Dichanthium caricosum (L.) A. Camus

Andropogon caricosus L.

Family: Poaceae (alt. Gramineae) subfamily: Panicoideae tribe: Andropogoneae.

Nadi blue grass (Fiji);  Antigua hay grass (West Indies);  jiribilla (Cuba);  roadside bluestem (USA).

A creeping stoloniferous perennial with blue-tinged stems and fine pointed leaves, 4–20 cm long, 2–6 mm wide.  Stolons can grow to 1.5–2 metres;  nodes are generally hairless.  Slender seed stems grow to 45 cm.  1–3 racemes, usually 2, 2–10 cm long, on a many-jointed rachis.  Spikelets paired, one sessile and one stalked.  Spikelets are all very close together and overlap each other.  Only the sessile spikelet has an awn , 1–2.5 cm long.
D. caricosum has erect, semi-erect and spreading forms in northern India.

Native to:
South Asia:  India, Sri Lanka.
Indo-China:  Myanmar, Thailand.
Malesia:  Indonesia, Malaysia, Papua New Guinea.

Naturalised in:
West Indies and in Fiji and other Pacific Islands.  Dominant grass in savannas of north-east Java, Indonesia.  Becoming popular in the Chaco region of northern Argentina.

A semi-improved perennial grazing pasture with excellent ground cover.  For permanent pastures and erosion control.

Generally found on heavier (black) clays of moderate fertility.  Such soils are generally slightly acid to alkaline, with no Al problems.  Drainage can be poor under high rainfall .  Said to be found on sandy soils in southern India.  Poor salt tolerance.

Well adapted to 1,500–2,500 mm rainfall with a moderate dry season of 5–6 months.  D. caricosum will tolerate seasonal waterlogging and short-term flooding.  It survives the dry season well but gives little production over that time.

Warm season tropics to 1,000 m asl ;  also subtropical in northern Argentina.  Not tolerant of frost.

Preferably full sunlight but will grow under moderate shade.

Short-day.

Very tolerant of heavy grazing while providing good ground cover.

Can be burned but fire is usually cool because of low fuel loads.

Guidelines for the establishment and management of sown pastures.

Can be planted from seed or stolons.  Seed is awned and hence difficult to harvest and clean mechanically.  De-awned seed is less likely to clump but the spiralled awn may help the seed to bury itself when wetted.  Not easy to establish from seed, although in time it would spread from a relatively low density to form a close sward under suitable conditions.  Planting stolons with nodes gives faster establishment but requires follow-up rainfall and is more labour intensive.

Fertiliser is not needed when the grass is planted on suitable soils.

Rapid and full ground cover tends to keep out other species including weeds or twining or erect legumes.  Heavy grazing and lack of fire can lead to increases in woody weeds, eg. guava (Psidium guajava) in Fiji.

Legumes:  Desmodium heterophyllum , D. triflorum , Alysicarpus vaginalis , Mimosa pudica, and possibly with Arachis spp.  Also can be grown between rows of Leucaena.

Susceptible to root-knot nematodes on lighter soils.  Downy mildew fungus (Sclerospora sorghi) identified in Thailand.

Good spread from initial planting through stolons.  Probably able to spread from seed.

No information available.

Good nutritive values during the wet season.

Palatable and readily eaten by cattle, sheep, goats and horses.

None recorded.

10–12 t/ha/year DM but very poor production during the dry season.  In Fiji, production is highest in March at about 1,000 kg/ha/week and lowest from July–September at about 200 kg/ha/week.  In Guadeloupe, it produced up to 40 kg/ha/day DM during the wet season, but none during the 5 months of dry season.

LWGs of 100 kg/ha/yr from unimproved grassland at a stocking rate of 2.5 steers/ha;  150 kg/ha/yr with legumes (sown Macroptilium atropurpureum and naturalised Desmodium heterophyllum ) and superphosphate.  Animals may lose weight during the dry season because of lack of growth of grass .

No information available.

Fluffy seed can be hand-harvested with sickles or mechanically harvested with a brush harvester.

No information available.

• Well adapted to heavier soils.
• Very tolerant of heavy grazing.
• Easy to establish.
• Good control of herbaceous weeds.
  

• Poor production during the dry season.
• Fluffy seed is difficult to handle.
• Susceptible to nematodes on light soils.
  

Bisset, W.J. and Sillar, D.I. (1984) Angleton grass (Dichanthium aristatum ) in Queensland. Tropical Grasslands, 18, 161-174.

Partridge, I.J. (1979) Improvement of Nadi blue grass (Dichanthium caricosum ) pastures on hill land with superphosphate and siratro: effects of stocking rate on beef production and botanical composition. Tropical Grasslands, 13, 157–164.

Partridge, I.J. and Ranacou, E. (1974) Effects of supplemental Leucaeana leucocephala browse on steers grazing Dichanthium caricosum in Fiji. Tropical Grasslands, 8, 107–112.

Vivier, M. and Doreau, M. (1979) Natural Dichanthium caricosum grassland in Guadeloupe. Agronomie Tropicale, 34, 362–371.

http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl?dichanthium+caricosum
http://www.inta.gov.ar/benitez/info/documentos/nutri/art/AANB42.htm
http://www.fao.org/ag/AGP/AGPC/doc/Gbase/data/pf000215.htm

Cultivars	Country/date released	Details
‘Marvel 40’ (CPI 106073)	India (1971)	Produce 40-100% more dry matter than the naturally occurring strain.
‘Marvel 93’ (CPI 106075)	India (1971)	Produce 40-100% more dry matter than the naturally occurring strain.
‘Alabang X’	Philippines	This may be D. caricosum   and not D. aristatum .

Promising accessions	Country	Details
	Paraguay and northern Argentina	On heavier clay soils in the Chaco