Submitted to: American Society of Agronomy Monograph Series
Publication Type: Other
Publication Acceptance Date: 10/18/2003
Publication Date: 9/22/2004
Citation: Hanna, W.W., Chaparro, C.J., Mathews, B.W., Burns, J.C., Sollenberger, L.E. 2004. Perennial pennisetums. American Society of Agronomy Monograph Series. Interpretive Summary: This chapter summarizes the important perennial pennisetum species that serve as forage species in either a hay or grazing setting. Discussed are Napiergrass, Kilkuyugrass, Flaccidgrass, and P. orientale. Consideration is given to taxonomy, morphology, adaptation, breeding, insect and disease resistance, nutritive value and animal responses through grazing or stall feeding. Management factors as fertilization and defoliation frequency by harvesting mechanically or through grazing animals are also discussed.
Technical Abstract: The genus Pennisetum is reported to have more than 140 species, however, this may be an over estimation because some taxonomists assigned species names to races. Species in this genus have base chromosome numbers of x = 5, 7, 8, and 9 with ploidy levels ranging from diploid to octaploid. The base number of most species is x = 9. Species can be annual or perennial and reproduce sexually, by apomixis, or by facultative apomixis. Most species make a contribution to forage production in their native habitats, some with greater potential than others. Napiergrass or elephantgrass [Pennisetum purpureum(L.) Schum.] is valued as a forage crop in the wet tropics of the world and is the second most important species in the genus behind pearl millet [P. glaucum (L.) R. Br.]. Kikuyugrass (P. clandestinum Hochst. ex Chiov.) provides high quality pastures and turf at higher altitudes in the tropics and subtropics. Flaccidgrass (Pennisetum flaccidum Griseb.) and P. orientale L.C. Rich) are other species that make important contributions to pasture and forage production in some parts of the world. All are small-seeded, polyploid, apomictic, and have the basic chromosome number of 9. Breeding can be difficult in these apomictic species, but low levels of sexuality can be found which allows for the production of new genotypes by hybridization. Even in obligate apomictic species, new hybrid types can be produced through fertilization of unreduced eggs.