Great Plains and Inter-Mountain Region

The largest areas of natural grass and range lands in the United States are in the Great Plains and the Inter-Mountain region, a vast area where the soil is usually productive but rainfall is a limiting factor. The plant breeder finds there a wealth of material that can be used in a program to improve grass. These grasses can be broadly classified as cool-temperature plants, those that make the most growth during spring and fall, and warm-temperature plants, those that grow best during the summer.

Because the number of desirable grasses in this region is large, I can mention only a few examples to illustrate the efforts to improve them.

Native grasses vary widely in their adaptation. Much of the improvement work therefore has been confined to field selections. Because of variations in winter hardiness, forage production, day length, disease resistance, and other factors, the field selections cannot be moved too far north or south from the region of their origin. Until local tests have proved otherwise, strains we now have should not be planted more than 150 or 200 miles north or south from the area of origin.

Intensive work was started on buffalo grass (Buchloe dactyloides) in 1935. Plant breeders want to domesticate this highly variable plant by selection and hybridization. Because of the wide variation in almost every known character in buffalo grass, selection has been used most extensively. Improvement work has been under way in North Dakota, Nebraska, Kansas, Oklahoma, and Texas—most intensively at Hays, Kans., and Woodward, Okla.

The Hays strain is the only improved one in which seed is available for limited distribution in 1947. It was developed at the Fort Hays Agricultural Experiment Station at Hays, in cooperation with the Department. At least 5,000 pounds of foundation seed were produced for distribution annually at that station in 1944, 1945, and 1946.

The main aim of the workers who developed the Hays strain was to breed a type that bears abundant seed on stems for easier harvesting. The strain has been superior to common or field buffalo grass in production of seed and forage. It is said to equal common buffalo grass in resistance to disease, and has the ability to produce seed high off the ground. Other selections of buffalo grass made at the Hays station appear to be even more promising than the Hays strain.

The Southern Great Plains Field Station at Woodward started to increase the seed of three strains of buffalo grass that appeared promising in the preliminary stages of development. One of them gave evidence of being a particularly outstanding cross because it has tall, quick spreading plants bearing seed on the stalk 6 to 8 inches above the ground. It is an aggressive strain—sprigs set out at 5-foot intervals completely fill in the space between them in about 3 months.

Blue grama (Bouteloua gracilis) is a warm-season, short grass found growing in association with buffalo grass. It forms a good sod, although it is a typical bunchgrass. Many strains of blue grama occur naturally, but southern strains generally lack winter hardiness when they moved north, and northern strains yield less when grown in the South. Seed is hard to get, because blue grama fails to set seed consistently; the development of desirable seed-producing strains is of major importance. So far, it has been impossible to obtain lines either by selection or hybridization that are superior in seed production under irrigation or dry-land conditions. Intensive studies will have to be made to develop strains of this important range grass.

Side-oats grama (Bouteloua curtipendula) is another native, perennial, warm-season grass that ranks high in palatability. It is easily established by seed and forms an important part of the mixture recommended for range land reseedings. Strains from the South are subject to winter injury when moved north, and northern strains are low in production when moved southward.

El Reno side-oats grama was developed from field collections made near El Reno, Okla. It has ranked higher than other strains tested in Kansas for leafiness, resistance to leaf disease, and seed production.

Switchgrass (Panicum virgatum) is a native long-season grass that grows alongside the bluestems. It resembles other native grasses in growth and adaptation, but it differs from them in that it is a good seed producer, and the seed can be easily harvested, cleaned, and sown.

One strain that is being propagated is known as Blackwell switchgrass in Kansas. It is a field selection from Blackwell, Okla., developed by the Soil Conservation Service at Manhattan, Kans. It has a fine leafy quality and considerable resistance to rust. It matures seed moderately late and yields well. The leaves remain green until frost. In Kansas, and perhaps in nearby States, it is adapted for use in mixtures. It has been accepted for certification by the Kansas Crop Improvement Association. Another field selection, made from Holt County, Nebr., is a small, leafy type that is well adapted to the sandy soils north of the Platte River in Nebraska. It is susceptible to rust when grown farther south.