Abstract
The degree of winterhardiness, forage yield and quality of 12 winterhardy selections of Panicum maximum Jacq. originating from 158 plant introductions established in the field in 1971 were assessed. These selections had been defoliated at 5-week intervals and survived an average January temperature of zero °C and a minimum temperature of -8°C better than the remainder of the selections. The winterhardy clones ranged in dry matter yield from 12.5 to 22.61 ha-1 with minimal fertilization and no irrigation. The in vitro dry matter digestibilities of five-week old forage for the selections ranged from 62 to 65%. All 12 clones had 2n = 32 chromosomes and reproduced by apomixis. They have excellent forage potential or could be used as male parents in crosses with sexual genotypes to produce needed gene combinations. The discovery of clones evaluated in this study with more winterhardiness than previously reported broadens the area of adaptation and utilization of this species.
