Lotononis bainesii (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Lotononis bainesii Baker

Protologue: Fl. Trop. Afr. 2: 6 (1871).

Family: Leguminosae

Chromosome number: 2n= 36

Vernacular names

• Lotononis (En)
• Thailand: thua-lotononit.

Origin and geographic distribution

The natural distribution of lotononis is confined to southern Africa, mainly between latitudes 20°S and 30°S in Namibia, South Africa and Zimbabwe. There are now isolated occurrences in many countries as a result of experimentation. It is naturalized in areas of subtropical Australia, particularly along roadsides.

Uses

Lotononis is used as a pasture legume, mainly in the subtropics.

Properties

Lotononis forage is of better quality than most tropical legumes, particularly in terms of N concentration which ranges from 1.5-4.0%. Digestibility is good for a tropical legume, and Na concentrations also tend to be higher. Seeds are very small with 3000-4000 seeds/g.

Botany

A stoloniferous, prostrate, creeping, short-lived perennial, with a primary taproot and smaller adventitious roots arising from stolons. The plant canopy is seldom more than 30 cm high, but stems may reach 1.8 m length. Leaves usually trifoliolate; petiole up to 7.5 cm long; stipules leafy, up to 1 cm long; leaflets polymorphic, oblong to lanceolate, up to 6.5 cm × 1.5 cm, glabrous or slightly pubescent, margins entire. Flowers about 1 cm long in head-like inflorescences 1-3 cm long with few to more than 20 flowers; peduncle up to 27 cm long; calyx hairy; corolla yellow to reddish. Pod linear-oblong, 8-12 mm × 2 mm, densely white hairy, with long persistent style.

Lotononis flowers early in the wet season.

Cultivar "Miles" has been released in Australia.

Ecology

As a sown pasture species, lotononis is best suited to areas receiving 700-1200 mm annual rainfall in the subtropics or tropical highlands, although it occurs naturally in areas with rainfall as low as 250 mm/year. It is one of the best subtropical legumes in terms of winter growth and is resistant to light frosts. It grows best on well-drained sandy soils under moderate to heavy grazing, particularly with more open grass swards. It has good tolerance of low levels of available soil P and Mo.

Agronomy

Seed is often hard-seeded and scarification may be required before sowing. Lotononis can be established by sowing into a seed-bed or broadcasting into undisturbed swards using a seeding rate of 0.5-1.0 kg/ha. As seed is very small it is best sown on top of cultivated soil and then rolled in so that it is not buried too deeply. Sowing in the hottest months should be avoided. Seedling emergence is often slow and erratic.

Inoculation with a specific Bradyrhizobium strain such as CB 376 is essential. Lotononis is usually sown as a component of a mixture of legumes. It persists poorly with lightly grazed, vigorous grass. The productivity of lotononis tends to be erratic, but once established in a suitable site, it is rarely lost completely. Recovery is aided by a large seed bank in the soil of up to 100 000 seeds per m². The best lotononis years are those with good rainfall early in the wet season; there is less response to rainfall late in the wet season. Lotononis responds to applied P, but will persist on soils of low P status.

Lotononis is most susceptible to diseases during very wet periods if growth is lush. It is susceptible to Cercospora leaf-spot, Botrytis flower blight, Sclerotium rolfsii, Fusarium and Pythium root and stolon rots and legume little leaf.

Genetic resources and breeding

Cultivar "Miles" is available commercially. A germplasm collection is held by ATFGRC (CSIRO, Australia), but preliminary testing suggests that there is no substantial variation within this collection.

Prospects

Lotononis will not be suited to most of South-East Asia, but could be a useful pasture component in the humid subtropics and tropical highlands.

Literature

• Bryan, W.W., 1961. Lotononis bainesii Baker. A legume for the subtropics. Australian Journal of Experimental Agriculture and Animal Husbandry 1: 4-10.
• Bryan, W.W., Sharpe, J.P. & Haydock, K.P., 1971. Some factors affecting the growth of lotononis (Lotononis bainesii). Australian Journal of Experimental Agriculture and Animal Husbandry 11: 29-34.
• Jones, R.M. & Evans, T.R., 1976. Soil seed levels of Lotononis bainesii, Desmodium intortum and Trifolium repens in subtropical pastures. Journal of the Australian Institute of Agricultural Science 43: 164-166.
• Pott, A. & Humphreys, L.R., 1983. Persistence and growth on Lotononis bainesii-Digitaria decumbens pasture. 1. Sheep stocking rate. Journal of Agricultural Science, Cambridge 101: 1-7.
• Skerman, P.J., Cameron, D.F. & Riveros, F., 1988. Tropical forage legumes. FAO, Rome. pp. 319-327.

Authors

R.M. Jones