|Nakagawa, Hitoshi - RES CTR AGR SCI JAPAN|
Submitted to: Grassland Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 23, 2003
Publication Date: February 1, 2004
Citation: Kindiger, B.K., Russo, V.M., Nakagawa, H. 2004. Performance and persistence of Japanese cool-season grass forages in the central great plains of Oklahoma, USA. Grassland Science. 50(3):271-279. Interpretive Summary: Annually sown winter wheat is the primary cool-season forage utilized by livestock enterprises in central Oklahoma. The annual expense associated with wheat pasture has increased producer interest in the utilization of alternative sources of cool-season grass forage. Few productive and persistent cool-season forage grasses are available for the Oklahoma livestock industry and as a consequence, there is a need to identify and develop germplasm which is tolerant to the climatic extremes of the region. A cooperative research study between USDA-ARS, Grazinglands Research Laboratory, El Reno, OK, and the Japanese National Grassland and Livestock Research Institute, was initiated to evaluate the performance and persistence of selected Japanese cultivars as a breeding resource for this region. A four year forage performance trial evaluated nine cool season cultivars under the climatic extremes of Oklahoma. In addition, yearly nitrogen applications were limited to induce an additional stress component that would mimic poor pasture management practices. The study identified one orchardgrass, two fescue and one Italian ryegrass cultivars which had value, productivity and persistence during the trial. One cycle of mass selection was performed among the materials to develop and distribute a second generation of germplasm resources possessing a greater tolerance to heat and drought.
Technical Abstract: In this study, the performance of nine Japanese cool-season grass cultivars representing five species were evaluated in central Oklahoma, USA. Forage production, persistence data and climatological data were obtained to identify the performance of Japanese cool-season grass forages and their possible use as a breeding resource. Data from the four year study indicate 'Akimidori' orchardgrass, 'Nanryo' tall fescue, 'Harusakae' meadow fescue and 'Shiwasuaoba' annual ryegrass have value and a capacity for additional breeding improvements for both central Oklahoma and Japan. Akimidori orchardgrass, Nanryo tall fescue and Harusakae meadow fescue each exhibit tolerance to drought and heat stress. As a consequence, these cultivars indicated good persistence in the years evaluated. Shiwasuaoba annual ryegrass, by virtue of its early maturity, escaped periods of drought and heat stress in central Oklahoma and was well suited to no-till forage-grass-vegetable rotations. Multi-year performance testing of cool-season Japanese grasses in the climatic extremes of central Oklahoma provide a useful selection tool for drought and heat tolerant germplasm for both Japanese and American breeding programs.