Digitaria decumbens Stent
Pangola grass, Slenderstem, Transvala digitgrass
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
- Biotic Factors
All forms of this grass are excellent pasture grasses, as it remains green and
grows throughout alternate wet-dry seasons in the dry Tropics. Forage has
outstanding palatability for grazing and harvested forage. Competitiveness of
this grass has been used in weed control, in Florida and elsewhere where
rotated with vegetable crops. In Hawaii it is used for slope conservation.
No data available.
Per 100 g, the forage is reported to contain, on basis, 10.8 g protein, 2.0 g
fat, 74.4 g total carbohydrate, 29.8 g fiber, 9.8 g ash, 450 mg Ca. and 350 mg
P. According to Gohl (1981), the mean crude protein zero-moisture content of
610 samples of pangola grass was as follows: when fertilized with nitrogen,
13.2%; with rotational grazing, 10.5%; with constant grazing, 5.6%; and
Source: Gohl, 1981.
Perennial grass, stoloniferous with numerous decumbent stems that root at nodes
which touch the ground; culms leafy and only slightly tufted; leaves upright,
up to 23.5 cm long; sheaths nearly glabrous; inflorescence many-branched, with
many florets, less than .001% producing viable seed; racemes spreading at
maturity; spikelets 2.7-3 mm long, glabrous or sparingly silky on the
internerves; seed stalks 90 cm or more in height (Reed, 1976).
Reported from the African Center of Diversity, pangola, or cvs thereof, is
reported to tolerate aluminum, drought, grazing, heavy soil, insects, low pH,
poor soil, salt, sand, shade, slope, trampling, ultraviolet, weeds, and wind.
Does not tolerate prolonged waterlogging, alkaline conditions, or copper
deficiency. Possibilities of improving pangola grass is by selection of
vegetative variation among plants. Most plants now planted have come from a
few original sprigs and few important variants have been found. It is believed
that pangola grass was produced by hybridization of distantly related species;
thus accounting for its sterility. A few variations more recently have shown
some promise. 'Pangola grass' was released in Florida in 1945; 'Slenderstem
digitgrass' was released in Florida in 1969 and has been planted in several
countries. Recently, 'Transvaal digitgrass' a good forage grass resistant to
Sting nematode (Belonolaimus longicaudatus) and to Pangola Stunt Virus
(PSV), has been introduced to Hawaii, Guam, West Indies, and northern South
America. (2n = 30, 27 in 'transvala') (Reed, 1976)
Native to South Africa, Transvaal, and similar locatilities. Introduced in
United States in 1935 from South Africa. Now, widely distributed and
well-established in tropical and subtropical pasture areas, Along Gulf Coast of
Mexico, over 400,000 ha are under cultivation (Reed, 1976).
Ranging from Warm Temperate Moist (without frost) to Wet through Tropical Dry
to Wet Forest Life Zones, pangola grass is reported to tolerate annual
precipitation of 6.6 to 41.0 dm (mean of 20 cases = 14.1), annual temperature
of 15.9 to 27.8°C (mean of 20 cases = 22.5), and pH of 4.3 to 8.5 (mean of
17 cases = 6.3) (Duke, 1978, 1979; Reed, 1976). Pangola grass tolerates a wide
range of soil moisture, pH, and soil fertility. Thrives best when grown in
full sun or well-drained moist soils, but good growth can be obtained on soils
ranging from sands to heavy clays. It will tolerate light shade and salt spray
when planted in coconut groves on beaches. Inadequate rainfall is main factor
limiting production range and yield; requires above 63 cm/annum rainfall.
Transvala, Pangola, and Slenderstem digitgrasses are all subject to winterkill
in Florida (Reed, 1976).
Since Pangola grass and its variations produce almost no seed, it is nearly
entirely propagated by stems and crowns, adding to the cost of establishment.
Under most conditions, the returns derived from a well-established stand far
outweigh the cost of establishment. The grass is easy to establish throughout
the year, the probability of survival increased in the wet season. Growth rate
and production are reduced during drought, still it is relatively drought
tolerant. Mechanized plantings are made on large flat areas, free of boulders.
Hand planting is recommended for small areas, stony land, and steep slopes.
Pangola grass can be grown pure or in mixtures with tropical legumes, as
Centrosema pubescens or Desmodium leiocarpum, in Ghana. Although
it is superior to some other warm-season sodgrasses in its competitiveness
against wiry and erect forms of herbaceous and woody weeds, it can also be
detrimental to herbaceous legumes. Pangola grass shows significant increases
in forage yield as result of single annual application of fertilizer, and gives
maximum forage production with split applications. In Florida a fertilizer
program similar to the following is suggested: a 10-10-10 fertilizer at rate of
560 kg/ha between Oct. 1-Mar. 31; 12-6-6, 450 kg/ha between Apr. 1-May 15;
Ammonium sulfate, 170 kg/ha between May 16-Aug. 15; and 12-6-6, 450 kg/ha
between Aug. 16-Sept. 30. Green matter yields are increased 50% by addition of
830 kg/ha of 12-6-8 fertilizer, applied in a single annual application as
top-dressing. Ammonium sulfate is the most common source of N used on pasture
grasses. Pangola grass can be easily eradicated by soil sterilants or
non-selective herbicides; or during the dry season by following proper cultural
practices. Swine relish the roots, but it is not advisable to use them to
eradicate the grass because of the damage they do to soil tilth and texture.
Selective grazing causes pangola grass to decrease in a mixed pasture.
Long-established grass survives better when the heavy growth has been removed.
Pangola grass can be established and makes vigorous growth on sandy soils with
pH 4.2-4.5, if it receives a complete fertilizer and necessary minor elements.
Liming is recommended, with initial treatment of 2.5 T/ha on newly cleared land
with reliming at same rate set at 4-year intervals. Crop also has high ability
to withstand heavy trampling by livestock and rapid recovery from overgrazing
Higher annual production of forage is obtained when harvested at 6-week
intervals rather than 3-week intervals. Delayed grazing may result in higher
production but reduced quality and protein content. Rotational grazing is
advantageous to obtain highest yields of quality forage and to maintain
adequate stands. When grass is grazed to 10-15 cm, cattle should be moved to a
new stand. In Ghana, 5 harvests are made between Mar. 12 and Nov. 16, at
2-month intervals (Reed, 1976).
DM yields can be affected by slope. In Taiwan, pangola grass on slopes
10-14deg. bulldozed across the slope yielded 19.2 MT DM/ha, compared to 15.0 MT
bulldozed down the slope. On slopes of 14-18°, the yields were 14.9 MT and
9.5 MT/ha. On steeper slopes, yields were 6.3-8.5 MT/ha. Properly fertilized
pangola pastures have yielded more than 2.5 MT beef/ha in the West Indies
(Hsieh, 1979). Grown in pure stand, pangola grass yields green matter, 16,645
kg/ha, based on 5 cuttings per year, or 3,329 kg/ha per cuttings, the first and
second cuttings highest. In mixed stands with Centrosema, 27,853 kg/ha,
with average 5,571 kg/ha per cutting; and mixed with Desmodium, 20,041
kg/ha, average 4,508 kg/ha. Yields of 'Transvala', fresh, average 9,982 kg/ha;
'Slenderstem', 6,957 kg/ha; and over a 2-year period, dry matter yields
for'Transvala', 55,000 kg/ha; for 'Pangola', 47,000 kg/ha. Invariably, dry
matter yields declined from first to fourth harvest but then rose in fifth,
suggesting seasonal fluctuation. Most fall-harvested hay is medium to low in
protein content, but an application of N 3 weeks before mowing gives increased
digestible crude protein and consumption rate of the hay. Its productivity and
feeding value make this versatile grass an important forage crop in its area of
adaptation, mainly in dry Tropics at lower elevations. Grown in Florida and
California, West Indies, northern South America, Hawaii, Guam, Mexico, and West
Africa (Ghana). Adapted to other such areas (Reed, 1976).
According to the phytomass files, annual productivity ranges from 0 to 36 MT/ha
(28 in Australia, 7 in Brazil, 2-3 in Colombia, 4-31 in Cuba, 7-12 in Guyana,
18 in Hawaii, 7 in Jamaica, 18-36 in Puerto Rico, 6 in Sarawak, 6-23 in Taiwan,
and 0.6 in Venezuela) (Duke, 1981b). Almedia (1981) tabulates data from
Cardenas, Tabaso, Mexico, indicating a net annual productivity >43 MT/ha/yr,
a gross >51. Daily productivity was tabulated at 11.8 g/m2.
Other reported high yields in Digitaria include D. eriantha,
22-45 MT/ha; D. milanjiana, 4-34; D. pentzii, 4-31; D.
setivalva, 2-9, D. smutsii, 27-33; D. swazilandensis, 23-35;
and D. valida, 5-19. No doubt crab grass could be made into an energy
producer instead of an energy consumer, as one of the World's Worst Weeds.
Pangola grass is attacked by the following fungi: Mycosphaerella tassina,
Piricularia grisea, and Rhizoctonia solani. Pangola stunt virus is
a serious disease, transmitted by a delphacid vector, Sogata cifera;
however, 'Transvala' is resistant to it. Plants also affected by Potato Virus
Y. Nematodes isolated from Pangola grass include: Belonolaimus
longicaudatus to which 'Transvala' is resistant, Dolichodorum
nigeriensis, Helicotylenchus pseudorobustus, Meloidogyne incognita,
Peltamigratus nigeriensis, Rotylenchulus reniformis, and Scutellonema
clathricaudatum. Pangola is recommended as a rotation crop on sandy soils
infested with cotton root-knot nematode. Insect pests causing severe damage to
Pangola grass are Fall armyworm (Spodoptera frugiperda) and Grassworm
(Mocis latipes). Yellow sugarcane aphid (Sipha flava), a major
pest in Florida, Spittle-bug (Prosapia bicincta), Rhodesgrass scale
(Antonia graminis), mole crickets and leafhoppers. Local agriculture
agents may have suggestions for control.
|As % of dry matter |
|Fresh, early bloom, Trinidad||28.6||8.2||33.3||6.9||2.0||49.6 |
|Fresh, dough stage, Trinidad||39.3||6.8||29.5||7.8||2.1||53.8 |
|Fresh, pasture, 10 days' regrowth after grazing, Trinidad||14.8||14.9||31.0||11.4||
|Fresh, pasture, 15 days' regrowth after grazing, Trinidad ||20.3|| 13.7|| 29.6 ||10.9||
|Fresh, pasture, 21 days' regrowth after grazing, Trinidad ||21.4 ||9.2 ||35.3|| 12.2||
2.3|| 41.0 |
|Fresh, pasture, 42 days' regrowth after grazing, Trinidad || 21.1|| 4.8|| 36.3 ||6.9||
1.0 ||51.0 |
|Hay, 35 days, Venezuela|| ||6.9 ||34.7 ||9.8 ||1.8 ||46.8 |
|Hay, 45 days, Venezuela|| 7.5|| 33.1|| 9.8 ||2.3 ||47.3 |
|Hay, 62 days. Venezuela|| ||5.8|| 29.6|| 9.1 ||2.3|| 53.2 |
|Standing hay, Trinidad ||71.8 ||3.2 ||33.5 ||5.9 ||1.3 ||56.1 |
|Silage, Trinidad ||27.2||6.9||29.9 ||16.2 ||2.0|| 45.0 |
Complete list of references for Duke, Handbook of Energy Crops
- Almedia M.R. 1981. Productividad primaria de tres praderas de especies
tropicales: Para (Brachiaria mutica), grama amarga (Paspalum
conjugatum), y pangola (Digitaria decumbens). Bol. Soc. Bot. Mex.
- Duke, J.A. 1978. The quest for tolerant germplasm. p. 1-61. In: ASA Special
Symposium 32, Crop tolerance to suboptimal land conditions. Am. Soc. Agron.
- Duke, J.A. 1979. Ecosystematic data on economic plants. Quart. J. Crude Drug
- Duke, J.A. 1981b. The gene revolution. Paper 1. p. 89-150. In: Office of
Technology Assessment, Background papers for innovative biological technologies
for lesser developed countries. USGPO. Washington.
- Gohl, B. 1981. Tropical feeds. Feed information summaries and nutritive values.
FAO Animal Production and Health Series 12. FAO, Rome.
- Hsieh, C.H. 1979. Observations on the effect by bulldozer clearing of sloping
land for pasture establishment. J. Taiwan Livestock Res. Institute
- Reed, C.F. 1976. Information summaries on 1000 economic plants. Typescripts
submitted to the USDA.
last update July 9, 1996