Heavy grazing pressure being applied by a heifer to a cool season grass selection nursery at Ardmore, Oklahoma.

The goal of the grass breeding program is to develop advanced germplasm and improved cultivars of perennial grasses for the southern Great Plains, and to conduct research supporting this objective. This is to say that we want to develop new and improved grass varieties for the region's farmers and ranchers, and conduct research that is useful to forage breeders throughout the world. The main components of our program involve germplasm evaluation, breeding and selection, evaluation of advanced breeding material, animal performance trials, and seed production research. Our primary focus is to develop cool-season perennial grasses that are persistent and productive in the southern Great Plains.

Germplasm, in this case meaning a group of plants, is evaluated in order to identify material useful to the breeding program. Of 1,505 strains, known as accessions, evaluated for persistence, grazing tolerance, and fall recovery since 1998, we have identified 40 promising accessions. We have begun to use many of these accessions in our breeding work.

A second cycle, or generation, of selection was completed in 2001 for increased persistence, grazing tolerance and fall recovery in populations of several grass species, including hardinggrass (Phalaris aquatica), orchardgrass, smooth bromegrass and tall fescue. In addition, selection has taken place for improved seedling vigor in western wheatgrass, and increased digestibility in tall fescue and tall wheatgrass.

Following selection and seed increase, performance of populations developed by the grass breeding program, as well as currently available cultivars, is evaluated in small plot trials. This evaluation process is crucial in determining the performance and adaptation of a potential cultivar, and is typically the most time-consuming aspect of developing a new forage variety. Testing locations currently include the Noble Foundation's Headquarters Farm and Red River Demonstration and Research Farm in south-central Oklahoma, and an additional location near Iowa Park, in north Texas.

Animal performance trials are conducted to compare beef production and the health of animals consuming different forage varieties. Data were collected during the 2000-01 grazing season from a trial at the Red River Demonstration and Research Farm to compare performance of cattle grazing endophyte- free, endophyte-infected, and novel-endophyte tall fescue. The endophyte is a fungus that lives inside the plant and is transmitted only through seed. It benefits the plant through increased drought tolerance, insect resistance, etc. Unfortunately, the "wild-type" endophyte commonly found in tall fescue also can cause poor weight gains and health problems in grazing animals. The purpose of this research is to determine if tall fescue infected with a novel endophyte has the same persistence, yet minimizes or eliminates the poor weight gains and animal health concerns of tall fescue containing the wild-type endophyte.

A project begun in 1998 examining the effect of spring grazing on seed production of cool-season grasses was completed in 2001. With few exceptions, spring grazing substantially reduced seed yield of 'Paiute' orchardgrass, 'Lincoln' smooth bromegrass, and 'Manska' pubescent wheatgrass. The research was conducted in cooperation with personnel in the Department of Plant and Soil Sciences at Oklahoma State University, and was conducted near Marshall, in north-central Oklahoma.

Also participating in the grass breeding program were research assistants Mack Armstrong and Brian Motes; research associates Dennis Walker and Limei Yun; and student workers Joey Bailey, Michael Robson and John Ruiz.

See: Germplasm Database