L.A. EDYE

CSIRO Tropical Agriculture, Townsville, Queensland, Australia

Abstract

Approaches to the development of new Stylosanthes cultivars from large collections of naturally occurring genotypes are described. The climatic, edaphic and biotic constraints to adaptation are summarised and the criteria for the selection of 'new' cultivars are discussed.
The process of evaluation used in northern Australia is described. It consisted of 3 stages: (a) nursery rows; (b) small sward trials; and (c) grazed pastures. The statistical techniques used for analysing multi-site small-sward experiments are described, as well as the limitations to adaptation caused by ineffective root-nodule bacteria in species that have highly specific Bradyrhizobium requirements.