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Bracheri mutica (Forsk.) Stapf

Syn.: Panicum barbinode Trin.
Panicum purpurascens Raddi
Panicum muticum Forsk.
Poaceae
Paragrass

Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.


  1. Uses
  2. Folk Medicine
  3. Chemistry
  4. Description
  5. Germplasm
  6. Distribution
  7. Ecology
  8. Cultivation
  9. Harvesting
  10. Yields and Economics
  11. Energy
  12. Biotic Factors
  13. References

Uses

Considered one of the best tropical grasses for general purposes, especially during the dry season. Used for green soilage, hay or browse. Grazed rotationally as it will not withstand heavy grazing; relished by livestock. Grown as valuable fodder crop in many parts of the tropics; introduced into Assam. Does not make good silage (Bogdan, 1977), and not very good for hay.

Folk Medicine

No data available.

Chemistry

CP ranges from 2.8–16.1%, CF from 28–34%, NFE from 41–57% and EE from 0.9–3.9%, P content as high as 0.8% are reported (Bogdan, 1977). According to Kothandaraman et al. (1973), the moisture content at 30 days is 9.4%, DM content 90.6%, ash 14.5%, CP = 14.2, fat 7.2%, CF 19.3%, N-free extract 44.8%, CaO = 0.70%, P2O5 = 1.1%, K2O = 3.4% and MgO = 0.8%.

Description

Perennial grass, rather coarse, with well developed root; culms 0.6–2.4 m tall, rooting at nodes, branches, robust, geniculate at base, then ascending, slender, bare at top, compressed, striate, glabrous; nodes covered with long white hairs, spreading, linear or linear-lanceolate, acuminate, subcordate at base, flat, glabrous or slightly hairy on undersurface, scaberulous, 15–25 cm long, 1.25–1.6 cm broad, margins hispid; sheaths compressed, striate, lax, glabrous or hairy at throat ligules short, very hairy; inflorescence a panicle made up of 8–20 false spikes or racemes, simple or compound at base, erect or somewhat spreading, alternate, distant, robust, lower 5–10 cm upper shorter; principal axis almost rounded, angular at summit, almost straight, striate, glabrous; rachis of raceme striate, back convex, ciliate on margins and with a few long hairs at base; pedicels short, paired, solitary or fasciled, with acute, 2.5–3 mm long, glabrous; lower glume 0.6–1 mm long, membranous, ovate-acute, 1-nerved; upper glume 2.5–3 mm long, membraneous, concave, ovateacute, 5-nerved; lower floret male or neuter; lemma 2.4–2.7 long; palea 2.2–2.7 mm long, narrower than lemma, hyaline, 1-nerved; upper flocoriaceous, oblong or elliptic, obtuse, pitted, margins hardly incurved; palea subcoriaceous, back flat, pitted, elliptic, obtus, margins inturned. 2n = 36.

Germplasm

Reported from the African Center of Diversity, paragrass or cvs thereof is reported to tolerate drought, laterite, low pH, poor soil, shade, waterlogging and weeds (Duke, 1978). Several cultivars have been developed: 'TARS' in Australia; 'Sao Palo' in Brazil; and 'Medellin' in Columbia. A form from Rippon Falls is widely cultivated in Southern Rhodesia under name of 'Tanner grass', and is much more palatable than usual strains.

Distribution

Native to tropical Africa and perhaps tropical South America (perhaps introduced), but now widely distributed throughout tropics as fodder grass. Classified as a serious weed in Australia, Fiji and Thailand, a principle weed in Sri Lanka, Colombia, Hawaii, Jamaica, Malaysia, Peru, Philippines, Puerto Rico, and Trinidad, a common weed in Borneo and Mauritius (Holm et al, 1979); it is a weed in 23 crops in 34 countries (Holm et al, 1977). According to Brown (1975) Roundup at 2.5–5 kg/ha gives good control of paragrass.

Ecology

Ranging from Subtropical Dry to Wet through Tropical Very Dry to Wet Forest Life Zones, paragrass is reported to tolerate annual precipitation of 8.7 to 41.0 dm (mean of 16 cases = 19.9) annual temperature of 18.7 to 27.4°C (mean of 16 cases = 24.4) and pH of 4.3 to 7.7 (mean of 14 cases = 6.0). An ideal perennial grass for wet areas in tropics and subtropics, suitable for swamps and floodplains in coastal regions. Withstands both drought and prolonged flooding or waterlogging, but makes little growth during dry weather. Very frost sensitive. Can become a troublesome weed, especially when established in irrigation ordrainage channels fron which it can rapidly infest cultivated fields.

Cultivation

Although paragrass produces profuse flower-heads, it is a poor seed producer. As seeds are rarely viable, plantings are made most often from cuttings. Cuttings along any part of the stem with 2 or 3 nodes used as propagules give satisfactory rootings; those near the tip developing earlier. Also cuttings placed vertically as opposed to horizontally, develop faster and are more vigorous. Some strains in Australia do set viable seed, about 20% germination. Nitrogen fertilizer is sometimes applied. In India, 100 kg/N/ha increased yield by 49.2%, TDN by 79.2% and CP by 23.3%. When planted by seed, seeding rate is about 2–4 kg/ha. When propagated by stem cuttings, they are placed about 2 m by 2 m apart, or cut stems are scattered over surface and covered by disking. Old stands may be renovated by heavy disking or shallow plowing. In Queensland paragrass is grown in combination with Centrosema pubescens or Trifolium fragiferum.

Harvesting

Grazing paragrass should not be started until grass has produced a complete ground cover, sometimes up to a year from planting. Low cutting or grazing swards is recommended, cuts at 1–7 cm yield 20% higher than cuts at 15–20 cm over the year.

Yields and Economics

Yields range from 6–12 MT/ha/yr in Australia (Miller, 1976), 4–26 in Cuba; 16 in Surinam and 38–40 in Puerto Rico. Bogdan reports yields of 9–135 MT fresh herbage/ha, 3–39 MT DM. Wealth of India reports 34 MT green fodder from Poona, 87 from Malaya and 104 from British Guiana. In spite of such high potential Bogdan (1977) says yields of 5–12 MT DM/ha are more to be expected. This compares well with the 6–12 MT yields reported in 4-year swards irrigated in Australia (Miller, 1976). More importantly Novoa and Rodriguez-Carrasquel (1972) got 8-week yields of 1–6 MT DM/ha during the dry season in Venezuela (fertilized and irrigated). Sotomayor Rios et al. (1973) report CP yield >2.5 MT/ha/yr in Puerto Rico. With heavy fertilization and ample moisture or irrigation, this grass will yield up to 150 MT/ha/WM, and may be cut at monthly intervals. Under ordinary conditions, it may be cut at 6–8 week intervals. It compares well in quality with other tropical fodder grasses. Crude protein is highest when about 30 days old at 14.19%. For highest nutritive values this grass should be cut for feeding after 30 days, but this may vary with soil and other environmental conditions. An important tropical fodder grass, especially for wet areas. Cultivated mainly in tropical Africa, Northern Australia and tropical South America, providing large quantities of nutritious forage and fodder.

Energy

According to the phytomass files (Duke, 1981b), annual productivity ranges from 4 to 39 MT/ha (4–26 in Cuba, 39 in Puerto Rico, 16 in Surinam). An NPP of 8–12 MT/ha is reported for B. brizantha in Sri Lanka, 7–24 MT/ha is reported for B. decumbens in Brazil, 1–20 in Colombia, 4–32 in Cuba, 12 in Jamaica, 9–15 in Peru, 10–20 in Sarawak, 36 in Surinam. For B. humidicola, 11 MT/ha/yr is reported in Brazil, 11–34 in Fuji. For B. radicans, 15 is reported in Brazil, 34 in Puerto Rico. For B. ruziziensis, 2 is reported in Australia, 14 in Surinam. Much of this could be siphoned into energy production.

Biotic Factors

Following fungi have been reported on paragrass: Cerebella andropogonis, Corticium solani, Gibberella pulicaris, Helminthosporium sp., Marasmius sacchari, Mayriogenospora paspali, Myrothecium striatosporum, Nigrospora oryzae, N. panici, Perisporium zeae, Pythium artorogus, Pithium (Nematosporanglum epiphanospon, N. hyphalosticton, N. leiohyphon, N. polyandron, N. rhizophthoron, N. spaniogamon, N. thysanohyphalon), Piricularia grisea, P. oryzae forma brachiariae, Uromyces leptodermus. It is also attacked by the bacterium, Pectobacterium carotovorum var. graminarum. Nematodes isolated from this grass include: Dolichodorus nigeriensis, Helicotylenchus pseudorobustus, Hemicriconemoides cocophilus, Scutellonema clathricaudatum, Tylenchorhynchus sp., and Xiphinema ifacolum. Holm et al (1977) list it as an alternate host of Cassytha filiformis, Helminthosporium sp., Piricularia oryzae, Pythium arrhenomanes, Pythium artotrogus, Pythium rostratum, Sclerospora graminicola and Thaia oryziphon

References

Complete list of references for Duke, Handbook of Energy Crops
Last update December 30, 1997