Paspalum dilatatum

Cultivation Details

Paspalum dilatatum grows best in the subtropical zone in regions without a dry season, or with only one or two monhs without rain. It is often cultivated and can succeed from the tropics to the warmer parts of the temperate zone; it can be found at elevations up to 2,300 metres. It grows best in areas where annual daytime temperatures are within the range 20 - 30°c, but can tolerate 13 - 36°c^[1]. It is one of the most frost tolerant subtropical grasses and, when dormant, its deep root system can survive temperatures down to about -10°c, although young growth can be severely damaged at -3°c^[1]. It prefers a mean annual rainfall in the range 900 - 1,300mm, but tolerates 750 - 1,700mm^{[2, 1]}. Prefers a position in full sun, tolerating light shade^[1]. Succeeds in a wide range of at least moderately fertile soils^[1]. Prefers moist growing conditions but farily tolerant of dry soils^[3]. Prefers a pH in the range 5.5 - 7, tolerating 4.3 - 8.3^[1]. Established plants are tolerant of drought and occasional inundation of the soil^[2]. The plant is considered a minor pest of lawns and other utility turf^{[3, 1]}. It commonly invades irrigated pastures^[4]. It produces large quantities of seed, which can attach themselves to clothing, animal fur etc, and spreads readily by this means where conditions are suitable for germination. Vegetative spread is extremely slow. Although a slow establisher and with the impediment of disease of the inflorescence, it has been a remarkably successful coloniser^{[3, 4]}. A long-day plant, it has an optimal daylength of 14 hours^[2]. Growth of young plants is slow, but once they are established the growth is vigorous and many leaves are produced in a short time^[2]. Established plants have their fastest growth rate early in the growing season, but growth slows down during mid-summer and autumn. During the cool period in subtropical regions and at higher altitudes the plants are dormant. Flowering occurs throughout the growing period and seeds scatter as soon as they are ripe. With declining soil fertility, the vigour of the plant declines and it is then often invaded by other species^[2]. Yields of fresh herbage can range from 39 - 65 tonnes per hectare^[2]. Paspalum dilatatum can be divided into two varieties, var. Dilatatum and var. Pauciciliatum Parodi. The latter has 2n = 40 chromosomes and is more prostrate. It has slightly smaller and less hairy spikelets, more spikelets per raceme and its lemma and palea have three veins compared with nine in var. Dilatatum. This variety is better adapted to light and poorly drained soils than common Dallis grass. Important cultivars of var. Dilatatum are 'Raki' from New Zealand, 'Charu' from Uruguay and 'Natsugumo' from Japan^[2].