Breeding and evaluation of Digitaria eriantha for improved spring yield and seed production

Summary

Digitaria eriantha is a subtropical grass which is widely sown as a pasture species in South Africa and cultivars have recently been released in Australia. The species is variable in seed production and in other agronomic attributes. This paper describes a breeding program designed to combine the seed production of cv. Premier with the high productivity in winter-spring of an almost sterile genotype.

Hybrids between the two accessions were either triploid and sterile, or diploid with low fertility. The F₂ to F₅ generations were selected intensively for fertility and, at two contrasting sites, for spring productivity, with both maternal and paternal selection. The F₆ generation was grown as replicated swards and yield in spring, and fertility, were used for selection of elite F₅ plants to comprise the parents of a new cultivar (cv. Advance).

In evaluation trials, spring dry matter production of Advance averaged 40% higher than that of Premier. On average, seed production of Advance was 11% lower than that of Premier and botanical fertility was consistently about half that of Premier. Experimental yields of cleaned seed of Advance were up to 138 kg/ha. In commerce, seed yields of Advance are likely to be lower than those of Premier unless higher inflorescence densities than Premier can be achieved.