EVALUATION OF 13 STYLOSANTHES-SCABRA ACCESSIONS IN 5 DRY TROPICAL ENVIRONMENTS

Sown pasture development in light-textured soils of seasonally dry tro pical Queensland is based mainly on the Stylosanthes genus. Seca shrub by style is the cultivar of Stylosanthes scabra most widely sown. This paper presents 3-5 years data on 13 accessions of S. scabra in 5 envi ronments from a larger evaluation of 46 accessions grown across 11 dry tropical sites in an attempt to broaden the environmental range of th is species over that covered by Seca. Although there was abnormally lo w rainfall during the experiment, the styles established, perenniated and survived in all environments except near Prairie. CPI 92477 was th e only accession to have consistently higher rankings than Seca for se edling and perennial plant populations and dry matter yields. However, it was less resistant to anthracnose than Seca. The plant densities a nd dry matter yields recorded annually in environments suitable for S. scabra suggest that pasture improvement could be possible in environm ents previously considered marginal, such as the seasonally dry tropic s receiving 500-750 mm rainfall. The better environmentally adapted ac cessions could be used also in future selection and breeding work with S. scabra.