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Brachiaria humidicola (Rendle) Schweick. |
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Graminae B. dictyoneura (Fig. and De Not.) Stapf. Koronivia grass (Fiji), creeping signal grass (southern Africa). A procumbent stoloniferous perennial with lanceolate leaf blades, three to four racemes with hairy spikelets 3.5-4 mm long (Napper, 1965). It is distinguished from other species of the genus by its creeping habit. The rachis is narrow and angled. The lower glume is three-fourths as long as the spikelet, and conspicuous because it is purple or purple-brown in the upper part, contrasting with the light green colour of the rest of the spikelet. The leaf-blades are flat, and at least 5 mm wide, often more (Chippendall & Crook, 1976). Tropical Africa. Summer. 1 000-2 000 m. It is adapted to the wetter zone of Fiji. It has good drought tolerance (CIAT, 1978) and remains green better than other species with better dry-season production in Fiji (Partridge, 1979b). While it does well on deep fertile soils, it proved to be well suited to coral rubble soil of high pH in less-shaded old coconut plantations in the Solomon Islands (Gutteridge & Whiteman, 1978). Being intensely stoloniferous, it covers the ground well on red soils but is slow to colonize heavy black soils in Fiji. Land preparation for establishment A rough ploughing is sufficient to accommodate the vegetative material planted. It is usually established vegetatively, small bundles of stolons being planted at spacings of 1-2 m (Roberts, 1970a, b; Partridge, 1979a). The cuttings are planted at 15-20 cm with a spade, and covered. Sow in the wet season (November to March) in the dry zone, and at any time in the wet zone, in Fiji. Good (CIAT, 1978). Vigour of growth and growth rhythm It grows well in summer, and flowering does not normally commence till November in Fiji. It will withstand heavy defoliation. It withstands heavy grazing except in areas where Navua sedge (Cyperus aromaticus) is a threat in Fiji (Partridge, personal communication). It will not tolerate burning (CIAT, 1978). Dry-matter and green-matter yields In Fiji it produced 10 929 kg DM/ha unfertilized and achieved a yield of 34 018 kg/ha with an application of 452 kg N/ha with a linear response to nitrogen up to that peak yield (Roberts, 1970a, b). In 1972 at Sigatoka, Fiji, when fertilized with 450 kg/ha superphosphate, it produced 17 500 kg DM/ha, of which 49 percent was produced in the dry (winter) season (Partridge, 1979a). At CIAT, Quilichao, Colombia, selection 679 yielded 2 500 kg DM/ha during an 18-week period without phosphorus, and over 5 000 kg DM/ha with the application of 50 kg P2O5/ha (CIAT, 1978). No toxicity has been reported. In Colombia, Ferguson (1979) obtained 10-50 kg/ha. Selections are being made at CIAT, Colombia. It is resistant to diseases. Its strongly stoloniferous habit, with ability to root at the stolon nodes, covers the ground rapidly and competes particularly well with weeds. Its low phosphorus requirement and resistance to spittle bug. Its low seed production. Optimum temperature for growth About 32-35°C in Fiji. Minimum temperature for growth It has some cool-season productivity (Roberts, 1970a, b). In less-shaded coconut plantations it performs very well (Gutteridge & Whiteman, 1978). It forms a dense, somewhat woody mat layer beneath grazing level and effectively suppresses weeds (Roberts, 1970a, b). It has no serious insect pests. It is resistant to spittle bug (Deois incompleta) in the Brazilian humid tropics (Serrão et al., 1979). It is palatable when young, but of low palatability at maximum productivity (Roberts, 1970a, b). Selection 679 has low dry-matter digestibility and low nitrogen content at CIAT, Quilichao, Colombia (CIAT, 1978). Valley grassland in moist situations, road verges, and vleis. Good, but not as great as Brachiaria mutica. It responds well to high nitrogen applications and is much more productive than Batiki blue grass (Ischaemum indicum) (Roberts, 1970a, b). It has excellent tolerance to aluminium (Spain, 1979) and has low phosphorus requirements. Compatibility with other grasses and legumes Because of its dense growth it is difficult to establish legumes with it. Sod-seeding siratro and centro into it has had some success if the grass is mown closely, but weed invasion by Mimosa pudica is a problem in Fiji (Roberts, 1970a, b). It combines with Desmodium heterophyllum in Fiji (Partridge, personal communication). In Zimbabwe it combines well with Trifolium semipilosum and Lotononis bainesii (Clatworthy, 1970). 2n=72 (Fedorov, 1974). Seed production and harvesting It is a shy seeder, and this factor alone contributes to its slow spread (Roberts, 1970a, b). The seed also has low viability. It is used for grazing in Brazil, Fiji and other parts of the world. Selection 679 was to be subjected to grazing trials at CIAT, Colombia during 1979 and subsequently. Links for the genus:
CIAT, 1978; Clatworthy, 1970. It would prove a very effective grass for erosion control (Chippendall & Crook, 1976). |