored
for four months.
Response to defoliation
At Jodhpur, Rajasthan, the highest dry-matter yields were obtained
by cutting at 30-day intervals to a height of 15 cm (Dabadghao, Roy &
Marwaha, 1973).
Dry-matter and green-matter
yields
2 700-10 500 kg fresh forage per hectare (Verma & Chakravarty,
1969) and dry-matter yields of 1 500 kg/ha (Chakravarty & Verma, 1972).
Well-established swards in western Rajasthan yielded 3 400 kg DM/ha (Ahuja,
1972).
Cultivars
Strain 318 is recommended by Prasad and Singh (1973) for cultivation
under dryland conditions in western Rajasthan.
Main attributes
Its drought resistance, its persistence on sand dunes and its
palatability.
Latitudinal limits
25-27°N.
Palatability
Good, one of the first grasses to disappear under the impact
of grazing.
Chemical analysis and
digestibility
No figures have been cited.
Natural habitat
Large bushy thickets in sandy deserts.
Fertilizer requirements
At Jodhpur, Rajasthan, application of 0-40 kg N + 20 kg PO:
+ 25 kg K2O/ha gave a yield of 4 860 kg/ha. Increasing nitrogen from 0-20
kg/ha increased yield from 3 500 to 5 810 kg/ha, but yields declined with
further increases in nitrogen rates (Bajpai & Jain, 1971).
Compatibility with other
grasses and legumes
Sowing with Vigna radiata, V. aconitifolia and Cyamopsis tetragonoloba
increased forage production by 1736 percent when rainfall was adequate,
in the first two years, but the legumes failed in the third year due to
drought (Daulay, Chakravarty & Bhati, 1972).
Genetics and reproduction
2n=56.
Economics
One of the most important arid zone grasses in north-west India.
Animal production
At Jodhpur, Rajasthan, carrying capacity was 4.2, 0.29 and
7.1 cattle units per hectare in 1968/69, 1969/70 and 1970/71 respectively,
with annual rainfalls of 178.8, 92.7 and 594.8 mm respectively (Gupta,
Saxena & Sharma, 1972).
Further reading
Chakravarty & Bhati, 1969; Chakravarty & Verma, 1972.4
Dormancy
Germination increases with storage up to four months.
Value for erosion control
It is useful stabilizing sand dunes in Iraq (Dougrameji &
Kaul, 1972).
Tolerance to salinity
It has a moderate tolerance to salinity.
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