Panicum maximum x P. infestum


Scientific name

Panicum maximum x P. infestum

Panicum maximum Jacq.
Panicum infestum Andersson

Synonyms

Megathyrsus maximus x M. infestus
Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs
Megathyrsus infestus (Peters) B.K. Simon & S.W.L. Jacobs

Family/tribe

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

Common names

guinea (English);  capim-massai (Brazil);  herbe de guinée C1 (French);  pasto guinea (Spanish).

Morphological description

A leafy, densely tillered, perennial tussock, mostly 60–90 cm tall, to >1.5 m at maturity, and 40 cm basal diameter.  Culms fine, to 2.5 mm diameter.  Leaves linear to 90 cm long and mostly 5–10 mm wide;  blade with scabrous upper surface;  sheath covered with short, dense, radiating hairs.  Inflorescence an open panicle with the main axis to >25 cm long, and lower racemes to 20 cm long (may vary with cultivar);  secondary branching of the racemes absent or much reduced.  Spikelets similar in size and appearance to those of P. maximum , often purplish in colour.  900,000 seeds/kg.

Distribution

Available accessions originate from Tanzania and Kenya.
Used in monsoonal and dry tropical environments in West Africa, Brazil, and Vietnam.

Uses/applications

Mostly used for permanent pasture, for grazing or cut-and-carry.  High proportion of fine leaf suggests value for hay and silage if cut young.  Agroforestry in palm plantations.  Also provides stable ground cover in sub-humid and seasonally dry environments.

Ecology

Soil requirements

Grows best in fertile, well-drained soils.  Tolerates lower N and P fertility than cultivated varieties of P. maximum , but responds to applications of both nutrients.  Also more tolerant of lower pH and higher aluminium saturation than is P. maximum .

Moisture

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Very drought tolerant, growing in environments with annual rainfall of 600–900 mm, with 5–7 months dry season.  Best grown in more humid environments with 1,000–2,000 mm rainfall .

Temperature

Growth is strongly warm season dominant.  Best below 23° latitude, and from sea level to 1,000 m asl .

Light

Shade tolerance not recorded.  Probably moderate to good as in P. maximum - used in palm plantations in West Africa.

Reproductive development

‘Massai’ (see Cultivars) flowers through much of the growing season at 20–23ºS, with a peak flowering from March to May.  More restricted flowering period in higher latitudes.  ‘C1’ flowers in March/April at Walkamin (17ºS, Australia), and at the end of the rainy season in October at Dakar (15ºN, Senegal).

Defoliation

In a grazing system, it should be maintained between 15–20 cm and 50–60 cm.  A grazing rotation (1 week on / 4–5 weeks rest) is a good point to start, adjusting according to stock class and numbers, fertiliser use and rainfall .  A similar cycle should be followed for cut-and-carry (see Nutritive Value).

Fire

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No information available.

Agronomy

Establishment

Sown in rows 40 cm apart at 2–4 kg/ha or planted from splits on a 40 cm grid.  Seed dormancy may be similar to that in P. maximum , so seed should be kept for several months after harvest before sowing.

Fertiliser

Responds to application of phosphorus in low P soils.  If all other nutrients are non-limiting, productivity is strongly related to nitrogen availability, with good responses up to 150–300 kg/ha/yr N.

Compatibility (with other species)

Competes strongly for moisture and nutrient, and can have high levels of basal cover.  Can form association with legume if managed to suit the legume .

Companion species

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Grasses:  Not usually planted with other grasses.
Legumes:  Arachis pintoi , Pueraria phaseoloides , Stylosanthes hamata .

Pests and diseases

Few pests or diseases of any consequence.  ‘C1’ has resistance to root-knot nematode (Meloidogyne spp.), and ‘Massai’ to the spittlebug (cigarrinha), Notozulia entreriana.

Ability to spread

Spread only by seed.  Can spread from parent stand with little or no disturbance.

Weed potential

No indications of weediness.

Feeding value

Nutritive value

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Nutritive value is usually lower than for P. maximum at similar stage and under similar conditions, but rate of decline is less than for most cultivars of P. maximum .  It varies markedly with part of plant and age of regrowth.  CP level in leaves, 12.5%, and in stems, 8.5%, and in whole plant, 11% in 4-week regrowth and 5% in 12-week regrowth.  IVDMD mostly in the range of 50–55%.

Palatability/acceptability

Well eaten by cattle, sheep and horses.

Toxicity

No record of toxicity.

Production potential

Dry matter

Yields mostly of the order of 10–20 t/ha/yr, depending on moisture and amount of fertiliser used.  Up to 50 t/ha DM in dry tropics with adequate N and irrigation.  Higher yields than many P. maximum lines in similar environment.

Animal production

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Cattle can gain 400 g/day in wet season (3 AU/ha) and at least maintain weight in the dry season (1 AU/ha);  >600 kg/ha/yr at up to 4 AU /ha.

Genetics/breeding

May be dealing with new species or spontaneous hybrid between P. maximum and P. infestum.  ‘C1’ is tetraploid (2n = 4x = 32), 97% apomictic.

Seed production

Seed sheds as it matures, so large losses, particularly with windy weather, as in P. maximum .  Harvested in May in southern hemisphere.  Seed yields of 80–100 kg/ha.  Direct heading can provide 75% of the harvested yield, and threshing of windrows the remainder.

Herbicide effects

No record, but probably similar to those for P. maximum .

Strengths

  • Drought tolerant.
  • Low, dense, very leafy.
  • Palatable when young.
  • Better ground cover than P. maximum .
  • Better adapted to low P and high Al than P. maximum .
  • More tolerant of low pH and high Al saturation than P. maximum .

Limitations

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  • Not tolerant of waterlogging or poor drainage.
  • Nutritive value declines rapidly.

Other comments

Cultivars have near identical appearance, but have all been evaluated separately, and under different conditions.

Selected references

  

Internet links

Cultivars

Cultivars

Country/date released

Details

‘C 1’
(ORSTOM T 19)
Côte d’Ivoire (1980s) Derived from T 19, collected Bagamoyo, near Dar-es-Salaam, Tanzania.  A natural P. maximum x P. infestum hybrid discovered by ORSTOM in the collection of Adiapo-Doumé (Côte d’Ivoire) near Abidjan probably in 1975.  A vigorous, productive type, evaluated in Côte d’Ivoire, Senegal, Nigeria, French Guiana, and New Caledonia.  Used in palm plantations in West Africa.
‘Massai’
(ORSTOM T21, BRA-007102)
Brazil (2001) From Bagamoyo, near Dar-es-Salaam, Tanzania.  A natural P. maximum x P. infestum hybrid. Perennial , up to 60 cm tall, very leafy, long, thin leaves up to 0.9 cm wide, purplish seed heads.  Selected on the basis of persistence in less fertile, more acid soils in areas where spittlebugs (cigarrinhas), Notozulia entreriana, are a problem in Brachiaria brizantha cv. Marandu. Spittlebug tolerance similar to that of ‘Tanzania’ (P. maximum ), and greater than that for ‘Mombaça’ (P. maximum ).  Tolerant of intensive grazing, and suitable for cattle, sheep and horse grazing.

Promising accessions

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Promising accessions

Country

Details

K 280 Vietnam Popular in cut-and-carry dairy systems around Ho Chi Minh City.  Rainfall 1,900 mm, 5 month dry season.