Narrowleaf Carpet Grass
Axonopus affinis

Summary


Common Name

Its common name is narrowleaf carpet grass, carpet grass, mat grass (Bodgan).

Scientific Name

The scientific name is Axonopus affinis Chase (Bogdan).

Cultivars

No information is available in this database on this topic. FAO reports no cultivars recorded.

Seed Description

No information is available in this database on this topic.

Seedling Description

Seedlings are reported to be very vigorous (FAO).

Mature Plant Description

Narrowleaf carpet grass is a perennial, stoloniferous, short spreading grass. Its leaves are 5-20 cm (2-8 in.) long and 2-6 mm (1/16 - 1/4 in.) wide. It ranges in height from 25-75 cm, forming a dense mat over the ground surface (FAO). Spikelets are 2.0-2.2 mm long (Bogdan). The fertile floret is white to pale yellow colored (FAO).

NOTE: A. compressus (broadleaf carpet grass) and A. affinis (narrowleaf carpet grass) cannot be easily distinguished from one another by their general appearance because the leaf width can vary and hybridization occurs (Bogdan).

Temperature

Found in the tropics and subtropics (FAO). A. affinis is slightly more frost tolerant than broadleaf carpet grass (A. compressus) and therefore also found in the cooler regions of these areas (Bogdan).

Origin and Geographic Distribution

Narrowleaf carpet grass is thought to have originated in the American tropics (southern United States, the West Indies or Central America). It is now distributed throughout the tropical and subtropical regions of America, Africa, Asia, Australia and the Pacific Islands (FAO).

Ecology

According to the FAO, its natural habitat is the subhumid and humid woodland and savannah.

Water

Narrowleaf carpet grass requires a minimum rainfall of 750 mm/yr (about 30 in/yr) but is more drought resistant than broadleaf carpet grass (A. compressus). It prefers moist soil but does not withstand prolonged flooding or permanently swampy conditions (FAO).

Nutrients

Narrowleaf carpet grass can compete well on infertile soils (Bogdan) and its presence in a pasture indicates declining soil fertility throughout the tropics (FAO). It does respond to fertilizer applications, particularly N, but its efficiency of N use is low compared with other pastures (FAO).

Soil pH

Narrowleaf carpet grass tolerates soil pH range 4.0 - 7.0 (NRCS).

Soil Type

Narrowleaf carpet grass grows on a range of soil types, particularly sandy soils (FAO).

Shade Tolerance

Fair shade tolerance (NRCS).

Salinity Tolerance

No information is available in this database on this topic.

Herbicide Sensitivity

No information is available in this database on this topic.

Life Cycle

No information is available in this database on this topic.

Seeding Rate

Seeding Depth

Surface sow with minimum cover (FAO).

Seeding Method

Broadcast and harrow or roll (FAO).

Seeding Dates

Year round in Hawai`i.

Inoculation

Not applicable.

Seed Cost

No information is available in this database on this topic.

Seed Availability

Readily available.

Days to Flowering

No information is available in this database on this topic.

Days to Maturity

No information is available in this database on this topic.

Seed Production

Narrowleaf carpet grass produces seed readily, the seed can be readily harvested, and in the USA combine-harvesting in practiced (Bogdan). The FAO reports that seed is harvested mechanically in Mississippi and Louisiana, USA.

Seed Storage

No information is available in this database on this topic.

Growth Habit

Narrowleaf carpet grass is a short spreading grass that reaches a height ranging between 25-75 cm (about 10-30 in.), forming a dense mat over the ground surface (FAO).

Maximum Height

Narrowleaf carpet grass grows to a maximum height of about 75 cm (30 in.) (FAO).

Root System

Narrowleaf carpet grass has a shallow root system (96% of roots in the 0-5 cm layer) (FAO).

Establishment

Narrowleaf carpet grass can be seeded or vegetatively propagated by planting stolons (Bogdan).

Maintenance

Apply 224 kg/ha (about 200 lb/ac) superphosphate at sowing and annually (FAO).

Mowing

No information is available in this database on this topic.

Grazing: Narrowleaf carpet grass should be kept in the vegetative state by frequent grazing and periodically renovated and fertilized with N, especially in spring to prolong its feeding value (FAO).

Incorporation

Not applicable. Not generally used as a green manure.

Harvesting

Not applicable. Not generally harvested for hay because when high enough to harvest, it is low in nutritive value (FAO).

Equipment

No information is available in this database on this topic.

Uses

Mixtures

In low fertility conditions, narrowleaf carpet grass tends to outcompete legumes and invade Paspalum dilatatum pastures and Cynodon dactylon lawns. Few legumes can compete with its dense sod (FAO). It tends to become suppressed by companion grasses on good or well-fertilized soil (Bogdan).

Biomass

No information is available in this database on this topic.

N Contribution

No information is available in this database on this topic.

Non-N Nutrient Contribution

No information is available in this database on this topic.

Effects on Water

No information is available in this database on this topic.

Effects on Soil

No information is available in this database on this topic.

Effects on Livestock

A. affinis does not provide high quality pasture. Animal live-weight gains from narrowleaf carpet grass are low compared with other pasture species and live-weight losses occur in winter. Live-weight gains from pure pasture alone have been 84-98 kg/ha per year unfertilized. After seed set crude protein may fall as low as 4 or 5 percent. It is considered a good horse feed because horses eat the masses of seed-heads avoided by cattle (FAO).

Pest Effects, Insects

No information is available in this database on this topic.

Pest Effects, Nematodes

No information is available in this database on this topic.

Pest Effects, Diseases

FAO reports no major diseases.

Pest Effects, Weeds

Excellent for weed suppression but can become a troublesome weed itself. It often invades run-down old sown unfertilized pastures (Bogdan).

Pest Effects, Vertebrates

No information is available in this database on this topic.


Uses in the Pacific Region

No information is available in this database on this topic.

Uses in Hawai`i

The Hawai`i Natural Resources Conservation Service Technical Guide includes narrowleaf carpet grass. Their specification describes narrowleaf carpet grass as follows:

Evans reports carpet grass being used successfully in Kona by coffee growers, with the more wear-resistant Tropic lalo (Paspalum hieronymii) being used for access roads and equipment-bearing areas.


References

Bogdan, A.V. 1977. Tropical Pasture and Fodder Plants. Longman Inc., New York. Pp.44-45.

Evans, Dale O., Joy, Robert J., & Chia, C.L., 1988. Cover Crops for Orchards in Hawaii. Hawaii Institute of Tropical Agriculture and Human Resources, University of Hawaii at Manoa, Honolulu, Hawaii, United Stated. pp. 14.

FAO Grassland Index Web Site

USDA Natural Resources Conservation Service, Hawai`i Field Office Technical Guide, Section IV, Code 340 "Cover and Green Manure Crop" May 1992. Pacific Islands Area Field Office Technical Guide (eFOTG) - East Area

Information Last updated on 9/23/02

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These webpages were originally generated under a grant program from Western SARE entitled "Covering New Ground: Tropical Cover Crops for Improving Soil Quality" EW98-012 (1998-2002).