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Graminae
Common names
Pangola grass (United States, Australia), pasto pangola (Peru),
pangola digit grass (Florida).
Description
A stoloniferous perennial which differs from D. pentzii mainly
in having the culms much branched, usually decumbent, and often rooting
from the lower nodes, the spikelets 2.5-3 mm long and quite glabrous, the
hairs on the upper glume and lower lemma being short, fine and inconspicuous.
D. decumbens is based on a plant from the Nelspruit district of the Transvaal.
Subsequently plants were referred to it that were cultivated in Pretoria
as the "Pangola River" strain of woolly finger grass (Chippendall, 1955).
Distribution
Originated in the Transvaal and now introduced into most tropical
countries.
Season of growth
Summer, with a growth period of up to seven months. It commences
growth in November and slows down in March in south-east Queensland.
Altitude range
In Hawaii, sea-level to 1 500 m.
Rainfall requirements
The mean rainfall is 900-1 975 mm (Russell & Webb, 1976).
In South Africa it grows well under the 625-750 mm summer dominant rainfall
on moist, fertile, well-drained soils but is better suited to rainfalls
of 1 000- 1 200 mm in coastal regions.
Drought tolerance
It will survive droughts fairly well if established, but will
not be productive.
Soil requirements
Pangola grass will grow over a wide range of soils on wet sands
or heavy clays and at low fertility levels. It will grow on poorer soil
than Paspalum dilatatum and Pennisetum clandestinum but in low fertility
soils is not very attractive to hungry stock.
Ability to spread naturally
Once pangola grass is established it spreads very rapidly by
stolons. It does not produce viable seeds.
Land preparation for establishment
An initial ploughing or other soil disturbance is required
so that sprigs can be incorporated in a loose soil.
Sowing methods
As pangola grass does not produce viable seed, propagation
is effected by sprigs or roots. For large areas, the quickest method is
to cut the vegetative plant material in a chaff-cutter or forage harvester
adjusted to provide plant pieces with a few nodes, broadcast this material
over the ploughed field and disc-harrow it in, or simply broadcast whole
runners and disc the area. Hand planting of roots about 1 m apart will
soon give a good cover. A small nursery area established ahead to provide
material for future enlarged planting is a sound approach.
Vigour of growth and growth
rhythm
Pangola grass grows vigorously when established.
Response to defoliation
Pangola grass tolerates heavy grazing. Extremely heavy grazing
is not harmful if the grass is allowed to grow again to a height of 30-45
cm afterwards (Bennett, 1973).
Grazing management
In Jamaica, Creek and Nestel (1965) found that pangola grass
grazed at 32-day intervals produced more dry matter and more liveweight
gain than when grazed at 40-day intervals. In the United States it is suggested
that it be grazed rotationally, allowing one week's rest during grazings
in midsummer and two to three weeks during the remainder of the growing
season (Bennett, 1973). In Colombia, Crowder, Michelin and Bastidas (1964)
recommended applying 84-114 kg N/ha after every cut at approximately two-
monthly intervals. Recovery rates for nitrogen were 50-75 percent.
Dry-matter and green-matter
yields
At Beerwah, south-east Queensland, under an annual summer dominant
rainfall or 1 075 mm, it produced a mean annual yield of 10 565 kg/ha per
year, fully fertilized (Evans, 1967a) and grows at the rate of 113 kg DM/ha
per day in summer, but only produces 2.25 kg DM/ha per day in winter (Evans
& Hacker, 1980). At South Johnstone in north Queensland (lat. 17°6'S,
altitude 580 m and rainfall 900 mm) 28 282 kg DM/ ha per year were obtained
from five cuttings from a pasture fertilized with 220 kg nitrogen, 22 kg
phosphorus and 55 kg potassium per hectare per year. It outyielded Panicum
maximum cv. Hamil and Brachiaria ruziziensis, but yielded less than Brachiaria
decumbens and B. mutica (Grof & Harding, 1970).
Suitability for hay and
silage
It cures rapidly in dry weather and makes excellent hay when
cut and cured before it gets too stemmy (Wheeler, 1950). It makes successful
silage in Florida.
Value as a standover or
deferred feed
When pangola grass matures, its feeding value declines and
standover feed, while providing roughage, is not very nutritious.
Toxicity
No toxicity has been recorded with this grass.
Cultivars
There is only one cultivar in Australia. In Florida, United
States, a slender-stemmed type known as 'Leesburg No. 5' has achieved some
success (Nester & Creek, 1962) and also cv. Transvala (Gaskins &
Sleper, 1974).À
Diseases
Pangola grass has been seriously attacked by a rust (Puccinia
oahuensis) in many areas causing agronomists to look for a replacement
grass among the Digitaria species (Evans, 1972). In Fiji it is affected
by a stunt virus which is also serious in Florida.
Main attributes
Its rapid cover, nutritious growth in the presence of nitrogen,
ability to establish on poor soils and withstand heavy stocking, and its
ability to combine with Lotononis bainesii.
Main deficiencies
Its lack of seed production and its susceptibility to rust,
its short growing season and its aggressiveness in relation to legumes
other than Lotononis bainesii.
Optimum temperature for
growth
The mean temperature where it grows is 19- 24°C (Russel
& Webb, 1976). In Hawaii it grows well between 25 and 40°C (Whitney
& Green, 1969). It grows actively above 26.5°C (Bryan & Sharp,
1965).À#S
Minimum temperature for
growth
The mean temperature of the coldest month in areas where it
normally grows is 7-15°C (Russell & Webb, 1976). Blue, Gammon and
Lundy (1961) suggested a 10°C minimum in Florida, and Bryan and Sharpe
(1965) about 15°C in south-east Queensland.JDP
Frost tolerance
It is susceptible to frosts, but generally recovers during
subsequent warm weather.
Latitudinal limits
The mean latitude is given as 21-30°N or S by Russell and
Webb (1976).
Response to light
It showed low tolerance to 50 percent light under coconuts
(Reynolds, 1978).
Ability to compete with
weeds
Pangola grass quickly suppresses weeds.
Pests
In Florida the yellow sugar-cane aphid (Sipha flava) is a major
pest (Bennett, 1973; Oakes, 1978). Another aphis (Schizaphis hypersiphata)
is also troublesome, and the crabgrass leaf beetle (Lemma rufotincta) less
damaging. The sting nematode may be serious. Minor pests are the lawn armyworm
(Spodoptera mauritia) and the sod webworm (Herpetogramma licarsisalis)
(Broadley & Rogers, 1978). Heavy aphis populations have caused severe
damage in the wet tropics (Teitzel & Middleton, 1979). Natural predators
such as ladybirds and hover flies exert some control.
Palatability
Excellent when the material is young and vigorous. It is usually
neglected in favour of other grasses when it becomes old and stemmy.
Response to photoperiod
It is a long-day plant and flowers in 14 hours of daylight
(Degras, Mathurin & Félicité, 1974).
Chemical analysis and
digestibility
The feeding value of pangola grass is high, but animal intake
near maturity can be limited by protein deficiency (Minson, 1967) unless
a late application of nitrogen fertilizer is given or it is grown with
a legume. Bryan and Sharpe (1965) reported a range of 3.9 to 11.6 percent
crude protein in the dry matter. In Costa Rica, analysis of material at
floral initiation revealed 11.81 percent crude protein, 30.2 percent crude
fibre, 36.3 percent nitrogen-free extract, 2.5 percent ether extract and
9.2 percent ash in 10 percent moisture material. Sulphur fertilization
of pangola grass through superphosphate increased the nutritive value of
pangola grass by overcoming a simple sulphur deficiency when diets contained
less than 0.17 percent sulphur (Rees & Minson, 1976).
Tolerance to flooding
It can withstand temporary, but not sustained, flooding.
Fertilizer requirements
Pangola grass responds markedly to nitrogen when matched with
adequate phosphorus, potash and trace elements. Normal applications of
nitrogen under irrigation are about 300 kg/ha per year. At Palmira Experiment
Station in the Cauca Valley, Colombia, dry-matter production increased
in linear fashion with each additional increment of nitrogen up to 224
kg/ha and in a curvilinear manner with higher applications. The critical
value for phosphorus in the dry matter at the immediate preflowering stage
is 0.16 percent. It can fix up to 65 kg N/ha per day (Weier, 1976). It
tolerates high aluminium (Spain, 1979).
Compatibility with other
grasses and legumes
Under suitable conditions for its own development, pangola
grass dominates all other species. It combines well with the legume Lotononis
bainesii (Bryan, 1961), as both stand heavy grazing. It can also grow with
Centrosema pubescens. In Florida, Kretschmer (1965, 1966) has grown it
satisfactorily with Stylosanthes humilis and Macroptilium atropurpureum
(siratro) where addition of nitrogenous fertilizer is low.
Genetics and reproduction
Pangola grass is highly male sterile because lagging chromosomes
produce unbalanced nuclei in the pollen, and female sterile because meiosis
fails to progress beyond the leptolene stage. Only one plant which has
produced seed has been observed (Sheth, Yu & Edwardson, 1956). It is
an aneuploid 2n= 17 (Hutton, 1970).
Animal production
With dressings of 448 kg and 896 kg N/ha on the moist Beerwah
(south-east Queensland) environment, pangola grass gave annual live- weight
gains in cattle of 1 220-1 340 kg/ha (Bryan & Evans, 1967). At Parada,
in north Queensland, a live-weight gain of 2 990 kg/ha/year was obtained
from grazing irrigated pangola grass fertilized with 672 kg N/ha per year
(Ebersohn & Lee, 1972). In the Ord River valley in northern Australia,
a maximum live-weight gain of 1 330 kg/ha a year was obtained from 11.5
weaner steers per hectare and there was no increase with increasing dressings
of nitrogen from 300 kg to 800 kg/ha per year (Blunt, 1978). A figure for
live-weight gains of beef cattle of about 1 300 kg/ha per year has also
been obtained in Florida (Motta, 1968), Puerto Rico (Caro-Costas, Vicente-Chandler
& Burleigh, 1961; Caro-Costas, Vicente-Chandler & Figarella, 1965),
Beerwah, Queensland (Evans, 1969) and Ayr, north Queensland (Deans et al.,
1976). In Brazil, Aronovich, Serpa and Ribeiro (1970) obtained an average
live-weight gain per hectare per year over four years of 349 kg with pangola
alone, 410 kg with a mixture of pangola grass and the legume Centrosema
pubescens and 531 kg/ha from a pangola grass pasture fertilized with 100
kg N/ha per year. At Turrialba, Costa Rica (605 m altitude, 2 688 mm rainfall)
a herd of 50 cows grazing a pangola grass pasture at intervals of 21 days
at 2.67 beasts per hectare produced 6 014 kg milk per hectare. The pasture
was fertilized with 100 kg urea per hectare, 150 kg potassium chloride
and 80 kg/ha triple superphosphate in April, followed by two additional
applications of 200 kg urea per hectare at intervals of four months (Blydenstein
et al., 1969). In the West Indies, pangola grass fertilized with 330 kg
N/ha produced an annual liveweight gain of 1 157 kg/ha, compared with unfertilized
pasture production of 357 kg/ha (Oakes, 1960).p#
Further reading
Aronovich, Serpa & Ribeiro, 1970; Bryan & Evans, 1967;
Bryan & Sharpe, 1965; Nestel & Creek, 1962.p
Value for erosion control
Wherever pangola grass can be successfully grown it will effectively
control erosion.
Tolerance to salinity
Fair.
Sowing time
Preferably during the rainy season so that the planting material
will root down quickly.
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