|
Cenchrus ciliaris L. |
  |
Graminae Pennisetum cenchroides Rich.; P. ciliare (L.) Link. Buffel grass (Australia), African foxtail (United States, Kenya), dhaman grass, anjan grass, koluk katai (India). The genus Cenchrus belongs to the tribe Paniceae, in which the two-flowered spikelets fall when ripe, leaving no glumes. The spikelets are solitary and the pedicels never swollen. Cenchrus resembles the genus Pennisetum, except that the bristles are wavy and the inner ones flattened at the base. Cenchrus ciliaris has slightly hairy inner bristles, connate at the base only, fine and only slightly flattened at the base. It is a tufted or spreading perennial 12-120 cm tall (Harker & Napper, 1960). It is deep rooting. Hotter and drier parts of India, Mediterranean region, tropical and southern Africa, now widely introduced. Summer. Sea-level to 2 000 m. In Queensland it grows in the 375-750 mm rainfall regime with 60 percent or more of the annual rainfall falling in summer. It does not do well in high-rainfall areas. For good establishment, buffer seed needs to be moist for about five days and a minimum of 30 mm of rainfall is needed for a C. ciliaris pasture to respond to nitrogen fertilizer. For high growth rates soil moisture must be adequate for 30 consecutive days (Henzell et al., 1975). The buffer grasses are very drought resistant. Lighter textured soils of high phosphorus status are best, but it thrives on the clay loams and clays of the cleared brigalow (Acacia harpophylla) and gidgea (A. cambagei) scrubs of inland Queensland. It is slow to establish on the black cracking clays, but when established it does well, for example in central Tanzania. The optimum soil reaction is pH 7 to 8, but it grows on soil with a pH as low as 5.5. Ramia and Fernandez (1974) and Spain and Andrew (1977) showed buffer grass to be very sensitive to soils containing high levels of aluminium. C. ciliaris spreads well by seed where the soil pH ranged from pH 7-8 in Tanzania (Brzostowski, 1962). Land preparation for establishment Most of the buffer grass in Queensland has been aerially sown into the ashes left after a scrub burn. However, a rough seed- bed can be prepared by ploughing or disc-harrowing, and hollows left by uprooting tree stumps and by the tracks of a bulldozer when clearing scrub are effective seed- beds. Soil disturbance is generally essential for initial establishment. Aerial sowing is common and under ideal conditions an aircraft can sow up to 1 600 ha per day at rates as low as 200 g/ha, in strips. Costs vary according to distance from the landing airfield. Because the seed is light, wind direction is important. Seed can be sown through special buffer seed drills fitted with agitators in the seedbox to separate the seed, or with an augur device to perform the same function (Paull & Lee, 1978). It can be hand-broadcast into fallen timber, under big trees such as Eucalyptus populnea where fertility is higher (Ebersohn & Lucas, 1965; Christie, 1975b) due to mineralization of fallen vegetation and livestock camping (see Plate 28) and into stump holes. Further methods of planting can be found in a paper by Paull (1973). It will not establish under E. crebra (Humphreys, 1978). It is surface sown and lightly harrowed or rolled where possible. It is best sown just ahead of the expected rainy season at 0.5-4 kg/ha, according to seed supplies, costs, and expected rate of full ground cover. 450 000 to 703 000. Seed treatment before planting Where seed-harvesting ants are prevalent, dusting with 20 percent lindane dust at 1 kg per 80 kg of seed is recommended to reduce seed removal. Pelleting with lime to increase seed weight and reduce soil acidity has been successful in lateritic red earths. Germinate for ten days at 40°C. Seed treatment by hammer milling for semi-arid planting is not recommended, as it is more attractive to ants and a good initial germination may end in the total loss of seedlings (Paull & Lee, 1978).G Buffel grass often invades urban areas in a semi-arid environment and becomes a weed. Control is possible with 2,2 DPA or with paraquat (Gramoxone) applied before flowering when the soil is moist. Diuron can be used as a pre-emergence spray to destroy germinating buffer. In establishing buffer grass pasture, any broad-leaved weeds can be controlled, if necessary, with 2,4-D at 1 kg active constituent per hectare, if the buffer seedlings have developed at least four leaves (Paull & Lee, 1978). Atrazine at 4 kg/ha used as a post- emergence spray affected survival of C. ciliaris but at 1 kg/ha it was less damaging (Scateni, 1978). Buffel grass seedlings usually have good vigour. Vigour of growth and growth rhythm New, fully-expanded leaves developed at the rate of every nine to ten days in summer, 11 days in spring and 14 to 12 days in autumn, with senescence highest in the summer growing season and slowest during the cooler dry autumn (Wilson & 't Mannetje, 1978). Buffel grass will stand considerable grazing once it is established. Newly established pastures can be used during the winter and spring following planting and, if necessary, locked up during the following summer to seed and increase plant density. Frequent grazing improves nitrogen content. Cuttings at 10 cm at intervals of 20 days in a wet year and 30 days in a dry year gave highest yields in Rajasthan (Dabadghao, Roy & Marwaha, 1973). Where the area of buffer grass is small, it is best to graze the native pastures during the summer growing period and keep the buffer grass, especially the cold-tolerant varieties, for use during the winter. On hard setting soils some renovation with a fined implement will promote plant growth if done after rains in spring and summer. Do not overdo the renovation. An occasional fire to retard the development of woody plants and destroy old grass is generally necessary. Graze according to herd needs (Humphreys, 1967). Nitrogen fertilizers will be required to maintain productivity or increase it. Buffel grass will stand the burning of the old vegetative grass. The crowns will not be adversely affected and nutritive value may improve. Dry-matter and green-matter yields At Narayan, Queensland, Henzell (1976-77) recorded an increased annual dry matter production by Biloela buffer grass from 4.80 t/ha to 9.08 t/ha with the application of 168 kg N/ha each year over a six-year period. In the forest region of Ghana, Asare (1970) cut 10-cm buffel grass at six- week intervals. With a complete fertilizer (135 kg N/ha, 73 kg P/ha and 11.7 kg K/ha), the yield was 24 200 kg DM/ha; unfertilized it was 18 800 kg DM/ha. In India, a yield of 2 010 kg DM/ha was obtained by cutting at 60-day intervals (Shankarnarayan et al., 1977). Suitability for hay and silage Buffel grass makes reasonable-quality hay when cut in the early flowering stage, yielding up to 2 500 kg/ha per cut with a protein content of 6-10 percent of dry matter. Old grass, after the seed has been harvested, can give low-quality roughage for drought feeding with supplements. This old grass will have a protein content of 4-6 percent. Little buffer grass has been made into silage, as the moisture content in the semi-arid areas is usually low. Value as a standover or deferred feed It is a valuable standover feed for winter grazing and for roughage along with supplements such as urea-molasses. Buffel grass has caused bighead disease in horses due to a high oxalate content. The symptoms are ill thrift, lameness, and swelling of the skull. Disease is most prevalent during the wet season when the buffer is young and lush. To control it, vary the diet away from pure buffer grass, or feed a supplement of ground limestone or dolomite (Walthall, 1977). Playne (1976) found oxalate levels in buffer grass ranged from 1.2 to 2.8 percent total oxalate and 1.2 to 2.2 percent water-soluble oxalate. 10-60 kg/ha of clean seed per harvest. Seed remains viable for two to three years (Jones, 1973).
introduced from Dodoma in Tanzania in 1937 by CSIRO, Australia and tested at Rockhampton, Queensland. It is a tall-growing type named after the Biloela Research Station, Queensland, where it was further developed. It grows in a wide range of soils and will adapt to poorer soils. 703 000 seeds per kg.
introduced from Kenya and extensively propagated and proved by W.H. Rich of "Boorara" cattle ranch in central Queensland. It will grow on poorer soils than the other cultivars.
introduced to Australia from Uganda and tested by CSIRO, Australia chiefly on the property of B.C. Clark of "Nunbank", Taroom, Queensland. It will grow on poorer soils as well as on fertile ones.
dwarf strains suitable for semi-arid conditions in Africa.
seed came from Kenya and was tested by the Queensland Department of Agriculture and Stock and developed principally on the property of Sir William Gunn at Tarewinnabar, Goondiwindi. It has greater frost tolerance than most of the other cultivars except 'Molopo'. Seed is scarce and seed production low.
seed came from near the Molopo River, western Transvaal, and was developed by the New South Wales and Queensland Departments of Agriculture. It has good frost tolerance along with 'Tarewinnabar'. It gives poor seed production and prices of seed are high. 535 000 seeds per kg.
seed came from the Department of Agriculture, Pretoria, South Africa. Commercial seed is not available. It is identical with the American cultivar T3782, blue buffel, and is very similar to 'Molopo'.
a tall, leafy cultivar adapted to the 500-625 mm rainfall area in South Africa.
seed came originally to Australia from Kenya, was grown at the Gayndah state school and developed mainly by a local grazier, C.J. Pinwell. This shorter variety is very suitable for sheep grazing. 479 000 seeds per kg.
a fine, leafy variety from Zimbabwe.
introduced to Australia from America and is identical with the American material T.4464. It is a short variety, very suitable for sheep. Its palatability may lead to its overgrazing and disappearance. 454 000 seeds per kg.
a true-breeding apomictic variety developed from the sexual plant found in Texas by a rancher, Pat Higgins, and used by Dr E.C. Bashaw (Burton, 1970).
believed to have arrived in Australia as seed and hay in an Afghan camel harness between 1870 and 1880. A very short variety and one of the first cultivars to be used in western Queensland on cleared gidgea (Acacia cambagei) country. It is the least drought- tolerant of them all. Milford (1960a, b) found this cultivar the most nutritionally valuable of all the cultivars.
has given the best results on the red Barth veils at Kongwa, Tanzania under an annual rainfall of 561 mm. It is a fine-leaved, erect type of medium height which produces ample seed and has excellent drought resistance (Wigg, 1973).
(Kitale introduction no. K.5148, Kenya) does not seed well but has a robust habit which gives it added resistance to overgrazing. There are also several hybrids in existence which are being tested in the United States and Australia (Paull & Lee, 1978). In Kenya the seed is often destroyed by attacks of smut in wetter areas (Bogdan & Pratt, 1967). Blast (Piricularia sp.) and rust (Uredo sp.) occur in Thailand (Vinijsanond, 1978). Its hardiness, deep-rooting, ability to grow in semi-arid conditions, and generally free-seeding habit. Its persistence and resistance to trampling (e.g. around stock-watering points), and drought tolerance. Its difficulty in establishment on heavy soils and its ultimate dominance under conditions which suit its persistence. The difficulty of removing it for cultivation and its depressing effect on a following crop (Humphreys, 1967). Optimum temperature for growth Ludlow and Wilson (1970b) found growth at 30°C was 12.5 times that at 20° for cv. Biloela.à Minimum temperature for growth 5-16°C (Russell & Webb, 1976). It is affected by frosts, but killed only in areas of prolonged frosting. The tall-growing varieties are less affected. In the semi-arid areas it usually dominates weeds. Maximum germination and quality required for sale 20 percent germinable seeds, 90 percent purity (Queensland). Pre-dry fresh seed and germinate at 20-35°C, moistened with water (Prodonoff, 1966). It has few pests. It is very palatable when young, and remains fairly palatable at maturity. Chemical analysis and digestibility For Biloela buffel grass unfertilized, buffer grass + 84 kg N/ha per year, buffer grass + 168 kg/N per year, and buffer grass + siratro, t' Mannetje's (1977). Open bush and grassland. Anderson (1974) showed that buffer grasses are killed after six days' flooding in the field. The tall, rhizomatous cultivars ('Tarewinnabar', 'Nunbank', 'Boorara', 'Biloela' and 'Molopo') are more tolerant than the short, non- rhizomatous 'Gayndah' and 'American'. Rhizome development is not the reason, as 'Molopo', with the best rhizome development, was the least flood tolerant of the tall cultivars. At short flood durations, plants were more severely affected if completely covered by water than if some parts of the leaves were exposed. Where flooding in the field occurs irregularly and does not last more than six days, buffer grasses can be used in pasture mixtures. FAO No. 8693, collected at 680 m, 8 km south of game post, Ewaso, Ngiro, came from seasonally flooded ground. Buffel grass is not often fertilized in a semi-arid environment. Henzell (1976-77) showed that application of 167 kg N/ha increased the annual yield of buffer grass from 9 780-15 250 kg DM/ha at Narayen, Queensland, in 1975-76 (average rainfall 710 mm). In Ghana, Asare (1970) obtained highest yield with a complete NPK mixture. The critical value for phosphorus is 0.26 percent of the dry matter. Compatibility with other grasses and legumes Buffel grasses are frequently sown with Columbus grass (Sorghum almum) at 4 kg/ha to give a quick, temporary pasture to recoup establishment costs. The S. almum lasts for one or two years, and then the buffer grass and its other associated grasses can take over. Buffel grass at 1.5-2 kg/ha can also be sown with Rhodes grass at 0.5-1 kg/ha, Bambatsi panic, green panic or Urochloa mosambicensis. Eventually the buffer grass is likely to become a pure stand. Few legumes will persist with it for longer than 12 months unless well managed. In subtropical areas, Medicago sativa, Macroptilium atropurpureum and some annual Medicago spp. may last a little longer. The chromosome numbers are 2n = 32, 36, 40, 54. It is apomictic in general but Dr E.C. Bradshaw in 1961 in Texas discovered sexual reproduction in his plots. The method of reproduction is controlled by two genes and epistasis (Bashaw, Hovin & Holt, 1970). 2n = 32,34, 36, 40, 52, 54 (Fedorov, 1974). Seed production and harvesting Seed plots can be grazed to late spring or early summer when good rains are received. They are then shut up and, if necessary, slashed to obtain an even height when seed is ready to harvest. The seed remains mature on the heads for 14-20 days and can be harvested up to three times a season if rainfall is adequate. Cv. Molopo will retain ripe seed for only six to eight days. Seed can be hand-harvested and such seed should not need cleaning. Most is direct-harvested by machinery either home- built or purchased. Basically, the ripe seed is beaten off on to trays which collect the seed. Refinements include removal of most of the trash and bagging the seed. It is one of the best forage grasses for semi-arid areas in the subtropics and tropics. At Narayan Research Station, Queensland, Biloela buffel grass fertilized with 84 and 168 kg N/ha per year gave an annual live-weight gain of 160 kg/ha at a stocking rate of one beast per hectare, where unfertilized buffel grass produced a weight loss between the months of May and November. The unfertilized native pasture gave an annual live-weight gain of 30 kg/ha ('t Mannetje, 1977). Siratro with buffel grass at an equivalent stocking rate yielded 80 kg more live- weight gain than did buffel grass on its own, and buffer grass with siratro and buffel grass with 168 kg N/ha grazed at the same stocking rate gave similar gains (162 kg/ha at 1.1 steers per hectare) ('t Mannetje, 1972). Removal of glumes improves germination, but is risky in arid areas (Pandeya & Pathak, 1978). Anthocyanins and phenolics in the seed coat inhibit germination (Pandeya & Pathak, 1978). Freshly harvested seed has poor germination and after-ripening for three to 12 months is desirable. Seed older than two years should be tested for germination. Scarification will also break dormancy (Humphreys, 1978). Buffel grass is valuable in that it is one of the best adapted grasses to semi-arid conditions. Its tussocky nature, however, does not allow for complete ground cover (Robinson, 1978). The buffel grasses are less tolerant to salt than Rhodes grass, Bermuda grass and blue panic. Cv. Biloela is more tolerant than other cultivars, maintaining relatively high yields up to 80 meq sodium chloride per litre (Graham & Humphreys, 1970).
Humphreys, 1967; Paull, 1973; Paull & Lee, 1978. |