Abstract
In order to identify subtropical grass species and varieties which would be productive, frost-tolerant and would grow vigorously under relatively low temperature conditions, twenty-two subtropical grasses were compared for their growth characteristics, seasonal production and winter hardiness. Field experiments were conducted at two contrasting sites. One relatively cold site was at Canberra, A.C.T. (Ginninderra) and site with relatively mild winter temperatures was at Berry, N.S.W. The species and varieties tested comprised 10 varieties of Chloris gayana, 5 Setaria sphacelata, 2 Cenchrus ciliaris, and one each of the following, Paspalum dilatatum, Panicum maximum var. trichoglume, P. coloratum, Sorghum almum and Digitaria argyrograpta. The more productive grasses were varieties of Chloris gayana, Sorghum almum and "Kazungula" Setaria sphacelata (N.810). The only grasses able to survive a cold winter were Paspalum dilatatum and Digitaria argyrograpta. Those tolerating mild winter temperatures in addition to those two specise were "Nzoia" and "Pioneer" Chloris gayana, Sorghum almum, Panicum coloratum and all five lines of Setaria sphacelata. It is suggested that further exploration of highland tropical regions could provide lines of Chloris gayana and Setaria sphacelata capable of high summer production in the warm temperate areas of Japan.
