Pennisetum purpureum K. Schumach.
Elephantgrass, Napier grass, Uganda grass
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
- Biotic Factors
This is one of the highest yielding tropical forage grasses. In Malawi it is
considered as a cut-and-carry forage for stall feeder systems. In areas where
adapted, grown for green feed, silage and rotational grazing. Its stemmy
nature limits its usefulness for grazing purposes, as animals selectively eat
leafy portions and leave stems behind. Said to equal bamboo for paper making.
It has been used to suppress Imperata cylindrica in the Philippines. Venkatesh
and Shetty (1978) found the growth rate of grasscarp fed hybrid Napier grass
was three times the rate of those fed Hydrilla verticillata and five
times Ceratophyllum demersum. Reported as a weed in nine crops in 25
countries (Holm et al, 1977).
In Spanish Guinea the leaf and stalk infusion is used as a duiretic in anuria
or oliguria. In Central Africa, used as a source of a medicinal salt (Watt and
Per 100 g, the hay is reported to contain 10.9 g H2O, 8.2 g protein, 1.8 g fat,
68.6 g total carbohydrate, 34.0 g fiber and 20.5 g ash. Silage contains 5.8 g
protein, 4.9 g fat, 73.4 g total carbohydrate, and 15.9 g ash. Fresh grass
contains 77.8 g water, 1.0 g protein, 0.5 g fat, 17.6 g total carbohydrate, 3.1
g ash, 0.12% Ca and 0.07% P. Green fodder contains calcium, 0.12; phosphorus,
0.07; potassium, 0.80; sodium, 0.10; magnesium, 0.06; iron, 0.021; sulphur,
0.03; and silicon, 0.57%. It is a good source of carotene (182221 mg/g) and
tocopherol (195-260 mg/g). Napier grass meal was as effective in maintaining
the growth of the birds as lucern meal. A nutritious silage, highly palatable
to animals, can be prepared after adding molasses (2%) and salt (0.8%)
(C.S.I.R., 1948-1976). Gutierrez and de Faria (1979) determined that the main
free sugars were glucose, sucrose, and fructose, with fructose content always
higher than glucose.
Seiler et al. (1979) report fatal nitrate poisonings in cattle whose diet
consisted solely of Napier grass. Levels of nitrate averaged 28.3 mg/g with
some samples as high as 44 mg which levels in the same species from non-toxic
areas was 3.9 mg/g.
Tall, tufted, rhizomatous perennial, very coarse and robust, in dense clumps;
culms 27 m tall; leaves large, 3090 cm long, up to 3 cm broad, elongate;
flat; panicles dense, usually more than 15 cm long, stiff, tawny or purplish;
fascicles sessile, the sparsely plumose bristles exceeding the 2 or 3 unequally
pedicelled spikelets; grain permanently enclosed in the lemma and palea;
spikelets not wore than 7 mm long. 4x = 28; 8x = 56; 2n = 27. Seeds
Many cultivars of elephantgrass have been developed in tropical countries, as
in Brazil (16 vars.), Malawi, Cameroons, Congo and Gold Coast. "Merkergrass"
has a more blue green color. Merker can bloom 60 days after planting and
reseeds itself occasionally. Bogden mentions Capricorn, Cubano, Domira, Ghana,
Gold Coast, Merker, Merkeron, Mineiro, Napier, Pungwe, Uganda, and Urukwanu as
noteworthy cultivars. In Brazil, e.g. 'Mineiro' yielded 21.4 and 30.0 MT/ha
in two rainy seasons and 3.3 and 6.0 MT/ha in two dry seasons during two years,
outyielding the other 11 cultivars studied. Reported from the African Center
of Diversity, elephantgrass or cvs thereof is reported to tolerate drought,
fire, frost, fungi, high pH, laterites, low pH, monsoon, savanna, sewage
sludge, virus, weeds, and waterlogging (Duke, 1978). Pusa Giant Napier, an
Indian cv, is said to be more nutritious, succulent, palatable and responsive
to N than Napier Grass. It is said to have yielded 279 MT fodder/ha, cf 135
for Napier (C.S.I.R., 19481976). (2n = 28, 27, 56)
Native to tropical Africa. Introduced to South America, Puerto Rico,
Philippine Islands, Hawaii and southern United States.
Requires a rich soil for best growth. It does not tolerate much frost, so
culture is limited to warmest parts of mainland United States and Hawaii. The
herbage is killed by frost but soil must be frozen to kill the rhizome.
Thriving on poorly drained soils to dry sandy soils, it grows best in rich
well-drained soils. In Uganda, napier grasslands are considered the fire
subclimax to evergreen forest. Ranging from Warm Temperate Dry to Wet through
Tropical Dry to Wet Forest Life Zones, elephantgrass is reported to tolerate
annual precipitation of 2.0 to 40.0 dm (mean of 34 cases = 16.5) annual
temperature of 13.6 to 27.3°C (mean of 34 cases = 23.0) and pH of 4.5 to 8.2
(mean of 28 cases = 6.2). (Duke, 1978, 1979)
Usually propagated vegetatively; if grown from seed, it is started in a nursery
and transplanted. To control weeds at the first stages of establishment,
inter-row cultivation and herbicides can be used; in Cuba 6 kg atrazine/ha was
a more effective herbicide (Bogdan, 1977). It is grown in rows and cultivated
for highest yields. Fertilizer of 100150 kg/ha of N after each harvest gives
best uniform production, with total of 900 kg/ha of N for six harvests.
Potential carrying capacity of Napier grass is very high with application of 50
kg/ha of N after each harvest, thus maintaining about 27 head/ha.
Feeding whole or chopped at 45 day regrowth had no effect on digestibility of
all nutrients, but wilting increased the digestibility of dry matter, crude
protein and crude fiber; also digestibility of N-free extract and gross energy
were significantly higher for wilted than for fresh grass. These factors were
increased in 60 day regrowth.
In some of the referenced studies, dry matter forage yields range from 27.3 to
37.1 MT/ha in regions with over 125 cm rainfall year. Yield of dry matter
increased with advancing maturity, with average yields of 4.85 and 7.27 MT/ha
at 45 and 60 day regrowth intervals, respectively. Average yield of
unfertilized grass during the wet season ranges from 3.25.3 MT/ha, and for dry
season, from 2.44.4 MT/ha, with range of age of 4263 days. Yields of crude
protein range from 403.55 to 487.09 kg/ha for 45 and 60 days cutting intervals,
respectively. Yields are higher under longer than shorter photoperiods.
Summarizing several previous studies, Bogdan (1977) concludes that yields in
farm practice are more likely to be 210 MT/DM/ha/yr for low or no fertilizers
and 630 for well fertilized farms, not the illustrious 85 MT one finds under
According to the phytomass files (Duke, 1981b), annual productivity ranges from
2 to 85 MT/ha. Miyagi (1980) obtained annual yields as high as 500 MT WM/ha
and 70 MT DM, spacing the plants 50 x 50 cm, outdoing the high reported by
Bogdan (1977) at 310 MT WM. Some of the higher DM yields reported are 19 MT/ha
in Australia, 66 in Brazil, 58 in Costa Rica, 85 in El Salvador, 48 in Kenya,
14 in Malawi, 64 in Pakistan, 84 in Puerto Rico, 76 in Thailand, and 30 in
Uganda (Duke, 1981b). Stems of elephant grass are primarily lignocellulose
with virtually no juice sugars. High N is required for high biomass yields.
Experimental yields in Queensland, Australia, have attained 70 MT DM/ha/yr of
which 50 are stem. Expected farm yields might be 5055 MT DM, while the best
sugarcane yields are about 50 in north Queensland. Stewart et al. (1979)
identified no other advantage of elephant grass over sugarcane as an energy
crop. Pennisetum americanum is reported to yield 122 MT/ha/yr, P.
clandestinum 225, P. pedicellatum 38, P. polystachyion
310 (Duke, 1981b).
Following fungi have been reported on Elephantgrass: Aegerita penniseti,
Apiospora camptospora, Armillaria mellea, Beniowskia pennisetae, B.
sphaeroidea, Cercospora fusimaculans, C. penniseti, C. sorghii, Didymosphaeria
panici, Gloeocerospora sorghii, Helminthosporium ocellum, H. sacchari,
Lacellinopsis spiralis, Leptosphaeria penniseti, L. penniseticola, Myrothecium
gramineum, M. striatisporum, Nigrospora oryzae, Periconia sacchari, Phyllachora
penniseti, Piricularia grisea, Puccinia penniceti, Sclerospora graminicola,
Septoria penniseti and Stagonospora penniseti. It is also attacked
by the bacterium, Pectobacterium carotovorum, and several diseases as
Pseudo-Fiji Disease, Chlorotic streak, a disease of sugarcane, and leaf mottle
virus. Elephantgrass is also attacked by the following nematodes:
Aphelenchus avenae, Meloidogyne incognita acrita, M. javanica and
Pratylenchus brachyurus.(Golden, p.c., 1984) Pennisetum purpureum is
an alternate host of Cassytha filiformis L., Helminthosporium
sacchari, Leptosphaeria sacchari, Meloidogyne sp. and Phyllosticta
sp. (Holm et al, 1977).
Complete list of references for Duke, Handbook of Energy Crops
- Bogdan, A.V. 1977. Tropical pasture and fodder plants. Longman, London.
- C.S.I.R. (Council of Scientific and Industrial Research). 19481976. The wealth
of India. 11 vols. New Delhi.
- Duke, J.A. 1978. The quest for tolerant germplasm. p. 161. 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. 89150. In: Office of
Technology Assessment, Background papers for innovative biological technologies
for lesser developed countries. USGPO. Washington.
- Gutierrez, L.E. and Faria, V.P. De. 1979. Soluble carbohydrates of four
cultivars of elephant grass (Pennisetum purpureum Schum.) cut at three
maturity stages. Solo 71(1):4548. (Portuguese) Herb. Ass. 01839(051).
- Holm, L.G., Plunknett, D.L., Pancho, J.V., and Herberger, J.P. 1977. The
world's worst weeds. Univ. Press of Hawaii. Honolulu.
- Miyagi, E. 1980. The effect of planting density on yield of napier grass
(Pennisetum purpureum Schumach). Sci. Bul. Coll. Agr., U. Ryukus No.
- Seiler, R.J., Omar, A.R.S., and Salim, N. 1979. Nitrate poisoning in cattle fed
napier grass (Pennisetum purpureum). Kajian Veterinar. 11(1/2):1013.
- Stewart, G.A., Gartside, G., Gifford, R.M., Nix, H.A., Rawlins, W.H.M., and
Siemon, J.R. 1979. The potential for liquid fuels from agriculture and forestry
in Australia. CSIRO. Alexander Bros., Mentone, Victoria, Australia.
- Venkatesh, B. and Shetty, H.P.C. 1978. Studies on the growth rate of the grass
carp (Ctenopharyngodon idella Valenciennes) fed on two aquatic weeds and
a terrestrial grass. Aquaculture 13(1):4553.
- Watt, J.M. and Breyer-Brandwijk, M.G. 1962. The medicinal and poisonous plants
of southern and eastern Africa. 2nd ed. E.&S. Livingstone, Ltd., Edinburgh
Last update Wednesday, January 7, 1998 by aw