R.J. CLEMENTS¹, W.H. WINTER² and R. REID³

¹CSIRO Division of Tropical Crops and Pastures, Cunningham Laboratory, 306 Carmody Road, St. Lucia, Qld 4067;
²CSIRO Division of Tropical Crops and Pastures, Darwin Laboratories, P.M.B. 44, Winnellie, N.T. 5789;
³CSIRO Division of Tropical Crops and Pastures, Davies Laboratory, Private Mall Bag, Altkenvale, Qld 4814.

Abstract

Twenty-one accessions of five Centrosema species were evaluated in cutting trials for 2–3 years at three sites (Katherine, Lansdown and Narayen Research Stations) in northern Australia, together with Stylosanthes hamata cv. Verano and Macroptilium atropurpureum cv. Siratro. At Katherine, several C. pascuorum accessions had herbage yields equalling or exceeding those of Verano, and had soil seed reserves of 1 t ha^-1 or more during the third dry season. C. brasilianum and C. schottii accessions were lower yielding but were persistent and productive for the duration of the experiment. The two C. virginlanum accessions failed to persist. At Lansdown, establishment was poor but two C. schottii accessions, one C. brasilianum accession and Verano produced herbage yields exceeding 1 t ha^-1 in the second growing season. At Narayen, Siratro was the only successful legume.
In a second experiment, ten C. pascuorum accessions were grown in short rows on three soil types at Narayen Research Station and harvested for mineral nutrient analysis before flowering. There were no significant differences in N content of accessions. P, K and S contents of each accession are reported, and the mean concentrations of an additional nine elements are listed.