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

Sown pasture development in light-textured soils of seasonally dry tropical Queensland is based mainly on the Stylosanthes genus. Seca shrubby 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 environments from a larger evaluation of 46 accessions grown across 11 dry tropical sites in an attempt to broaden the environmental range of this species over that covered by Seca. Although there was abnormally low rainfall during the experiment, the styles established, perenniated and survived in all environments except near Prairie. CPI 92477 was the only accession to have consistently higher rankings than Seca for seedling and perennial plant populations and dry matter yields. However, it was less resistant to anthracnose than Seca. The plant densities and dry matter yields recorded annually in environments suitable for S. scabra suggest that pasture improvement could be possible in environments previously considered marginal, such as the seasonally dry tropics receiving 500-750 mm rainfall. The better environmentally adapted accessions could be used also in future selection and breeding work with S. scabra.