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Axonopus affinis Chase

Poaceae
Carpetgrass

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 unpublished.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

The most important use of carpetgrass is for permanent pastures. It is also useful for lawns and erosion control. It is especially good for recreational areas, campgrounds, baseball fields, picnic areas and parking lots. It is not recommended for improved pastures as it is low in nutrients and has low palatability.

Folk Medicine

No data available.

Chemistry

On a zero moisture basis 4-week cut (Malaysia) (28.9% DM) contains 8.3% CP, 30.4% CF, 5.9% ash, 1.7% EE, 53.7% NFE; the 6-week cut (30% DM) contains 7.5% CP, 30.9% CF, 5.9% ash, 1.3% EE, 54.4% NFE; and the Colombian fresh grass (34.2% DM) contains 6.2% CP, 37.2% CF, 5.1% ash, 1.4% EE, and 50.1% NFE.

Description

Shallow-rooted creeping perennial grass, forming very dense sod by rooting at nodes along stolons and by sending up leaf-shoots from the nodes; culms flattened, 30–75 cm tall; tufted flower-bearing culms erect and unbranched; ligule a scale about 0.3 mm long; leaf-blades 6–20 cm long, shorter on the stolons, 3–6 mm broad, flat, blunt or slightly pointed; sheaths keeled; spikes 2 to 4, usually 3, 2–10 cm long, about I mm broad; spikelets 1.7–2.2 mm long, very minutely pubescent around the edges, apically rather blunt, second glume prolonged very little beyond fruit. Fl. spring to fall, as late as Dec. and as early as Feb. 8x = 8. Seeds 2,600,000–2,850,000/kg.

Germplasm

Reported from the Middle American Center of Diversity, carpetgrass or cvs thereof is reported to tolerate heavy soil, low pH, poor soil, and sand. According to Bogdan (1977), A. affinis is more frost tolerant than A. compressus. South American Axonopus scoparius has reported biomass yields of 1–22 MT/ha. (2n = 54,80).

Distribution

Native to Central America and the West Indies; introduced to United States before 1832, first at New Orleans, then spread over southern Coastal Plain and inland to central Alabama and southern Arkansas. Widely distributed now in cut-over timber areas and the like.

Ecology

Ranging from Warm Temperate Dry to Moist through Tropical Moist to Wet Forest Life Zones, carpetgrass is reported to tolerate annual precipitation of 8 to 41 dm (mean of 7 cases = 15.3), annual temperature of 16 to 27°C (mean of 7 cases = 19.7), and pH of 4.3 to 7.0 (mean of 6 cases = 5.6). Warm-season grass, well adapted to sandy or sandy-loam soils with readily available moisture. Also adapted to light textured soils with moisture near the surface in humid tropical and subtropical climates. Drought resistance poor. Thrives under lower fertility levels than do most other pasture grasses adapted to southeastern United States. Does not withstand prolonged flooding or permanent swampy conditions. Most commonly found on slightly acid sandy soils, with pH 5.0–6.0. Adapted also to clays, mucks and peats.

Cultivation

Produces abundant seed which germinate and spread quickly over areas where adapted. Establishes itself readily. Also reproduces by stolons. Seeding rates vary from 5–15 kg/ha when broadcast. Production is low unless it gets adequate fertilizer, but fertilization is not profitable on all sites. Usually it is not fertilized as it is considered a poor-soil grass. On very poor soils, it responds to lime, phosphorus, nitrogen and potassium, the quantities used depending on the soil. Responds well to manuring. It does not respond as efficiently to lime and fertilizers as most other southern forage grasses. However, yields of carpetgrass in Florida have been doubled by use of complete fertilizer applications. Carpetgrass does not occur naturally with legumes. When planted with legumes, such as Kobe lespedeza, white clover and Dutch white clover, yields are increased and quality of forage is improved. When grown in pure stands, carpetgrass is considered of inferior nutritive value, but can be enhanced by close grazing, application of fertilizer and presence of associated legumes. Unfortunately, carpetgrass tends to crowd out Dallisgrass and legumes.

Harvesting

Carpetgrass can be grazed all year by livestock. It is a managed pasture grass in some localities. In Florida it remains green year round; elsewhere, it becomes dormant early in fall and begins growth in spring. A decumbent sod-former, it is very tolerant of frequent defoliation. Even extreme close grazing does not completely defoliate it, as leaves and shoots assume a horizontal position, encouraging new leaf-shoots to develop. Close and frequent grazing stimulates vegetative growth, higher protein content and better yields. For maximum production grazing should be rotated about every 30–40 days, saving at least 50% of current year's growth. A 5–7.5 cm stubble is recommended.

Yields and Economics

Yields of up to 50 MT hay/ha are reported (Duke, 1978). Although carpetgrass lacks feed value, it supplements southern range grazing in summer and fall when range grasses are tough and unpalatable, thus adding considerably to the forage resources of the South.

Energy

According to the phytomass files (Duke, 1981b), annual productivity is 44 to 50 MT/ha, which seems excessively high. However, Bogdan (1977) notes that in mixed stand with other low-growing grasses, A. affinis can compete with Pennisetum clandestinum or Paspalum notatum, other high yielding grasses. Axonopus compressus is estimated to yield at least 2 MT/ha/yr, A. scoparius 1–20 (Duke, 1981b).

Biotic Factors

Following fungi have been reported on Carpetgrass: Cerebellaandropogonis, Balansia strangulans, Curvularia lunata, Dinemasporium graminum var. strigosulum, Fusarium graminum, Helminthosporium ravenelii, Nigrospora sphaerica, Tetraploa aristata, Thanatephorus cucumeris. It is also parasitized by Striga asiatica (lutea). Nematodes isolated from carpetgrass include: Meloidogyne sp., Pratylenchus pratensis, and Radopholus similis.

References

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