Department of Primary Industries, P.O. Box 149, Mareeba. Qld. 4880.
A range of ntroduced grasses was tested under cutting and grazing at five sites in the 1970's with fertilizer applied at sowing only. In sward experiments with 12 lines, the most persistent and productive were Brachiaria decumbens and Paspalum plicatulum. Nitrogen levels in mature whole tops were below 1% in both sown and native grasses and ranged from 1.1 to 2.2% in associated legume.
In row experiments using 86 lines under uncontrolled grazing, best spread occurred in the high yielding Andropogon gayanus and Hyparrhenia rufa (by seedlings) and the moderate yielding Bothriochloa insculpta, Brachiaria humidicola and Chloris gayana (by stolons). Other persistent but slower colonizing grasses included B. decumbens, Dichanthium aristatum, P. plicatulum, Urochloa mosambicensis, U. oligotricha and U. pullulans. Accessions of Cenchrus, Panicum and Setaria failed to persist. Most of the persistent perennial grasses were readily accepted by stock and retained some greenness in the dry season when native grasses were dormant, with A. gayanus pre-eminent Stylosanthes hamata cv. Verano persisted with the sown grasses.
Sparse establishment of sown grasses occurred in these experiments and in commercial sowings. It is suggested that the ability of a sown grass to spread is most important in the dry tropics particularly if sown grasses are to be used in relatively low input pasture systems.