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Graminae
Common names
Wool grass (Australia).
Description
It is a leafy, palatable, perennial tussock grass.
Distribution
Africa and Australia.
Season of growth
Summer.
Rainfall requirements
In South Africa it occurs in the 250-650 mm rainfall areas, most common in the 350 mm
area.
Drought tolerance
Excellent.
Soil requirements
Suited to the lateritic red earth soils and sandy soils with a pH range of 6-7. It will
not grow on heavy soils (Smith, personal communication).
Ability to spread naturally
Poor.
Land preparation for establishment
It requires some rough soil disturbance.
Sowing methods
Broadcast the seed.
Sowing depth and cover
It is surface sown and uncovered in western Queensland.
Sowing time and rate
Sow just before the wet season at 4 kg/ha.
Number of seeds per kg.
It varies considerably, with an average of about one million caryopses or 125 000
spikelets.
Response to defoliation
It can stand some grazing, but during severe grazing tillers can be pulled from the
ground.
Response to fire
Fire has little adverse effect on regrowth; it stimulates seed production in South
Africa and at Charleville, south-western Queensland.
Dry-matter and green-matter yields
On sandy, lateritic red earths at Charleville its yield over four years ranged from 1
555-3 980 kg/ha with a mean of 2 898 kg/ ha. From one harvest on heavy soil the yield was
1 330 kg/ha per year.
Seed yield
Varies enormously. From one hand harvest at Charleville the spikelet yield was 175
kg/ha (Smith, personal communication).
Palatability
It is very palatable and is sought by domestic animals and wildlife.
Chemical analysis and digestibility
At Charleville, material growing on sandy lateritic red earth contained 1.08 percent N
and 0.07 percent P. Göhl (1975) gives the analysis in Table 15.3.
Natural habitat
Widely distributed in Africa on sandy subtropical soils.
Tolerance to flooding
It will not tolerate flooding.
Fertilizer requirements
It responded to superphosphate at 250 kg/ha on a lateritic red earth soil at
Charleville, Queensland (lat. 26°4'S, altitude 980 m and rainfall 450 mm) (Silcock,
1976). In South Africa it responds to lime or superphosphate (at 140 kg/ha) on acid sandy
soils.
Genetics and reproduction
It is apomictic.
Seed production and harvesting
Severe chipping or burning prior to growing the seed crop increases seed production.
The seed-heads are clearly exserted well above the leaf growth, making mechanical
harvesting attractive. The seed on each head ripens fairly evenly and can all be harvested
at once. Emergence of seed-heads continues for about a month, with a peak seven days after
the first heads emerge, followed by a long tailing off period. Ripe seed can usually be
harvested 28-32 days after emergence of the seed-head (33-39 days after first head
emergence). With adequate water and fertilizer, seed can be harvested twice a year, once
in early summer and once in autumn.
Economics
It is a useful grazing grass in South Africa in low rainfall sandy areas, and shows
promise for sandy lateritic mulga (Acacia aneura) soils in south-western Queensland
(altitude 325 m; lat. 26°4'S and average annual rainfall 450 mm).
Further reading
Silcock, 1976.
Dormancy
There is some post-harvest dormancy for about nine months. Dehusking greatly improves
germination (Smith, personal communication).
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