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Cenchrus setigerus Vahl |
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Graminae C. setiger Vahl. Birdwood grass (Australia), mode dhaman grass (India). Cenchrus setigerus is a tufted perennial up to 60 cm tall with flat or folded leaf-blades. False spike dense, 1.5-9 cm long; spikelets 3-4.5 mm long, surrounded by a rigid involucre 3.5-5 mm long, the outer bristles minute or absent, the inner flattened, grooved on the back. Each cluster of spikelets contains one to three caryopses. The inner bristles, in contrast to C. ciliaris, are glabrous connate for 1-3 mm from the base, flat and rigid throughout (Harker & Napper, 1960). Northwest India and north-east tropical Africa. Summer. 500-800 m. It is adapted to arid and semi-arid climates with a long dry season and responds very quickly to light rains. It is very tolerant of drought and will grow in areas of annual rainfall as low as 200 mm, making it excellent for improvement of low rainfall grazing land. It is more tolerant than C. ciliaris. It prefers light-textured sandy soils but does well over a wider range of soils than C. ciliaris (Suijendorp, 1953). Birdwood grass spreads only slowly where seed is incorporated in the soil by animal treading or cultivation. Land preparation for establishment The land needs some cultivation or the seed can be sown aerially or by hand in the ashes of a burn, for example after felling and burning Acacia cambagei scrub in brown clay soils of central Queensland, Australia. Sow aerially in ashes or through modified cereal drills. Hand broadcasting is suitable for small areas. Seed is usually sown on the surface and covered with harrows or bushes dragged across the sown area. Seed should not be covered to a depth greater than 2 cm. Sow just before the usual rainy periods in summer at the rate of 1.5-3.0 kg/ha depending on seed supplies, cost and rapidity of cover desired. 350 000. Seed treatment before planting It can be treated with lindane dust to deter removal by seed-harvesting ants. The young seedling is quite vigorous. Vigour of growth and growth rhythm It is not a vigorous grower and its tussocky nature does not provide a great deal of bulk. Birdwood grass, once established, withstands grazing well. Cutting at 30-day intervals gave the highest yields in Rajasthan, and cutting height (5, 10 or 15 cm) made no difference. Once established, birdwood grass can stand heavy grazing. To thicken the stand it should be allowed to seed every two to three years. Fire will remove the dry top growth, but unless the fire is very severe the plants will recover well after rain. Dry-matter and green-matter yields In India, cutting at ten-day intervals yielded 400 kg DM/ha and cutting at 60-day intervals (during 1970-72) yielded 2 120 kg DM/ha (Shankarnarayan, Dabadghao & Kumar, 1977). At Jodhpur, Rajasthan, average monthly yields per plant were 45 g, 3.2 g and 11.9 g in 1968-69 (rainfall 178.8 mm), 1969-70 (92.7 mm) and 1970-71 (504.8 mm) (Gupta, Saxena & Sharma, 1972). At Victoria River Downs, Northern Territory, Australia, it yielded 679 kg DM/ha per year over three years (Pearson, Hill & Allen, 1979).Iö Suitability for hay and silage Birdwood grass, if in areas which can be mown, makes useful hay, though the yield is not high. No record is available of its use for silage. Value as a standover or deferred feed Because of its hardy nature and ability to grow in low-rainfall areas, birdwood grass is a valuable standover feed in these areas. Care must be taken to prevent grass fires in these arid climates. No toxicity has been reported. Birdwood grass matures in eight weeks and seeds heavily. The seed can be hand picked or harvested mechanically with cereal harvesters or special grass-seed harvesters. The seed is a cluster of spikelets surrounded by hard scales. Introductions into Australia exhibit two distinct seed clusters one is light straw-coloured and the other brown or black (Barnard, 1969). There are no major diseases. Its drought resistance, hardiness and palatability, and its non-fluffy seed, making the seed easier to sow than that of C. ciliaris. Its tussocky nature and lack of bulk. Optimum temperature for growth Probably 30-35°C. It is extremely tolerant of heat and drought. Minimum temperature for growth It does not respond well to winter rain. It survives frost. 30°N and S. Maximum germination and quality required for sale Germination is poor. Germinate at 20-35°C moistened with water. 20 percent germination and 60 percent purity in Queensland. There are no major pests. Birdwood grass is quite palatable and readily accepted by stock. It is grazed in preference to Cynodon plectostachyus in Kenya. It flowers in shortening days. Chemical analysis and digestibility Göhl (1975) notes one record from Dougall and Bogdan in Kenya. Fresh material at the early-bloom stage contained 18.6 percent crude protein, 28.3 percent crude fibre, 11.9 percent ash, 1.9 percent ether extract and 39.3 percent nitrogen-free extract. Open dry bush and grassland, usually on alkaline soils. FAO Nos. 8688 and 8703 at altitude 670-680 m, 8 and 13 km south of game post Ewaso Ngiro, Kenya came from flooded ground. In areas where birdwood grass finds its most valuable niche it is uneconomical to fertilize, but it will respond to nitrogen and phosphorus. Compatibility with other grasses and legumes It will grow with S. humilis but tends to dominate (Norman, 1962b). Birdwood grass is apomictic but pollination is necessary to endosperm formation and seed set. The chromosome number is 2n=34, 36, 37 (Fedorov, 1974). Haploids with C. ciliaris have been found in Kenya. A valuable grass throughout the arid and semi-arid tropics. In the Rajasthan desert area, C. setigerus carries one sheep to 2.6 hectares in Jodhpur, and to 6.01 hectares in Pali. In the Pindan country in the West Kimberleys, Western Australia, characterized by sand plains and sand dunes, birdwood grass introduction with 50 kg double superphosphate per hectare every two years has lifted live-weight gain from 30-50 kg/ha to 72-116 kg/ha, and with mineral supplements live-weight gain reached 146 kg/ha in the wet season, January to May (Holm & Payne, personal communication, 1975). Seed has some physiological dormancy, the germination rate increasing up to two years after harvest. Its tussocky nature, lack of vigour, bulk and persistence makes it of minor value in erosion control, but it would help to set up some barrier against moving sand. It is useful in the Northern Territory of Australia (Robinson, 1978). It occurs frequently on alkaline soils in the Rift Valley, Kenya.
Suijendorp, 1953. |